Merge remote-tracking branch 'origin/master' into soc-2016-cycles_denoising

86 files changed, 1231 insertions, 459 deletions

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 1ab5f8a5b42..d61a7de1a33 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -874,7 +874,7 @@ endif()
 # linux only, not cached
 set(WITH_BINRELOC OFF)
 
-# MAXOSX only, set to avoid uninitialized
+# MACOSX only, set to avoid uninitialized
 set(EXETYPE "")
 
 # C/C++ flags
@@ -1580,7 +1580,7 @@ if(WITH_CXX11)
 	if(CMAKE_COMPILER_IS_GNUCC OR CMAKE_C_COMPILER_ID MATCHES "Clang")
 		# TODO(sergey): Do we want c++11 or gnu-c++11 here?
 		set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++11")
-	elseif(MSVC12)
+	elseif(MSVC)
 		# Nothing special is needed, C++11 features are available by default.
 	else()
 		message(FATAL_ERROR "Compiler ${CMAKE_C_COMPILER_ID} is not supported for C++11 build yet")
diff --git a/doc/python_api/rst/bge_types/bge.types.KX_GameObject.rst b/doc/python_api/rst/bge_types/bge.types.KX_GameObject.rst
index d8cc5e45e83..c5729fd5b19 100644
--- a/doc/python_api/rst/bge_types/bge.types.KX_GameObject.rst
+++ b/doc/python_api/rst/bge_types/bge.types.KX_GameObject.rst
@@ -405,7 +405,7 @@ base class --- :class:`SCA_IObject`
 
       .. note::
 
-         This attribute is experemental and may be removed (but probably wont be).
+         This attribute is experimental and may be removed (but probably wont be).
 
       .. note::
 
@@ -419,7 +419,7 @@ base class --- :class:`SCA_IObject`
 
       .. note::
 
-         This attribute is experemental and may be removed (but probably wont be).
+         This attribute is experimental and may be removed (but probably wont be).
 
       .. note::
 
@@ -453,7 +453,7 @@ base class --- :class:`SCA_IObject`
 
    .. attribute:: childrenRecursive
 
-      all children of this object including childrens children, (read-only).
+      all children of this object including children's children, (read-only).
 
       :type: :class:`CListValue` of :class:`KX_GameObject`'s
 
@@ -536,7 +536,7 @@ base class --- :class:`SCA_IObject`
 
    .. method:: getAxisVect(vect)
 
-      Returns the axis vector rotates by the objects worldspace orientation.
+      Returns the axis vector rotates by the object's worldspace orientation.
       This is the equivalent of multiplying the vector by the orientation matrix.
 
       :arg vect: a vector to align the axis.
@@ -596,7 +596,7 @@ base class --- :class:`SCA_IObject`
 
       Gets the game object's linear velocity.
 
-      This method returns the game object's velocity through it's centre of mass, ie no angular velocity component.
+      This method returns the game object's velocity through it's center of mass, ie no angular velocity component.
 
       :arg local:
          * False: you get the "global" velocity ie: relative to world orientation.
@@ -609,7 +609,7 @@ base class --- :class:`SCA_IObject`
 
       Sets the game object's linear velocity.
 
-      This method sets game object's velocity through it's centre of mass,
+      This method sets game object's velocity through it's center of mass,
       ie no angular velocity component.
 
       This requires a dynamic object.
@@ -814,7 +814,7 @@ base class --- :class:`SCA_IObject`
             # do something
             pass
 
-      The face paremeter determines the orientation of the normal.
+      The face parameter determines the orientation of the normal.
 
       * 0 => hit normal is always oriented towards the ray origin (as if you casted the ray from outside)
       * 1 => hit normal is the real face normal (only for mesh object, otherwise face has no effect)
@@ -911,7 +911,7 @@ base class --- :class:`SCA_IObject`
 
       .. note::
 
-         The gameObject argument has an advantage that it can convert from a mesh with modifiers applied (such as subsurf).
+         The gameObject argument has an advantage that it can convert from a mesh with modifiers applied (such as the Subdivision Surface modifier).
 
       .. warning::
 
@@ -919,7 +919,7 @@ base class --- :class:`SCA_IObject`
 
       .. warning::
 
-         If the object is a part of a combound object it will fail (parent or child)
+         If the object is a part of a compound object it will fail (parent or child)
 
       .. warning::
 
diff --git a/doc/python_api/rst/bgl.rst b/doc/python_api/rst/bgl.rst
index 99f481ce998..0b31e62963c 100644
--- a/doc/python_api/rst/bgl.rst
+++ b/doc/python_api/rst/bgl.rst
@@ -12,7 +12,7 @@ contents: dir(bgl).  A simple search on the web can point to more
 than enough material to teach OpenGL programming, from books to many
 collections of tutorials.
 
-Here is a comprehensive `list of books <https://www.opengl.org/documentation/books/>`__ (non free).
+Here is a comprehensive `list of books <https://www.khronos.org/developers/books/>`__ (non free).
 The `arcsynthesis tutorials <https://web.archive.org/web/20150225192611/http://www.arcsynthesis.org/gltut/index.html>`__
 is one of the best resources to learn modern OpenGL and
 `g-truc <http://www.g-truc.net/post-opengl-samples.html#menu>`__
@@ -2067,7 +2067,7 @@ offers a set of extensive examples, including advanced features.
    :arg length: Returns the length of the string returned in source (excluding the null terminator).
    :type source: :class:`bgl.Buffer` char.
    :arg source: Specifies an array of characters that is used to return the source code string.
-   
+
 
 .. function:: glShaderSource(shader, shader_string):
 
diff --git a/doc/python_api/rst/info_api_reference.rst b/doc/python_api/rst/info_api_reference.rst
index 43469fc0cb7..5ef5866c44a 100644
--- a/doc/python_api/rst/info_api_reference.rst
+++ b/doc/python_api/rst/info_api_reference.rst
@@ -204,7 +204,7 @@ Lets say we want to access the texture of a brush via Python, to adjust its ``co
 
 - Start in the default scene and enable 'Sculpt' mode from the 3D-View header.
 - From the toolbar expand the **Texture** panel and add a new texture.
-  *Notice the texture button its self doesn't have very useful links (you can check the tool-tips).*
+  *Notice the texture button its self doesn't have very useful links (you can check the tooltips).*
 - The contrast setting isn't exposed in the sculpt toolbar, so view the texture in the properties panel...
 
   - In the properties button select the Texture context.
diff --git a/doc/python_api/rst/info_overview.rst b/doc/python_api/rst/info_overview.rst
index b4ae906277d..ba2e6949b81 100644
--- a/doc/python_api/rst/info_overview.rst
+++ b/doc/python_api/rst/info_overview.rst
@@ -19,7 +19,7 @@ This is a typical Python environment so tutorials on how to write Python scripts
 will work running the scripts in Blender too.
 Blender provides the :mod:`bpy` module to the Python interpreter.
 This module can be imported in a script and gives access to Blender data, classes, and functions.
-Scripts that deal with Blender data will need to import this module. 
+Scripts that deal with Blender data will need to import this module.
 
 Here is a simple example of moving a vertex of the object named **Cube**:
 
@@ -80,7 +80,7 @@ To run as modules:
 
 
 Add-ons
-------
+-------
 
 Some of Blenders functionality is best kept optional,
 alongside scripts loaded at startup we have add-ons which are kept in their own directory ``scripts/addons``,
@@ -213,7 +213,7 @@ A simple Blender/Python module can look like this:
        bpy.utils.register_class(SimpleOperator)
 
    def unregister():
-       bpy.utils.unregister_class(SimpleOperator)    
+       bpy.utils.unregister_class(SimpleOperator)
 
    if __name__ == "__main__":
        register()
@@ -327,7 +327,7 @@ Say you want to store material settings for a custom engine.
 .. note::
 
    *The class must be registered before being used in a property, failing to do so will raise an error:*
-   
+
    ``ValueError: bpy_struct "Material" registration error: my_custom_props could not register``
 
 
@@ -429,4 +429,3 @@ Calling these operators:
    >>> bpy.ops.object.operator_2()
    Hello World OBJECT_OT_operator_2
    {'FINISHED'}
-
diff --git a/doc/python_api/sphinx_doc_gen.py b/doc/python_api/sphinx_doc_gen.py
index 432cceece1c..3cb98c677c1 100644
--- a/doc/python_api/sphinx_doc_gen.py
+++ b/doc/python_api/sphinx_doc_gen.py
@@ -1565,9 +1565,9 @@ def pyrna2sphinx(basepath):
 
     # operators
     def write_ops():
-        API_BASEURL = "https://developer.blender.org/diffusion/B/browse/master/release/scripts/ "
-        API_BASEURL_ADDON = "https://developer.blender.org/diffusion/BA/"
-        API_BASEURL_ADDON_CONTRIB = "https://developer.blender.org/diffusion/BAC/"
+        API_BASEURL = "https://developer.blender.org/diffusion/B/browse/master/release/scripts "
+        API_BASEURL_ADDON = "https://developer.blender.org/diffusion/BA"
+        API_BASEURL_ADDON_CONTRIB = "https://developer.blender.org/diffusion/BAC"
 
         op_modules = {}
         for op in ops.values():
@@ -1659,8 +1659,11 @@ def write_sphinx_conf_py(basepath):
     fw("\n")
 
     # needed for latex, pdf gen
+    fw("latex_elements = {\n")
+    fw("  'papersize': 'a4paper',\n")
+    fw("}\n\n")
+
     fw("latex_documents = [ ('contents', 'contents.tex', 'Blender Index', 'Blender Foundation', 'manual'), ]\n")
-    fw("latex_paper_size = 'a4paper'\n")
     file.close()
 
 
diff --git a/intern/cycles/blender/blender_mesh.cpp b/intern/cycles/blender/blender_mesh.cpp
index fab03c7659b..66893d4d668 100644
--- a/intern/cycles/blender/blender_mesh.cpp
+++ b/intern/cycles/blender/blender_mesh.cpp
@@ -597,8 +597,8 @@ static void create_mesh(Scene *scene,
                         Mesh *mesh,
                         BL::Mesh& b_mesh,
                         const vector<Shader*>& used_shaders,
-                        bool subdivision=false,
-                        bool subdivide_uvs=true)
+                        bool subdivision = false,
+                        bool subdivide_uvs = true)
 {
 	/* count vertices and faces */
 	int numverts = b_mesh.vertices.length();
@@ -671,28 +671,10 @@ static void create_mesh(Scene *scene,
 			int shader = clamp(f->material_index(), 0, used_shaders.size()-1);
 			bool smooth = f->use_smooth() || use_loop_normals;
 
-			/* split vertices if normal is different
+			/* Create triangles.
 			 *
-			 * note all vertex attributes must have been set here so we can split
-			 * and copy attributes in split_vertex without remapping later */
-			if(use_loop_normals) {
-				BL::Array<float, 12> loop_normals = f->split_normals();
-
-				for(int i = 0; i < n; i++) {
-					float3 loop_N = make_float3(loop_normals[i * 3], loop_normals[i * 3 + 1], loop_normals[i * 3 + 2]);
-
-					if(N[vi[i]] != loop_N) {
-						int new_vi = mesh->split_vertex(vi[i]);
-
-						/* set new normal and vertex index */
-						N = attr_N->data_float3();
-						N[new_vi] = loop_N;
-						vi[i] = new_vi;
-					}
-				}
-			}
-
-			/* create triangles */
+			 * NOTE: Autosmooth is already taken care about.
+			 */
 			if(n == 4) {
 				if(is_zero(cross(mesh->verts[vi[1]] - mesh->verts[vi[0]], mesh->verts[vi[2]] - mesh->verts[vi[0]])) ||
 				   is_zero(cross(mesh->verts[vi[2]] - mesh->verts[vi[0]], mesh->verts[vi[3]] - mesh->verts[vi[0]])))
@@ -724,24 +706,8 @@ static void create_mesh(Scene *scene,
 
 			vi.reserve(n);
 			for(int i = 0; i < n; i++) {
+				/* NOTE: Autosmooth is already taken care about. */
 				vi[i] = b_mesh.loops[p->loop_start() + i].vertex_index();
-
-				/* split vertices if normal is different
-				 *
-				 * note all vertex attributes must have been set here so we can split
-				 * and copy attributes in split_vertex without remapping later */
-				if(use_loop_normals) {
-					float3 loop_N = get_float3(b_mesh.loops[p->loop_start() + i].normal());
-
-					if(N[vi[i]] != loop_N) {
-						int new_vi = mesh->split_vertex(vi[i]);
-
-						/* set new normal and vertex index */
-						N = attr_N->data_float3();
-						N[new_vi] = loop_N;
-						vi[i] = new_vi;
-					}
-				}
 			}
 
 			/* create subd faces */
@@ -961,7 +927,13 @@ Mesh *BlenderSync::sync_mesh(BL::Object& b_ob,
 
 		mesh->subdivision_type = object_subdivision_type(b_ob, preview, experimental);
 
-		BL::Mesh b_mesh = object_to_mesh(b_data, b_ob, b_scene, true, !preview, need_undeformed, mesh->subdivision_type);
+		BL::Mesh b_mesh = object_to_mesh(b_data,
+		                                 b_ob,
+		                                 b_scene,
+		                                 true,
+		                                 !preview,
+		                                 need_undeformed,
+		                                 mesh->subdivision_type);
 
 		if(b_mesh) {
 			if(render_layer.use_surfaces && !hide_tris) {
@@ -1086,7 +1058,13 @@ void BlenderSync::sync_mesh_motion(BL::Object& b_ob,
 
 	if(ccl::BKE_object_is_deform_modified(b_ob, b_scene, preview)) {
 		/* get derived mesh */
-		b_mesh = object_to_mesh(b_data, b_ob, b_scene, true, !preview, false, false);
+		b_mesh = object_to_mesh(b_data,
+		                        b_ob,
+		                        b_scene,
+		                        true,
+		                        !preview,
+		                        false,
+		                        Mesh::SUBDIVISION_NONE);
 	}
 
 	if(!b_mesh) {
@@ -1157,10 +1135,12 @@ void BlenderSync::sync_mesh_motion(BL::Object& b_ob,
 			{
 				/* no motion, remove attributes again */
 				if(b_mesh.vertices.length() != numverts) {
-					VLOG(1) << "Topology differs, disabling motion blur.";
+					VLOG(1) << "Topology differs, disabling motion blur for object "
+					        << b_ob.name();
 				}
 				else {
-					VLOG(1) << "No actual deformation motion for object " << b_ob.name();
+					VLOG(1) << "No actual deformation motion for object "
+					        << b_ob.name();
 				}
 				mesh->attributes.remove(ATTR_STD_MOTION_VERTEX_POSITION);
 				if(attr_mN)
diff --git a/intern/cycles/blender/blender_session.cpp b/intern/cycles/blender/blender_session.cpp
index 2982c7b2868..4f87a54adfc 100644
--- a/intern/cycles/blender/blender_session.cpp
+++ b/intern/cycles/blender/blender_session.cpp
@@ -577,7 +577,7 @@ static void populate_bake_data(BakeData *data, const
 	BL::BakePixel bp = pixel_array;
 
 	int i;
-	for(i=0; i < num_pixels; i++) {
+	for(i = 0; i < num_pixels; i++) {
 		if(bp.object_id() == object_id) {
 			data->set(i, bp.primitive_id(), bp.uv(), bp.du_dx(), bp.du_dy(), bp.dv_dx(), bp.dv_dy());
 		} else {
diff --git a/intern/cycles/blender/blender_util.h b/intern/cycles/blender/blender_util.h
index de9ab2d63d3..91af27d64a3 100644
--- a/intern/cycles/blender/blender_util.h
+++ b/intern/cycles/blender/blender_util.h
@@ -65,12 +65,12 @@ static inline BL::Mesh object_to_mesh(BL::BlendData& data,
                                       bool apply_modifiers,
                                       bool render,
                                       bool calc_undeformed,
-                                      bool subdivision)
+                                      Mesh::SubdivisionType subdivision_type)
 {
 	bool subsurf_mod_show_render;
 	bool subsurf_mod_show_viewport;
 
-	if(subdivision) {
+	if(subdivision_type != Mesh::SUBDIVISION_NONE) {
 		BL::Modifier subsurf_mod = object.modifiers[object.modifiers.length()-1];
 
 		subsurf_mod_show_render = subsurf_mod.show_render();
@@ -82,7 +82,7 @@ static inline BL::Mesh object_to_mesh(BL::BlendData& data,
 
 	BL::Mesh me = data.meshes.new_from_object(scene, object, apply_modifiers, (render)? 2: 1, false, calc_undeformed);
 
-	if(subdivision) {
+	if(subdivision_type != Mesh::SUBDIVISION_NONE) {
 		BL::Modifier subsurf_mod = object.modifiers[object.modifiers.length()-1];
 
 		subsurf_mod.show_render(subsurf_mod_show_render);
@@ -91,9 +91,14 @@ static inline BL::Mesh object_to_mesh(BL::BlendData& data,
 
 	if((bool)me) {
 		if(me.use_auto_smooth()) {
-			me.calc_normals_split();
+			if(subdivision_type == Mesh::SUBDIVISION_CATMULL_CLARK) {
+				me.calc_normals_split();
+			}
+			else {
+				me.split_faces();
+			}
 		}
-		if(!subdivision) {
+		if(subdivision_type == Mesh::SUBDIVISION_NONE) {
 			me.calc_tessface(true);
 		}
 	}
diff --git a/intern/smoke/intern/VEC3.h b/intern/smoke/intern/VEC3.h
index dafe5e52dbd..ffc7da88138 100644
--- a/intern/smoke/intern/VEC3.h
+++ b/intern/smoke/intern/VEC3.h
@@ -943,14 +943,16 @@ operator<<( std::ostream& os, const BasicVector::Vector3Dim<Scalar>& i )
 {
 #if 0
 	char buf[256];
-#if _WIN32
-  sprintf(buf,globVecFormatStr, (double)i[0],(double)i[1],(double)i[2]);
-#else
-  snprintf(buf,256,globVecFormatStr, (double)i[0],(double)i[1],(double)i[2]);
-#endif
+#  if _WIN32
+	sprintf(buf,globVecFormatStr, (double)i[0],(double)i[1],(double)i[2]);
+#  else
+	snprintf(buf,256,globVecFormatStr, (double)i[0],(double)i[1],(double)i[2]);
+#  endif
 	os << std::string(buf); 
+#else
+	(void)i;  /* Ignored. */
 #endif
-  return os;
+	return os;
 }
 
 
diff --git a/release/scripts/startup/bl_operators/image.py b/release/scripts/startup/bl_operators/image.py
index f00f5d97c5e..d3460383fe7 100644
--- a/release/scripts/startup/bl_operators/image.py
+++ b/release/scripts/startup/bl_operators/image.py
@@ -82,8 +82,8 @@ class EditExternally(Operator):
             import traceback
             traceback.print_exc()
             self.report({'ERROR'},
-                        "Image editor not found, "
-                        "please specify in User Preferences > File")
+                        "Image editor could not be launched, please ensure that "
+                        "the path in User Preferences > File is valid, and Blender has rights to launch it")
 
             return {'CANCELLED'}
 
diff --git a/release/scripts/startup/bl_operators/object_quick_effects.py b/release/scripts/startup/bl_operators/object_quick_effects.py
index cdab380bb9c..ef10e279bb4 100644
--- a/release/scripts/startup/bl_operators/object_quick_effects.py
+++ b/release/scripts/startup/bl_operators/object_quick_effects.py
@@ -210,8 +210,9 @@ class QuickExplode(Operator):
 
             settings = obj.particle_systems[-1].settings
             settings.count = self.amount
-            settings.frame_start = self.frame_start
+            # first set frame end, to prevent frame start clamping
             settings.frame_end = self.frame_end - self.frame_duration
+            settings.frame_start = self.frame_start
             settings.lifetime = self.frame_duration
             settings.normal_factor = self.velocity
             settings.render_type = 'NONE'
diff --git a/release/scripts/startup/bl_ui/properties_game.py b/release/scripts/startup/bl_ui/properties_game.py
index 386ad254892..98b7a76e541 100644
--- a/release/scripts/startup/bl_ui/properties_game.py
+++ b/release/scripts/startup/bl_ui/properties_game.py
@@ -289,7 +289,6 @@ class RENDER_PT_embedded(RenderButtonsPanel, Panel):
 
         row = layout.row()
         row.operator("view3d.game_start", text="Start")
-        row.label()
         row = layout.row()
         row.label(text="Resolution:")
         row = layout.row(align=True)
@@ -310,8 +309,6 @@ class RENDER_PT_game_player(RenderButtonsPanel, Panel):
 
         row = layout.row()
         row.operator("wm.blenderplayer_start", text="Start")
-        row.label()
-
         row = layout.row()
         row.label(text="Resolution:")
         row = layout.row(align=True)
diff --git a/release/scripts/startup/bl_ui/properties_grease_pencil_common.py b/release/scripts/startup/bl_ui/properties_grease_pencil_common.py
index 08e07b8ed93..f8ee7c9a851 100644
--- a/release/scripts/startup/bl_ui/properties_grease_pencil_common.py
+++ b/release/scripts/startup/bl_ui/properties_grease_pencil_common.py
@@ -946,7 +946,10 @@ class GreasePencilDataPanel:
 
         row = col.row()
         row.prop(gpl, "use_onion_skinning")
-        row.prop(gpl, "use_ghost_custom_colors", text="", icon='COLOR')
+        sub = row.row(align=True)
+        icon = 'RESTRICT_RENDER_OFF' if gpl.use_ghosts_always else 'RESTRICT_RENDER_ON'
+        sub.prop(gpl, "use_ghosts_always", text="", icon=icon)
+        sub.prop(gpl, "use_ghost_custom_colors", text="", icon='COLOR')
 
         split = col.split(percentage=0.5)
         split.active = gpl.use_onion_skinning
diff --git a/release/scripts/startup/bl_ui/properties_particle.py b/release/scripts/startup/bl_ui/properties_particle.py
index 4e2666d7e40..29fc56c3fad 100644
--- a/release/scripts/startup/bl_ui/properties_particle.py
+++ b/release/scripts/startup/bl_ui/properties_particle.py
@@ -752,8 +752,8 @@ class PARTICLE_PT_physics(ParticleButtonsPanel, Panel):
             subsub.operator("particle.target_remove", icon='ZOOMOUT', text="")
             sub = col.row()
             subsub = sub.column(align=True)
-            subsub.operator("particle.target_move_up", icon='MOVE_UP_VEC', text="")
-            subsub.operator("particle.target_move_down", icon='MOVE_DOWN_VEC', text="")
+            subsub.operator("particle.target_move_up", icon='TRIA_UP', text="")
+            subsub.operator("particle.target_move_down", icon='TRIA_DOWN', text="")
 
             key = psys.active_particle_target
             if key:
@@ -816,8 +816,8 @@ class PARTICLE_PT_boidbrain(ParticleButtonsPanel, Panel):
         #sub.operator("boid.state_add", icon='ZOOMIN', text="")
         #sub.operator("boid.state_del", icon='ZOOMOUT', text="")
         #sub = row.row(align=True)
-        #sub.operator("boid.state_move_up", icon='MOVE_UP_VEC', text="")
-        #sub.operator("boid.state_move_down", icon='MOVE_DOWN_VEC', text="")
+        #sub.operator("boid.state_move_up", icon='TRIA_UP', text="")
+        #sub.operator("boid.state_move_down", icon='TRIA_DOWN', text="")
 
         state = boids.active_boid_state
 
@@ -840,8 +840,8 @@ class PARTICLE_PT_boidbrain(ParticleButtonsPanel, Panel):
         subsub.operator("boid.rule_del", icon='ZOOMOUT', text="")
         sub = col.row()
         subsub = sub.column(align=True)
-        subsub.operator("boid.rule_move_up", icon='MOVE_UP_VEC', text="")
-        subsub.operator("boid.rule_move_down", icon='MOVE_DOWN_VEC', text="")
+        subsub.operator("boid.rule_move_up", icon='TRIA_UP', text="")
+        subsub.operator("boid.rule_move_down", icon='TRIA_DOWN', text="")
 
         rule = state.active_boid_rule
 
@@ -849,8 +849,8 @@ class PARTICLE_PT_boidbrain(ParticleButtonsPanel, Panel):
             row = layout.row()
             row.prop(rule, "name", text="")
             #somebody make nice icons for boids here please! -jahka
-            row.prop(rule, "use_in_air", icon='MOVE_UP_VEC', text="")
-            row.prop(rule, "use_on_land", icon='MOVE_DOWN_VEC', text="")
+            row.prop(rule, "use_in_air", icon='TRIA_UP', text="")
+            row.prop(rule, "use_on_land", icon='TRIA_DOWN', text="")
 
             row = layout.row()
 
@@ -1009,8 +1009,8 @@ class PARTICLE_PT_render(ParticleButtonsPanel, Panel):
                 subsub = sub.column(align=True)
                 subsub.operator("particle.dupliob_copy", icon='ZOOMIN', text="")
                 subsub.operator("particle.dupliob_remove", icon='ZOOMOUT', text="")
-                subsub.operator("particle.dupliob_move_up", icon='MOVE_UP_VEC', text="")
-                subsub.operator("particle.dupliob_move_down", icon='MOVE_DOWN_VEC', text="")
+                subsub.operator("particle.dupliob_move_up", icon='TRIA_UP', text="")
+                subsub.operator("particle.dupliob_move_down", icon='TRIA_DOWN', text="")
 
                 weight = part.active_dupliweight
                 if weight:
diff --git a/release/scripts/startup/bl_ui/space_userpref.py b/release/scripts/startup/bl_ui/space_userpref.py
index e5b6a94c1ab..075a6f870fa 100644
--- a/release/scripts/startup/bl_ui/space_userpref.py
+++ b/release/scripts/startup/bl_ui/space_userpref.py
@@ -1180,11 +1180,18 @@ class USERPREF_PT_input(Panel):
             col.separator()
             col.label(text="NDOF Device:")
             sub = col.column(align=True)
-            sub.prop(inputs, "ndof_sensitivity", text="NDOF Sensitivity")
-            sub.prop(inputs, "ndof_orbit_sensitivity", text="NDOF Orbit Sensitivity")
-            sub.prop(inputs, "ndof_deadzone", text="NDOF Deadzone")
+            sub.prop(inputs, "ndof_sensitivity", text="Pan Sensitivity")
+            sub.prop(inputs, "ndof_orbit_sensitivity", text="Orbit Sensitivity")
+            sub.prop(inputs, "ndof_deadzone", text="Deadzone")
+
+            sub.separator()
+            col.label(text="Navigation Style:")
             sub = col.column(align=True)
             sub.row().prop(inputs, "ndof_view_navigate_method", expand=True)
+
+            sub.separator()
+            col.label(text="Rotation Style:")
+            sub = col.column(align=True)
             sub.row().prop(inputs, "ndof_view_rotate_method", expand=True)
 
         row.separator()
diff --git a/release/scripts/startup/bl_ui/space_view3d.py b/release/scripts/startup/bl_ui/space_view3d.py
index 55fa2c28011..5e936076d0e 100644
--- a/release/scripts/startup/bl_ui/space_view3d.py
+++ b/release/scripts/startup/bl_ui/space_view3d.py
@@ -2528,7 +2528,14 @@ class VIEW3D_MT_edit_mesh_edges(Menu):
         layout.operator("mesh.bevel").vertex_only = False
         layout.operator("mesh.edge_split")
         layout.operator("mesh.bridge_edge_loops")
+
+        layout.separator()
+
         layout.operator("transform.edge_slide")
+        layout.operator("mesh.loop_multi_select", text="Edge Loops").ring = False
+        layout.operator("mesh.loop_multi_select", text="Edge Rings").ring = True
+        layout.operator("mesh.loop_to_region")
+        layout.operator("mesh.region_to_loop")
 
 
 class VIEW3D_MT_edit_mesh_faces(Menu):
diff --git a/release/scripts/templates_py/addon_add_object.py b/release/scripts/templates_py/addon_add_object.py
index 8e57d7ef8f8..d294838d3a2 100644
--- a/release/scripts/templates_py/addon_add_object.py
+++ b/release/scripts/templates_py/addon_add_object.py
@@ -69,9 +69,9 @@ def add_object_button(self, context):
 
 # This allows you to right click on a button and link to the manual
 def add_object_manual_map():
-    url_manual_prefix = "http://wiki.blender.org/index.php/Doc:2.6/Manual/"
+    url_manual_prefix = "https://www.blender.org/manual/"
     url_manual_mapping = (
-        ("bpy.ops.mesh.add_object", "Modeling/Objects"),
+        ("bpy.ops.mesh.add_object", "editors/3dview/object"),
         )
     return url_manual_prefix, url_manual_mapping
 
diff --git a/source/blender/blenkernel/BKE_sound.h b/source/blender/blenkernel/BKE_sound.h
index 28b15b2a310..a5c626e74d7 100644
--- a/source/blender/blenkernel/BKE_sound.h
+++ b/source/blender/blenkernel/BKE_sound.h
@@ -90,6 +90,8 @@ void BKE_sound_create_scene(struct Scene *scene);
 
 void BKE_sound_destroy_scene(struct Scene *scene);
 
+void BKE_sound_reset_scene_specs(struct Scene *scene);
+
 void BKE_sound_mute_scene(struct Scene *scene, int muted);
 
 void BKE_sound_update_fps(struct Scene *scene);
diff --git a/source/blender/blenkernel/intern/collision.c b/source/blender/blenkernel/intern/collision.c
index 18ca1407ba0..ee25be36855 100644
--- a/source/blender/blenkernel/intern/collision.c
+++ b/source/blender/blenkernel/intern/collision.c
@@ -1014,7 +1014,7 @@ static bool cloth_points_collision_response_static(ClothModifierData *clmd, Coll
 }
 
 BLI_INLINE bool cloth_point_face_collision_params(const float p1[3], const float p2[3], const float v0[3], const float v1[3], const float v2[3],
-                                                  float r_nor[3], float *r_lambda, float r_w[4])
+                                                  float r_nor[3], float *r_lambda, float r_w[3])
 {
 	float edge1[3], edge2[3], p2face[3], p1p2[3], v0p2[3];
 	float nor_v0p2, nor_p1p2;
@@ -1026,7 +1026,7 @@ BLI_INLINE bool cloth_point_face_collision_params(const float p1[3], const float
 	
 	nor_v0p2 = dot_v3v3(v0p2, r_nor);
 	madd_v3_v3v3fl(p2face, p2, r_nor, -nor_v0p2);
-	interp_weights_face_v3(r_w, v0, v1, v2, NULL, p2face);
+	interp_weights_tri_v3(r_w, v0, v1, v2, p2face);
 	
 	sub_v3_v3v3(p1p2, p2, p1);
 	sub_v3_v3v3(v0p2, p2, v0);
@@ -1085,7 +1085,7 @@ static CollPair *cloth_point_collpair(
 	const float *co1 = mverts[bp1].co, *co2 = mverts[bp2].co, *co3 = mverts[bp3].co;
 	float lambda /*, distance1 */, distance2;
 	float facenor[3], v1p1[3], v1p2[3];
-	float w[4];
+	float w[3];
 
 	if (!cloth_point_face_collision_params(p1, p2, co1, co2, co3, facenor, &lambda, w))
 		return collpair;
diff --git a/source/blender/blenkernel/intern/dynamicpaint.c b/source/blender/blenkernel/intern/dynamicpaint.c
index 66070923153..1d198e36e05 100644
--- a/source/blender/blenkernel/intern/dynamicpaint.c
+++ b/source/blender/blenkernel/intern/dynamicpaint.c
@@ -3739,7 +3739,7 @@ static void dynamic_paint_paint_mesh_cell_point_cb_ex(
 
 		/* velocity brush, only do on main sample */
 		if (brush->flags & MOD_DPAINT_USES_VELOCITY && ss == 0 && brushVelocity) {
-			float weights[4];
+			float weights[3];
 			float brushPointVelocity[3];
 			float velocity[3];
 
@@ -3748,7 +3748,7 @@ static void dynamic_paint_paint_mesh_cell_point_cb_ex(
 			const int v3 = mloop[mlooptri[hitTri].tri[2]].v;
 
 			/* calculate barycentric weights for hit point */
-			interp_weights_face_v3(weights, mvert[v1].co, mvert[v2].co, mvert[v3].co, NULL, hitCoord);
+			interp_weights_tri_v3(weights, mvert[v1].co, mvert[v2].co, mvert[v3].co, hitCoord);
 
 			/* simple check based on brush surface velocity,
 			 *  todo: perhaps implement something that handles volume movement as well */
@@ -4737,7 +4737,7 @@ static void dynamic_paint_effect_spread_cb(void *userdata, const int index)
 		CLAMP(w_factor, 0.0f, 1.0f);
 
 		/* mix new wetness and color */
-		pPoint->wetness = (1.0f - w_factor) * pPoint->wetness + w_factor * pPoint_prev->wetness;
+		pPoint->wetness = pPoint->wetness + w_factor * (pPoint_prev->wetness - pPoint->wetness);
 		pPoint->e_color[3] = mixColors(pPoint->e_color, pPoint->e_color[3],
 		                               pPoint_prev->e_color, pPoint_prev->e_color[3], w_factor);
 	}
diff --git a/source/blender/blenkernel/intern/library.c b/source/blender/blenkernel/intern/library.c
index 65f37d0a5b1..64535f229a9 100644
--- a/source/blender/blenkernel/intern/library.c
+++ b/source/blender/blenkernel/intern/library.c
@@ -1431,14 +1431,18 @@ static bool check_for_dupid(ListBase *lb, ID *id, char *name)
 
 		/* if new name will be too long, truncate it */
 		if (nr > 999 && left_len > (MAX_ID_NAME - 8)) {  /* assumption: won't go beyond 9999 */
-			left[MAX_ID_NAME - 8] = 0;
+			left[MAX_ID_NAME - 8] = '\0';
 			left_len = MAX_ID_NAME - 8;
 		}
 		else if (left_len > (MAX_ID_NAME - 7)) {
-			left[MAX_ID_NAME - 7] = 0;
+			left[MAX_ID_NAME - 7] = '\0';
 			left_len = MAX_ID_NAME - 7;
 		}
 
+		/* Code above may have generated invalid utf-8 string, due to raw truncation.
+		 * Ensure we get a valid one now! */
+		left_len -= BLI_utf8_invalid_strip(left, left_len);
+
 		for (idtest = lb->first; idtest; idtest = idtest->next) {
 			int nrtest;
 			if ( (id != idtest) &&
diff --git a/source/blender/blenkernel/intern/library_remap.c b/source/blender/blenkernel/intern/library_remap.c
index 4f1f6d963ed..d7d566a9ec0 100644
--- a/source/blender/blenkernel/intern/library_remap.c
+++ b/source/blender/blenkernel/intern/library_remap.c
@@ -522,8 +522,7 @@ void BKE_libblock_remap_locked(
 	 * been incremented for that, we have to decrease once more its user count... unless we had to skip
 	 * some 'user_one' cases. */
 	if ((old_id->tag & LIB_TAG_EXTRAUSER_SET) && !(id_remap_data.status & ID_REMAP_IS_USER_ONE_SKIPPED)) {
-		id_us_min(old_id);
-		old_id->tag &= ~LIB_TAG_EXTRAUSER_SET;
+		id_us_clear_real(old_id);
 	}
 
 	BLI_assert(old_id->us - skipped_refcounted >= 0);
@@ -563,8 +562,14 @@ void BKE_libblock_remap_locked(
 		default:
 			break;
 	}
+
 	/* Node trees may virtually use any kind of data-block... */
+	/* XXX Yuck!!!! nodetree update can do pretty much any thing when talking about py nodes,
+	 *     including creating new data-blocks (see T50385), so we need to unlock main here. :(
+	 *     Why can't we have re-entrent locks? */
+	BKE_main_unlock(bmain);
 	libblock_remap_data_postprocess_nodetree_update(bmain, new_id);
+	BKE_main_lock(bmain);
 
 	/* Full rebuild of DAG! */
 	DAG_relations_tag_update(bmain);
@@ -883,9 +888,10 @@ void BKE_libblock_free_us(Main *bmain, void *idv)      /* test users */
 	 *     Since only 'user_one' usage of objects is groups, and only 'real user' usage of objects is scenes,
 	 *     removing that 'user_one' tag when there is no more real (scene) users of an object ensures it gets
 	 *     fully unlinked.
+	 *     But only for local objects, not linked ones!
 	 *     Otherwise, there is no real way to get rid of an object anymore - better handling of this is TODO.
 	 */
-	if ((GS(id->name) == ID_OB) && (id->us == 1)) {
+	if ((GS(id->name) == ID_OB) && (id->us == 1) && (id->lib == NULL)) {
 		id_us_clear_real(id);
 	}
 
diff --git a/source/blender/blenkernel/intern/mesh.c b/source/blender/blenkernel/intern/mesh.c
index d21f43ac484..af02e02b017 100644
--- a/source/blender/blenkernel/intern/mesh.c
+++ b/source/blender/blenkernel/intern/mesh.c
@@ -2346,6 +2346,11 @@ Mesh *BKE_mesh_new_from_object(
 
 				tmpmesh = BKE_mesh_add(bmain, "Mesh");
 				DM_to_mesh(dm, tmpmesh, ob, mask, true);
+
+				/* Copy autosmooth settings from original mesh. */
+				Mesh *me = (Mesh *)ob->data;
+				tmpmesh->flag |= (me->flag & ME_AUTOSMOOTH);
+				tmpmesh->smoothresh = me->smoothresh;
 			}
 
 			/* BKE_mesh_add/copy gives us a user count we don't need */
diff --git a/source/blender/blenkernel/intern/mesh_evaluate.c b/source/blender/blenkernel/intern/mesh_evaluate.c
index a3fe73e4b11..f9eba118383 100644
--- a/source/blender/blenkernel/intern/mesh_evaluate.c
+++ b/source/blender/blenkernel/intern/mesh_evaluate.c
@@ -1909,19 +1909,19 @@ void BKE_mesh_calc_poly_center(
         const MVert *mvarray, float r_cent[3])
 {
 	if (mpoly->totloop == 3) {
-		cent_tri_v3(r_cent,
-		            mvarray[loopstart[0].v].co,
-		            mvarray[loopstart[1].v].co,
-		            mvarray[loopstart[2].v].co
-		            );
+		mid_v3_v3v3v3(r_cent,
+		              mvarray[loopstart[0].v].co,
+		              mvarray[loopstart[1].v].co,
+		              mvarray[loopstart[2].v].co
+		              );
 	}
 	else if (mpoly->totloop == 4) {
-		cent_quad_v3(r_cent,
-		             mvarray[loopstart[0].v].co,
-		             mvarray[loopstart[1].v].co,
-		             mvarray[loopstart[2].v].co,
-		             mvarray[loopstart[3].v].co
-		             );
+		mid_v3_v3v3v3v3(r_cent,
+		                mvarray[loopstart[0].v].co,
+		                mvarray[loopstart[1].v].co,
+		                mvarray[loopstart[2].v].co,
+		                mvarray[loopstart[3].v].co
+		                );
 	}
 	else {
 		mesh_calc_ngon_center(mpoly, loopstart, mvarray, r_cent);
@@ -1978,7 +1978,7 @@ static float mesh_calc_poly_planar_area_centroid(
 		tri_area = area_tri_signed_v3(v1, v2, v3, normal);
 		total_area += tri_area;
 
-		cent_tri_v3(tri_cent, v1, v2, v3);
+		mid_v3_v3v3v3(tri_cent, v1, v2, v3);
 		madd_v3_v3fl(r_cent, tri_cent, tri_area);
 
 		copy_v3_v3(v2, v3);
diff --git a/source/blender/blenkernel/intern/object.c b/source/blender/blenkernel/intern/object.c
index c6666ec5ced..e93bfcdda83 100644
--- a/source/blender/blenkernel/intern/object.c
+++ b/source/blender/blenkernel/intern/object.c
@@ -246,6 +246,10 @@ bool BKE_object_support_modifier_type_check(Object *ob, int modifier_type)
 
 	mti = modifierType_getInfo(modifier_type);
 
+	/* only geometry objects should be able to get modifiers [#25291] */
+	if (!ELEM(ob->type, OB_MESH, OB_CURVE, OB_SURF, OB_FONT, OB_LATTICE)) {
+		return false;
+	}
 
 	if (ob->type == OB_LATTICE && (mti->flags & eModifierTypeFlag_AcceptsLattice) == 0) {
 		return false;
diff --git a/source/blender/blenkernel/intern/smoke.c b/source/blender/blenkernel/intern/smoke.c
index e8970d416e9..d0ef5cfc092 100644
--- a/source/blender/blenkernel/intern/smoke.c
+++ b/source/blender/blenkernel/intern/smoke.c
@@ -758,15 +758,14 @@ static void obstacles_from_derivedmesh_task_cb(void *userdata, const int z)
 			/* find the nearest point on the mesh */
 			if (BLI_bvhtree_find_nearest(data->tree->tree, ray_start, &nearest, data->tree->nearest_callback, data->tree) != -1) {
 				const MLoopTri *lt = &data->looptri[nearest.index];
-				float weights[4];
+				float weights[3];
 				int v1, v2, v3;
 
 				/* calculate barycentric weights for nearest point */
 				v1 = data->mloop[lt->tri[0]].v;
 				v2 = data->mloop[lt->tri[1]].v;
 				v3 = data->mloop[lt->tri[2]].v;
-				interp_weights_face_v3(
-				            weights, data->mvert[v1].co, data->mvert[v2].co, data->mvert[v3].co, NULL, nearest.co);
+				interp_weights_tri_v3(weights, data->mvert[v1].co, data->mvert[v2].co, data->mvert[v3].co, nearest.co);
 
 				// DG TODO
 				if (data->has_velocity)
@@ -1454,7 +1453,7 @@ static void sample_derivedmesh(
 
 	/* find the nearest point on the mesh */
 	if (BLI_bvhtree_find_nearest(treeData->tree, ray_start, &nearest, treeData->nearest_callback, treeData) != -1) {
-		float weights[4];
+		float weights[3];
 		int v1, v2, v3, f_index = nearest.index;
 		float n1[3], n2[3], n3[3], hit_normal[3];
 
@@ -1471,7 +1470,7 @@ static void sample_derivedmesh(
 		v1 = mloop[mlooptri[f_index].tri[0]].v;
 		v2 = mloop[mlooptri[f_index].tri[1]].v;
 		v3 = mloop[mlooptri[f_index].tri[2]].v;
-		interp_weights_face_v3(weights, mvert[v1].co, mvert[v2].co, mvert[v3].co, NULL, nearest.co);
+		interp_weights_tri_v3(weights, mvert[v1].co, mvert[v2].co, mvert[v3].co, nearest.co);
 
 		if (sfs->flags & MOD_SMOKE_FLOW_INITVELOCITY && velocity_map) {
 			/* apply normal directional velocity */
diff --git a/source/blender/blenkernel/intern/sound.c b/source/blender/blenkernel/intern/sound.c
index f20885b1e8f..22288127119 100644
--- a/source/blender/blenkernel/intern/sound.c
+++ b/source/blender/blenkernel/intern/sound.c
@@ -167,6 +167,10 @@ static const char *force_device = NULL;
 #ifdef WITH_JACK
 static void sound_sync_callback(void *data, int mode, float time)
 {
+	// Ugly: Blender doesn't like it when the animation is played back during rendering
+	if (G.is_rendering)
+		return;
+
 	struct Main *bmain = (struct Main *)data;
 	struct Scene *scene;
 
@@ -450,6 +454,16 @@ void BKE_sound_destroy_scene(struct Scene *scene)
 		AUD_destroySet(scene->speaker_handles);
 }
 
+void BKE_sound_reset_scene_specs(struct Scene *scene)
+{
+	AUD_Specs specs;
+
+	specs.channels = AUD_Device_getChannels(sound_device);
+	specs.rate = AUD_Device_getRate(sound_device);
+
+	AUD_Sequence_setSpecs(scene->sound_scene, specs);
+}
+
 void BKE_sound_mute_scene(struct Scene *scene, int muted)
 {
 	if (scene->sound_scene)
@@ -576,15 +590,10 @@ void BKE_sound_update_sequencer(struct Main *main, bSound *sound)
 
 static void sound_start_play_scene(struct Scene *scene)
 {
-	AUD_Specs specs;
-
 	if (scene->playback_handle)
 		AUD_Handle_stop(scene->playback_handle);
 
-	specs.channels = AUD_Device_getChannels(sound_device);
-	specs.rate = AUD_Device_getRate(sound_device);
-
-	AUD_Sequence_setSpecs(scene->sound_scene, specs);
+	BKE_sound_reset_scene_specs(scene);
 
 	if ((scene->playback_handle = AUD_Device_play(sound_device, scene->sound_scene, 1)))
 		AUD_Handle_setLoopCount(scene->playback_handle, -1);
@@ -693,6 +702,10 @@ void BKE_sound_seek_scene(struct Main *bmain, struct Scene *scene)
 
 float BKE_sound_sync_scene(struct Scene *scene)
 {
+	// Ugly: Blender doesn't like it when the animation is played back during rendering
+	if (G.is_rendering)
+		return NAN_FLT;
+
 	if (scene->playback_handle) {
 		if (scene->audio.flag & AUDIO_SYNC)
 			return AUD_getSynchronizerPosition(scene->playback_handle);
@@ -704,6 +717,10 @@ float BKE_sound_sync_scene(struct Scene *scene)
 
 int BKE_sound_scene_playing(struct Scene *scene)
 {
+	// Ugly: Blender doesn't like it when the animation is played back during rendering
+	if (G.is_rendering)
+		return -1;
+
 	if (scene->audio.flag & AUDIO_SYNC)
 		return AUD_isSynchronizerPlaying();
 	else
@@ -898,6 +915,7 @@ void BKE_sound_delete_cache(struct bSound *UNUSED(sound)) {}
 void BKE_sound_load(struct Main *UNUSED(bmain), struct bSound *UNUSED(sound)) {}
 void BKE_sound_create_scene(struct Scene *UNUSED(scene)) {}
 void BKE_sound_destroy_scene(struct Scene *UNUSED(scene)) {}
+void BKE_sound_reset_scene_specs(struct Scene *UNUSED(scene)) {}
 void BKE_sound_mute_scene(struct Scene *UNUSED(scene), int UNUSED(muted)) {}
 void *BKE_sound_scene_add_scene_sound(struct Scene *UNUSED(scene), struct Sequence *UNUSED(sequence),
                                       int UNUSED(startframe), int UNUSED(endframe), int UNUSED(frameskip)) { return NULL; }
diff --git a/source/blender/blenkernel/intern/text.c b/source/blender/blenkernel/intern/text.c
index 1636042f479..672857e88fe 100644
--- a/source/blender/blenkernel/intern/text.c
+++ b/source/blender/blenkernel/intern/text.c
@@ -410,6 +410,7 @@ Text *BKE_text_load_ex(Main *bmain, const char *file, const char *relpath, const
 	}
 
 	ta = BKE_libblock_alloc(bmain, ID_TXT, BLI_path_basename(filepath_abs));
+	ta->id.us = 0;
 
 	BLI_listbase_clear(&ta->lines);
 	ta->curl = ta->sell = NULL;
diff --git a/source/blender/blenkernel/intern/writeffmpeg.c b/source/blender/blenkernel/intern/writeffmpeg.c
index b0ab6f707fa..9994d479ce7 100644
--- a/source/blender/blenkernel/intern/writeffmpeg.c
+++ b/source/blender/blenkernel/intern/writeffmpeg.c
@@ -444,7 +444,7 @@ static void set_ffmpeg_property_option(AVCodecContext *c, IDProperty *prop, AVDi
 	param = strchr(name, ':');
 
 	if (param) {
-		*param++ = 0;
+		*param++ = '\0';
 	}
 
 	switch (prop->type) {
@@ -1114,7 +1114,7 @@ static void ffmpeg_filepath_get(FFMpegContext *context, char *string, RenderData
 
 	BLI_make_existing_file(string);
 
-	autosplit[0] = 0;
+	autosplit[0] = '\0';
 
 	if ((rd->ffcodecdata.flags & FFMPEG_AUTOSPLIT_OUTPUT) != 0) {
 		if (context) {
@@ -1137,7 +1137,7 @@ static void ffmpeg_filepath_get(FFMpegContext *context, char *string, RenderData
 			strcat(string, *exts);
 		}
 		else {
-			*(string + strlen(string) - strlen(*fe)) = 0;
+			*(string + strlen(string) - strlen(*fe)) = '\0';
 			strcat(string, autosplit);
 			strcat(string, *fe);
 		}
@@ -1267,7 +1267,7 @@ static void end_ffmpeg_impl(FFMpegContext *context, int is_autosplit)
 	if (is_autosplit == false) {
 		if (context->audio_mixdown_device) {
 			AUD_Device_free(context->audio_mixdown_device);
-			context->audio_mixdown_device = 0;
+			context->audio_mixdown_device = NULL;
 		}
 	}
 #endif
@@ -1283,50 +1283,50 @@ static void end_ffmpeg_impl(FFMpegContext *context, int is_autosplit)
 	
 	/* Close the video codec */
 
-	if (context->video_stream && context->video_stream->codec) {
+	if (context->video_stream != NULL && context->video_stream->codec != NULL) {
 		avcodec_close(context->video_stream->codec);
 		PRINT("zero video stream %p\n", context->video_stream);
-		context->video_stream = 0;
+		context->video_stream = NULL;
 	}
 
-	if (context->audio_stream && context->audio_stream->codec) {
+	if (context->audio_stream != NULL && context->audio_stream->codec != NULL) {
 		avcodec_close(context->audio_stream->codec);
-		context->audio_stream = 0;
+		context->audio_stream = NULL;
 	}
 
 	/* free the temp buffer */
-	if (context->current_frame) {
+	if (context->current_frame != NULL) {
 		delete_picture(context->current_frame);
-		context->current_frame = 0;
+		context->current_frame = NULL;
 	}
-	if (context->outfile && context->outfile->oformat) {
+	if (context->outfile != NULL && context->outfile->oformat) {
 		if (!(context->outfile->oformat->flags & AVFMT_NOFILE)) {
 			avio_close(context->outfile->pb);
 		}
 	}
-	if (context->outfile) {
+	if (context->outfile != NULL) {
 		avformat_free_context(context->outfile);
-		context->outfile = 0;
+		context->outfile = NULL;
 	}
-	if (context->audio_input_buffer) {
+	if (context->audio_input_buffer != NULL) {
 		av_free(context->audio_input_buffer);
-		context->audio_input_buffer = 0;
+		context->audio_input_buffer = NULL;
 	}
 #ifndef FFMPEG_HAVE_ENCODE_AUDIO2
-	if (context->audio_output_buffer) {
+	if (context->audio_output_buffer != NULL) {
 		av_free(context->audio_output_buffer);
-		context->audio_output_buffer = 0;
+		context->audio_output_buffer = NULL;
 	}
 #endif
 
-	if (context->audio_deinterleave_buffer) {
+	if (context->audio_deinterleave_buffer != NULL) {
 		av_free(context->audio_deinterleave_buffer);
-		context->audio_deinterleave_buffer = 0;
+		context->audio_deinterleave_buffer = NULL;
 	}
 
-	if (context->img_convert_ctx) {
+	if (context->img_convert_ctx != NULL) {
 		sws_freeContext(context->img_convert_ctx);
-		context->img_convert_ctx = 0;
+		context->img_convert_ctx = NULL;
 	}
 }
 
@@ -1425,8 +1425,8 @@ static IDProperty *BKE_ffmpeg_property_add(RenderData *rd, const char *type, con
 int BKE_ffmpeg_property_add_string(RenderData *rd, const char *type, const char *str)
 {
 	AVCodecContext c;
-	const AVOption *o = 0;
-	const AVOption *p = 0;
+	const AVOption *o = NULL;
+	const AVOption *p = NULL;
 	char name_[128];
 	char *name;
 	char *param;
@@ -1445,7 +1445,7 @@ int BKE_ffmpeg_property_add_string(RenderData *rd, const char *type, const char
 		param = strchr(name, ' ');
 	}
 	if (param) {
-		*param++ = 0;
+		*param++ = '\0';
 		while (*param == ' ') param++;
 	}
 	
diff --git a/source/blender/blenlib/BLI_math_geom.h b/source/blender/blenlib/BLI_math_geom.h
index 514b0300274..d33c2cb3279 100644
--- a/source/blender/blenlib/BLI_math_geom.h
+++ b/source/blender/blenlib/BLI_math_geom.h
@@ -44,9 +44,6 @@ extern "C" {
 
 /********************************** Polygons *********************************/
 
-void cent_tri_v3(float r[3], const float a[3], const float b[3], const float c[3]);
-void cent_quad_v3(float r[3], const float a[3], const float b[3], const float c[3], const float d[3]);
-
 float normal_tri_v3(float r[3], const float a[3], const float b[3], const float c[3]);
 float normal_quad_v3(float r[3], const float a[3], const float b[3], const float c[3], const float d[3]);
 float normal_poly_v3(float r[3], const float verts[][3], unsigned int nr);
@@ -326,10 +323,8 @@ bool clip_segment_v3_plane_n(
         float r_p1[3], float r_p2[3]);
 
 /****************************** Interpolation ********************************/
-
-/* tri or quad, d can be NULL */
-void interp_weights_face_v3(float w[4],
-                            const float a[3], const float b[3], const float c[3], const float d[3], const float p[3]);
+void interp_weights_tri_v3(float w[3], const float a[3], const float b[3], const float c[3], const float p[3]);
+void interp_weights_quad_v3(float w[4], const float a[3], const float b[3], const float c[3], const float d[3], const float p[3]);
 void interp_weights_poly_v3(float w[], float v[][3], const int n, const float co[3]);
 void interp_weights_poly_v2(float w[], float v[][2], const int n, const float co[2]);
 
diff --git a/source/blender/blenlib/BLI_math_vector.h b/source/blender/blenlib/BLI_math_vector.h
index d15fe1a95dc..8e0884ba347 100644
--- a/source/blender/blenlib/BLI_math_vector.h
+++ b/source/blender/blenlib/BLI_math_vector.h
@@ -234,6 +234,7 @@ void mid_v3_v3v3(float r[3], const float a[3], const float b[3]);
 void mid_v2_v2v2(float r[2], const float a[2], const float b[2]);
 void mid_v3_v3v3v3(float v[3], const float v1[3], const float v2[3], const float v3[3]);
 void mid_v3_v3v3v3v3(float v[3], const float v1[3], const float v2[3], const float v3[3], const float v4[3]);
+void mid_v3_v3_array(float r[3], const float (*vec_arr)[3], const unsigned int nbr);
 
 void mid_v3_v3v3_angle_weighted(float r[3], const float a[3], const float b[3]);
 void mid_v3_angle_weighted(float r[3]);
diff --git a/source/blender/blenlib/intern/math_geom.c b/source/blender/blenlib/intern/math_geom.c
index 38947e139ff..74ede1e7559 100644
--- a/source/blender/blenlib/intern/math_geom.c
+++ b/source/blender/blenlib/intern/math_geom.c
@@ -37,20 +37,6 @@
 
 /********************************** Polygons *********************************/
 
-void cent_tri_v3(float cent[3], const float v1[3], const float v2[3], const float v3[3])
-{
-	cent[0] = (v1[0] + v2[0] + v3[0]) / 3.0f;
-	cent[1] = (v1[1] + v2[1] + v3[1]) / 3.0f;
-	cent[2] = (v1[2] + v2[2] + v3[2]) / 3.0f;
-}
-
-void cent_quad_v3(float cent[3], const float v1[3], const float v2[3], const float v3[3], const float v4[3])
-{
-	cent[0] = 0.25f * (v1[0] + v2[0] + v3[0] + v4[0]);
-	cent[1] = 0.25f * (v1[1] + v2[1] + v3[1] + v4[1]);
-	cent[2] = 0.25f * (v1[2] + v2[2] + v3[2] + v4[2]);
-}
-
 void cross_tri_v3(float n[3], const float v1[3], const float v2[3], const float v3[3])
 {
 	float n1[3], n2[3];
@@ -2964,7 +2950,15 @@ static bool barycentric_weights(const float v1[3], const float v2[3], const floa
 	}
 }
 
-void interp_weights_face_v3(float w[4], const float v1[3], const float v2[3], const float v3[3], const float v4[3], const float co[3])
+void interp_weights_tri_v3(float w[3], const float v1[3], const float v2[3], const float v3[3], const float co[3])
+{
+	float n[3];
+
+	normal_tri_v3(n, v1, v2, v3);
+	barycentric_weights(v1, v2, v3, co, n, w);
+}
+
+void interp_weights_quad_v3(float w[4], const float v1[3], const float v2[3], const float v3[3], const float v4[3], const float co[3])
 {
 	float w2[3];
 
@@ -2977,7 +2971,7 @@ void interp_weights_face_v3(float w[4], const float v1[3], const float v2[3], co
 		w[1] = 1.0f;
 	else if (equals_v3v3(co, v3))
 		w[2] = 1.0f;
-	else if (v4 && equals_v3v3(co, v4))
+	else if (equals_v3v3(co, v4))
 		w[3] = 1.0f;
 	else {
 		/* otherwise compute barycentric interpolation weights */
@@ -2985,35 +2979,24 @@ void interp_weights_face_v3(float w[4], const float v1[3], const float v2[3], co
 		bool degenerate;
 
 		sub_v3_v3v3(n1, v1, v3);
-		if (v4) {
-			sub_v3_v3v3(n2, v2, v4);
-		}
-		else {
-			sub_v3_v3v3(n2, v2, v3);
-		}
+		sub_v3_v3v3(n2, v2, v4);
 		cross_v3_v3v3(n, n1, n2);
 
-		/* OpenGL seems to split this way, so we do too */
-		if (v4) {
-			degenerate = barycentric_weights(v1, v2, v4, co, n, w);
-			SWAP(float, w[2], w[3]);
-
-			if (degenerate || (w[0] < 0.0f)) {
-				/* if w[1] is negative, co is on the other side of the v1-v3 edge,
-				 * so we interpolate using the other triangle */
-				degenerate = barycentric_weights(v2, v3, v4, co, n, w2);
-
-				if (!degenerate) {
-					w[0] = 0.0f;
-					w[1] = w2[0];
-					w[2] = w2[1];
-					w[3] = w2[2];
-				}
+		degenerate = barycentric_weights(v1, v2, v4, co, n, w);
+		SWAP(float, w[2], w[3]);
+
+		if (degenerate || (w[0] < 0.0f)) {
+			/* if w[1] is negative, co is on the other side of the v1-v3 edge,
+			 * so we interpolate using the other triangle */
+			degenerate = barycentric_weights(v2, v3, v4, co, n, w2);
+
+			if (!degenerate) {
+				w[0] = 0.0f;
+				w[1] = w2[0];
+				w[2] = w2[1];
+				w[3] = w2[2];
 			}
 		}
-		else {
-			barycentric_weights(v1, v2, v3, co, n, w);
-		}
 	}
 }
 
@@ -3763,6 +3746,9 @@ void interp_barycentric_tri_v3(float data[3][3], float u, float v, float res[3])
 
 /***************************** View & Projection *****************************/
 
+/**
+ * Matches `glOrtho` result.
+ */
 void orthographic_m4(float matrix[4][4], const float left, const float right, const float bottom, const float top,
                      const float nearClip, const float farClip)
 {
@@ -3783,6 +3769,9 @@ void orthographic_m4(float matrix[4][4], const float left, const float right, co
 	matrix[3][2] = -(farClip + nearClip) / Zdelta;
 }
 
+/**
+ * Matches `glFrustum` result.
+ */
 void perspective_m4(float mat[4][4], const float left, const float right, const float bottom, const float top,
                     const float nearClip, const float farClip)
 {
diff --git a/source/blender/blenlib/intern/math_vector.c b/source/blender/blenlib/intern/math_vector.c
index 95d5c9fde87..dfecc3b556a 100644
--- a/source/blender/blenlib/intern/math_vector.c
+++ b/source/blender/blenlib/intern/math_vector.c
@@ -280,6 +280,16 @@ void mid_v3_v3v3v3v3(float v[3], const float v1[3], const float v2[3], const flo
 	v[2] = (v1[2] + v2[2] + v3[2] + v4[2]) / 4.0f;
 }
 
+void mid_v3_v3_array(float r[3], const float (*vec_arr)[3], const unsigned int nbr)
+{
+	const float factor = 1.0f / (float)nbr;
+	zero_v3(r);
+
+	for (unsigned int i = 0; i < nbr; i++) {
+		madd_v3_v3fl(r, vec_arr[i], factor);
+	}
+}
+
 /**
  * Specialized function for calculating normals.
  * fastpath for:
diff --git a/source/blender/blenlib/intern/math_vector_inline.c b/source/blender/blenlib/intern/math_vector_inline.c
index e9fb77f6302..ee5e8651bd3 100644
--- a/source/blender/blenlib/intern/math_vector_inline.c
+++ b/source/blender/blenlib/intern/math_vector_inline.c
@@ -479,7 +479,18 @@ MINLINE void mul_v2_v2_ccw(float r[2], const float mat[2], const float vec[2])
 	r[1] = mat[1] * vec[0] + (+mat[0]) * vec[1];
 }
 
-/* note: could add a matrix inline */
+/**
+ * Convenience function to get the projected depth of a position.
+ * This avoids creating a temporary 4D vector and multiplying it - only for the 4th component.
+ *
+ * Matches logic for:
+ *
+ * \code{.c}
+ * float co_4d[4] = {co[0], co[1], co[2], 1.0};
+ * mul_m4_v4(mat, co_4d);
+ * return co_4d[3];
+ * \endcode
+ */
 MINLINE float mul_project_m4_v3_zfac(float mat[4][4], const float co[3])
 {
 	return (mat[0][3] * co[0]) +
diff --git a/source/blender/blenlib/intern/rct.c b/source/blender/blenlib/intern/rct.c
index 9d5a4630f68..ac73a981b45 100644
--- a/source/blender/blenlib/intern/rct.c
+++ b/source/blender/blenlib/intern/rct.c
@@ -420,20 +420,16 @@ void BLI_rctf_recenter(rctf *rect, float x, float y)
 /* change width & height around the central location */
 void BLI_rcti_resize(rcti *rect, int x, int y)
 {
-	rect->xmin = rect->xmax = BLI_rcti_cent_x(rect);
-	rect->ymin = rect->ymax = BLI_rcti_cent_y(rect);
-	rect->xmin -= x / 2;
-	rect->ymin -= y / 2;
+	rect->xmin = BLI_rcti_cent_x(rect) - (x / 2);
+	rect->ymin = BLI_rcti_cent_y(rect) - (y / 2);
 	rect->xmax = rect->xmin + x;
 	rect->ymax = rect->ymin + y;
 }
 
 void BLI_rctf_resize(rctf *rect, float x, float y)
 {
-	rect->xmin = rect->xmax = BLI_rctf_cent_x(rect);
-	rect->ymin = rect->ymax = BLI_rctf_cent_y(rect);
-	rect->xmin -= x * 0.5f;
-	rect->ymin -= y * 0.5f;
+	rect->xmin = BLI_rctf_cent_x(rect) - (x * 0.5f);
+	rect->ymin = BLI_rctf_cent_y(rect) - (y * 0.5f);
 	rect->xmax = rect->xmin + x;
 	rect->ymax = rect->ymin + y;
 }
diff --git a/source/blender/blenlib/intern/string_utf8.c b/source/blender/blenlib/intern/string_utf8.c
index 96033615cf5..0ab11810b48 100644
--- a/source/blender/blenlib/intern/string_utf8.c
+++ b/source/blender/blenlib/intern/string_utf8.c
@@ -47,6 +47,19 @@
 
 // #define DEBUG_STRSIZE
 
+/* array copied from glib's gutf8.c, */
+/* Note: last two values (0xfe and 0xff) are forbidden in utf-8, so they are considered 1 byte length too. */
+static const size_t utf8_skip_data[256] = {
+	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
+	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
+	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
+	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
+	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
+	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
+	2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
+	3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4, 5, 5, 5, 5, 6, 6, 1, 1
+};
+
 /* from libswish3, originally called u8_isvalid(),
  * modified to return the index of the bad character (byte index not utf).
  * http://svn.swish-e.org/libswish3/trunk/src/libswish3/utf8.c r3044 - campbell */
@@ -56,73 +69,91 @@
  * length is in bytes, since without knowing whether the string is valid
  * it's hard to know how many characters there are! */
 
-static const char trailingBytesForUTF8[256] = {
-	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
-	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
-	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
-	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
-	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
-	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
-	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
-	2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5
-};
-
+/**
+ * Find first utf-8 invalid byte in given \a str, of \a length bytes.
+ *
+ * \return the offset of the first invalid byte.
+ */
 int BLI_utf8_invalid_byte(const char *str, int length)
 {
-	const unsigned char *p, *pend = (const unsigned char *)str + length;
+	const unsigned char *p, *perr, *pend = (const unsigned char *)str + length;
 	unsigned char c;
 	int ab;
 
-	for (p = (const unsigned char *)str; p < pend; p++) {
+	for (p = (const unsigned char *)str; p < pend; p++, length--) {
 		c = *p;
+		perr = p;  /* Erroneous char is always the first of an invalid utf8 sequence... */
+		if (ELEM(c, 0xfe, 0xff, 0x00))  /* Those three values are not allowed in utf8 string. */
+			goto utf8_error;
 		if (c < 128)
 			continue;
 		if ((c & 0xc0) != 0xc0)
 			goto utf8_error;
-		ab = trailingBytesForUTF8[c];
-		if (length < ab)
+
+		/* Note that since we always increase p (and decrease length) by one byte in main loop, we only add/subtract
+		 * extra utf8 bytes in code below
+		 * (ab number, aka number of bytes remaining in the utf8 sequence after the initial one). */
+		ab = (int)utf8_skip_data[c] - 1;
+		if (length <= ab) {
 			goto utf8_error;
-		length -= ab;
+		}
 
-		p++;
 		/* Check top bits in the second byte */
+		p++;
+		length--;
 		if ((*p & 0xc0) != 0x80)
 			goto utf8_error;
 
 		/* Check for overlong sequences for each different length */
 		switch (ab) {
-			/* Check for xx00 000x */
-		case 1:
-			if ((c & 0x3e) == 0) goto utf8_error;
-			continue;   /* We know there aren't any more bytes to check */
-
-			/* Check for 1110 0000, xx0x xxxx */
-		case 2:
-			if (c == 0xe0 && (*p & 0x20) == 0) goto utf8_error;
-			break;
-
-			/* Check for 1111 0000, xx00 xxxx */
-		case 3:
-			if (c == 0xf0 && (*p & 0x30) == 0) goto utf8_error;
-			break;
-
-			/* Check for 1111 1000, xx00 0xxx */
-		case 4:
-			if (c == 0xf8 && (*p & 0x38) == 0) goto utf8_error;
-			break;
-
-			/* Check for leading 0xfe or 0xff,
-			 * and then for 1111 1100, xx00 00xx */
-		case 5:
-			if (c == 0xfe || c == 0xff ||
-			    (c == 0xfc && (*p & 0x3c) == 0)) goto utf8_error;
-			break;
+			case 1:
+				/* Check for xx00 000x */
+				if ((c & 0x3e) == 0) goto utf8_error;
+				continue;   /* We know there aren't any more bytes to check */
+
+			case 2:
+				/* Check for 1110 0000, xx0x xxxx */
+				if (c == 0xe0 && (*p & 0x20) == 0) goto utf8_error;
+				/* Some special cases, see section 5 of utf-8 decoder stress-test by Markus Kuhn
+				 * (https://www.cl.cam.ac.uk/~mgk25/ucs/examples/UTF-8-test.txt). */
+				/* From section 5.1 (and 5.2) */
+				if (c == 0xed) {
+					if (*p == 0xa0 && *(p + 1) == 0x80) goto utf8_error;
+					if (*p == 0xad && *(p + 1) == 0xbf) goto utf8_error;
+					if (*p == 0xae && *(p + 1) == 0x80) goto utf8_error;
+					if (*p == 0xaf && *(p + 1) == 0xbf) goto utf8_error;
+					if (*p == 0xb0 && *(p + 1) == 0x80) goto utf8_error;
+					if (*p == 0xbe && *(p + 1) == 0x80) goto utf8_error;
+					if (*p == 0xbf && *(p + 1) == 0xbf) goto utf8_error;
+				}
+				/* From section 5.3 */
+				if (c == 0xef) {
+					if (*p == 0xbf && *(p + 1) == 0xbe) goto utf8_error;
+					if (*p == 0xbf && *(p + 1) == 0xbf) goto utf8_error;
+				}
+				break;
+
+			case 3:
+				/* Check for 1111 0000, xx00 xxxx */
+				if (c == 0xf0 && (*p & 0x30) == 0) goto utf8_error;
+				break;
+
+			case 4:
+				/* Check for 1111 1000, xx00 0xxx */
+				if (c == 0xf8 && (*p & 0x38) == 0) goto utf8_error;
+				break;
+
+			case 5:
+				/* Check for 1111 1100, xx00 00xx */
+				if (c == 0xfc && (*p & 0x3c) == 0) goto utf8_error;
+				break;
 		}
 
 		/* Check for valid bytes after the 2nd, if any; all must start 10 */
 		while (--ab > 0) {
-			if ((*(p + 1) & 0xc0) != 0x80) goto utf8_error;
-			p++; /* do this after so we get usable offset - campbell */
+			p++;
+			length--;
+			if ((*p & 0xc0) != 0x80) goto utf8_error;
 		}
 	}
 
@@ -130,7 +161,7 @@ int BLI_utf8_invalid_byte(const char *str, int length)
 
 utf8_error:
 
-	return (int)((const char *)p - (const char *)str) - 1;
+	return (int)((const char *)perr - (const char *)str);
 }
 
 int BLI_utf8_invalid_strip(char *str, int length)
@@ -141,7 +172,7 @@ int BLI_utf8_invalid_strip(char *str, int length)
 
 	while ((bad_char = BLI_utf8_invalid_byte(str, length)) != -1) {
 		str += bad_char;
-		length -= bad_char;
+		length -= (bad_char + 1);
 
 		if (length == 0) {
 			/* last character bad, strip it */
@@ -151,7 +182,7 @@ int BLI_utf8_invalid_strip(char *str, int length)
 		}
 		else {
 			/* strip, keep looking */
-			memmove(str, str + 1, (size_t)length);
+			memmove(str, str + 1, (size_t)length + 1);  /* +1 for NULL char! */
 			tot++;
 		}
 	}
@@ -162,20 +193,6 @@ int BLI_utf8_invalid_strip(char *str, int length)
 
 /* compatible with BLI_strncpy, but esnure no partial utf8 chars */
 
-/* array copied from glib's gutf8.c,
- * note: this looks to be at odd's with 'trailingBytesForUTF8',
- * need to find out what gives here! - campbell */
-static const size_t utf8_skip_data[256] = {
-	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
-	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
-	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
-	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
-	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
-	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
-	2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
-	3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4, 5, 5, 5, 5, 6, 6, 1, 1
-};
-
 #define BLI_STR_UTF8_CPY(dst, src, maxncpy)                                   \
 	{                                                                         \
 		size_t utf8_size;                                                     \
diff --git a/source/blender/blenloader/intern/readfile.c b/source/blender/blenloader/intern/readfile.c
index a154d283f07..a63b9ed7d19 100644
--- a/source/blender/blenloader/intern/readfile.c
+++ b/source/blender/blenloader/intern/readfile.c
@@ -531,6 +531,8 @@ void blo_split_main(ListBase *mainlist, Main *main)
 	for (Library *lib = main->library.first; lib; lib = lib->id.next, i++) {
 		Main *libmain = BKE_main_new();
 		libmain->curlib = lib;
+		libmain->versionfile = lib->versionfile;
+		libmain->subversionfile = lib->subversionfile;
 		BLI_addtail(mainlist, libmain);
 		lib->temp_index = i;
 		lib_main_array[i] = libmain;
@@ -562,6 +564,10 @@ static void read_file_version(FileData *fd, Main *main)
 				break;
 		}
 	}
+	if (main->curlib) {
+		main->curlib->versionfile = main->versionfile;
+		main->curlib->subversionfile = main->subversionfile;
+	}
 }
 
 #ifdef USE_GHASH_BHEAD
@@ -8373,14 +8379,12 @@ static void do_versions(FileData *fd, Library *lib, Main *main)
 	/* don't forget to set version number in BKE_blender_version.h! */
 }
 
-#if 0 // XXX: disabled for now... we still don't have this in the right place in the loading code for it to work
-static void do_versions_after_linking(FileData *fd, Library *lib, Main *main)
+static void do_versions_after_linking(Main *main)
 {
-	/* old Animation System (using IPO's) needs to be converted to the new Animato system */
-	if (main->versionfile < 250)
-		do_versions_ipos_to_animato(main);
+	UNUSED_VARS(main);
+//	printf("%s for %s (%s), %d.%d\n", __func__, main->curlib ? main->curlib->name : main->name,
+//	       main->curlib ? "LIB" : "MAIN", main->versionfile, main->subversionfile);
 }
-#endif
 
 static void lib_link_all(FileData *fd, Main *main)
 {
@@ -8582,7 +8586,17 @@ BlendFileData *blo_read_file_internal(FileData *fd, const char *filepath)
 	
 	lib_link_all(fd, bfd->main);
 
-	//do_versions_after_linking(fd, NULL, bfd->main); // XXX: not here (or even in this function at all)! this causes crashes on many files - Aligorith (July 04, 2010)
+	/* Skip in undo case. */
+	if (fd->memfile == NULL) {
+		/* Yep, second splitting... but this is a very cheap operation, so no big deal. */
+		blo_split_main(&mainlist, bfd->main);
+		for (Main *mainvar = mainlist.first; mainvar; mainvar = mainvar->next) {
+			BLI_assert(mainvar->versionfile != 0);
+			do_versions_after_linking(mainvar);
+		}
+		blo_join_main(&mainlist);
+	}
+
 	BKE_main_id_tag_all(bfd->main, LIB_TAG_NEW, false);
 
 	lib_verify_nodetree(bfd->main, true);
@@ -9794,9 +9808,15 @@ static void give_base_to_objects(Main *mainvar, Scene *scene, View3D *v3d, Libra
 				if (active_lay) {
 					ob->lay = active_lay;
 				}
+				if (flag & FILE_AUTOSELECT) {
+					/* Note that link_object_postprocess() already checks for FILE_AUTOSELECT flag,
+					 * but it will miss objects from non-instanciated groups... */
+					ob->flag |= SELECT;
+					/* do NOT make base active here! screws up GUI stuff, if you want it do it on src/ level */
+				}
 
-				base->lay = ob->lay;
 				base->object = ob;
+				base->lay = ob->lay;
 				base->flag = ob->flag;
 
 				CLAMP_MIN(ob->id.us, 0);
@@ -10116,6 +10136,32 @@ Main *BLO_library_link_begin(Main *mainvar, BlendHandle **bh, const char *filepa
 	return library_link_begin(mainvar, &fd, filepath);
 }
 
+static void split_main_newid(Main *mainptr, Main *main_newid)
+{
+	/* We only copy the necessary subset of data in this temp main. */
+	main_newid->versionfile = mainptr->versionfile;
+	main_newid->subversionfile = mainptr->subversionfile;
+	BLI_strncpy(main_newid->name, mainptr->name, sizeof(main_newid->name));
+	main_newid->curlib = mainptr->curlib;
+
+	ListBase *lbarray[MAX_LIBARRAY];
+	ListBase *lbarray_newid[MAX_LIBARRAY];
+	int i = set_listbasepointers(mainptr, lbarray);
+	set_listbasepointers(main_newid, lbarray_newid);
+	while (i--) {
+		BLI_listbase_clear(lbarray_newid[i]);
+
+		for (ID *id = lbarray[i]->first, *idnext; id; id = idnext) {
+			idnext = id->next;
+
+			if (id->tag & LIB_TAG_NEW) {
+				BLI_remlink(lbarray[i], id);
+				BLI_addtail(lbarray_newid[i], id);
+			}
+		}
+	}
+}
+
 /* scene and v3d may be NULL. */
 static void library_link_end(Main *mainl, FileData **fd, const short flag, Scene *scene, View3D *v3d)
 {
@@ -10144,11 +10190,26 @@ static void library_link_end(Main *mainl, FileData **fd, const short flag, Scene
 
 	blo_join_main((*fd)->mainlist);
 	mainvar = (*fd)->mainlist->first;
-	MEM_freeN((*fd)->mainlist);
 	mainl = NULL; /* blo_join_main free's mainl, cant use anymore */
 
 	lib_link_all(*fd, mainvar);
 
+	/* Yep, second splitting... but this is a very cheap operation, so no big deal. */
+	blo_split_main((*fd)->mainlist, mainvar);
+	Main main_newid = {0};
+	for (mainvar = ((Main *)(*fd)->mainlist->first)->next; mainvar; mainvar = mainvar->next) {
+		BLI_assert(mainvar->versionfile != 0);
+		/* We need to split out IDs already existing, or they will go again through do_versions - bad, very bad! */
+		split_main_newid(mainvar, &main_newid);
+
+		do_versions_after_linking(&main_newid);
+
+		add_main_to_main(mainvar, &main_newid);
+	}
+	blo_join_main((*fd)->mainlist);
+	mainvar = (*fd)->mainlist->first;
+	MEM_freeN((*fd)->mainlist);
+
 	BKE_main_id_tag_all(mainvar, LIB_TAG_NEW, false);
 
 	lib_verify_nodetree(mainvar, false);
@@ -10221,32 +10282,6 @@ static int mainvar_id_tag_any_check(Main *mainvar, const short tag)
 	return false;
 }
 
-static void split_main_newid(Main *mainptr, Main *main_newid)
-{
-	/* We only copy the necessary subset of data in this temp main. */
-	main_newid->versionfile = mainptr->versionfile;
-	main_newid->subversionfile = mainptr->subversionfile;
-	BLI_strncpy(main_newid->name, mainptr->name, sizeof(main_newid->name));
-	main_newid->curlib = mainptr->curlib;
-
-	ListBase *lbarray[MAX_LIBARRAY];
-	ListBase *lbarray_newid[MAX_LIBARRAY];
-	int i = set_listbasepointers(mainptr, lbarray);
-	set_listbasepointers(main_newid, lbarray_newid);
-	while (i--) {
-		BLI_listbase_clear(lbarray_newid[i]);
-
-		for (ID *id = lbarray[i]->first, *idnext; id; id = idnext) {
-			idnext = id->next;
-
-			if (id->tag & LIB_TAG_NEW) {
-				BLI_remlink(lbarray[i], id);
-				BLI_addtail(lbarray_newid[i], id);
-			}
-		}
-	}
-}
-
 static void read_libraries(FileData *basefd, ListBase *mainlist)
 {
 	Main *mainl = mainlist->first;
diff --git a/source/blender/bmesh/intern/bmesh_interp.c b/source/blender/bmesh/intern/bmesh_interp.c
index f51013c3f1c..20ee31251e8 100644
--- a/source/blender/bmesh/intern/bmesh_interp.c
+++ b/source/blender/bmesh/intern/bmesh_interp.c
@@ -339,7 +339,7 @@ static bool mdisp_in_mdispquad(
 	compute_mdisp_quad(l_dst, l_dst_f_center, v1, v2, v3, v4, e1, e2);
 
 	/* expand quad a bit */
-	cent_quad_v3(c, v1, v2, v3, v4);
+	mid_v3_v3v3v3v3(c, v1, v2, v3, v4);
 	
 	sub_v3_v3(v1, c); sub_v3_v3(v2, c);
 	sub_v3_v3(v3, c); sub_v3_v3(v4, c);
diff --git a/source/blender/bmesh/tools/bmesh_bevel.c b/source/blender/bmesh/tools/bmesh_bevel.c
index 8340be81aa8..05169a2a976 100644
--- a/source/blender/bmesh/tools/bmesh_bevel.c
+++ b/source/blender/bmesh/tools/bmesh_bevel.c
@@ -57,6 +57,7 @@
 #define BEVEL_EPSILON_ANG DEG2RADF(2.0f)
 #define BEVEL_SMALL_ANG DEG2RADF(10.0f)
 #define BEVEL_MAX_ADJUST_PCT 10.0f
+#define BEVEL_MAX_AUTO_ADJUST_PCT 300.0f
 
 /* happens far too often, uncomment for development */
 // #define BEVEL_ASSERT_PROJECT
@@ -323,15 +324,33 @@ static bool edge_half_offset_changed(EdgeHalf *e)
 	       e->offset_r != e->offset_r_spec;
 }
 
-static bool any_edge_half_offset_changed(BevVert *bv)
+static float adjusted_rel_change(float val, float spec)
+{
+	float relchg;
+
+	relchg = 0.0f;
+	if (val != spec) {
+		if (spec == 0)
+			relchg = 1000.0f;  /* arbitrary large value */
+		else
+			relchg = fabsf((val - spec) / spec);
+	}
+	return relchg;
+}
+
+static float max_edge_half_offset_rel_change(BevVert *bv)
 {
 	int i;
+	float max_rel_change;
+	EdgeHalf *e;
 
+	max_rel_change = 0.0f;
 	for (i = 0; i < bv->edgecount; i++) {
-		if (edge_half_offset_changed(&bv->edges[i]))
-			return true;
+		e = &bv->edges[i];
+		max_rel_change = max_ff(max_rel_change, adjusted_rel_change(e->offset_l, e->offset_l_spec));
+		max_rel_change = max_ff(max_rel_change, adjusted_rel_change(e->offset_r, e->offset_r_spec));
 	}
-	return false;
+	return max_rel_change;
 }
 
 /* Return the next EdgeHalf after from_e that is beveled.
@@ -1951,6 +1970,7 @@ static void adjust_offsets(BevelParams *bp)
 	GHashIterator giter;
 	EdgeHalf *e, *efirst, *eother;
 	GSQueue *q;
+	float max_rel_adj;
 
 	BLI_assert(!bp->vertex_only);
 	GHASH_ITER(giter, bp->vert_hash) {
@@ -1966,7 +1986,7 @@ static void adjust_offsets(BevelParams *bp)
 		searchi = -1;
 		GHASH_ITER(giter, bp->vert_hash) {
 			bv = BLI_ghashIterator_getValue(&giter);
-			if (!bv->visited && any_edge_half_offset_changed(bv)) {
+			if (!bv->visited && max_edge_half_offset_rel_change(bv) > 0.0f) {
 				i = BM_elem_index_get(bv->v);
 				if (!searchbv || i < searchi) {
 					searchbv = bv;
@@ -1996,6 +2016,24 @@ static void adjust_offsets(BevelParams *bp)
 		}
 	}
 	BLI_gsqueue_free(q);
+
+	/* Should we auto-limit the error accumulation? Typically, spirals can lead to 100x relative adjustments,
+	 * and somewhat hacky mechanism of using bp->limit_offset to indicate "clamp the adjustments" is not
+	 * obvious to users, who almost certainaly want clamping in this situation.
+	 * The reason not to clamp always is that some models work better without it (e.g., Bent_test in regression
+	 * suite, where relative adjust maximum is about .6). */
+	if (!bp->limit_offset) {
+		max_rel_adj = 0.0f;
+		GHASH_ITER(giter, bp->vert_hash) {
+			bv = BLI_ghashIterator_getValue(&giter);
+			max_rel_adj = max_ff(max_rel_adj, max_edge_half_offset_rel_change(bv));
+		}
+		if (max_rel_adj > BEVEL_MAX_AUTO_ADJUST_PCT / 100.0f) {
+			bp->limit_offset = true;
+			adjust_offsets(bp);
+			bp->limit_offset = false;
+		}
+	}
 }
 
 /* Do the edges at bv form a "pipe"?
diff --git a/source/blender/editors/animation/anim_deps.c b/source/blender/editors/animation/anim_deps.c
index 437dd2b2de2..cc77a321a89 100644
--- a/source/blender/editors/animation/anim_deps.c
+++ b/source/blender/editors/animation/anim_deps.c
@@ -309,6 +309,28 @@ static void animchan_sync_fcurve(bAnimContext *ac, bAnimListElem *ale, FCurve **
 	}
 }
 
+/* perform syncing updates for GPencil Layers */
+static void animchan_sync_gplayer(bAnimContext *UNUSED(ac), bAnimListElem *ale)
+{
+	bGPDlayer *gpl = (bGPDlayer *)ale->data;
+	
+	/* Make sure the selection flags agree with the "active" flag.
+	 * The selection flags are used in the Dopesheet only, whereas
+	 * the active flag is used everywhere else. Hence, we try to
+	 * sync these here so that it all seems to be have as the user
+	 * expects - T50184
+	 *
+	 * Assume that we only really do this when the active status changes.
+	 * (NOTE: This may prove annoying if it means selection is always lost)
+	 */
+	if (gpl->flag & GP_LAYER_ACTIVE) {
+		gpl->flag |= GP_LAYER_SELECT;
+	}
+	else {
+		gpl->flag &= ~GP_LAYER_SELECT;
+	}
+}
+
 /* ---------------- */
  
 /* Main call to be exported to animation editors */
@@ -343,6 +365,10 @@ void ANIM_sync_animchannels_to_data(const bContext *C)
 			case ANIMTYPE_FCURVE:
 				animchan_sync_fcurve(&ac, ale, &active_fcurve);
 				break;
+				
+			case ANIMTYPE_GPLAYER:
+				animchan_sync_gplayer(&ac, ale);
+				break;
 		}
 	}
 	
diff --git a/source/blender/editors/gpencil/drawgpencil.c b/source/blender/editors/gpencil/drawgpencil.c
index 9da3c3ee088..2fd574d6523 100644
--- a/source/blender/editors/gpencil/drawgpencil.c
+++ b/source/blender/editors/gpencil/drawgpencil.c
@@ -1419,8 +1419,16 @@ static void gp_draw_data_layers(
 
 #undef GP_DRAWFLAG_APPLY
 		
-		/* draw 'onionskins' (frame left + right) */
-		if ((gpl->flag & GP_LAYER_ONIONSKIN) && !(dflag & GP_DRAWDATA_NO_ONIONS)) {
+		/* Draw 'onionskins' (frame left + right)
+		 *   - It is only possible to show these if the option is enabled
+		 *   - The "no onions" flag prevents ghosts from appearing during animation playback/scrubbing
+		 *     and in renders
+		 *   - The per-layer "always show" flag however overrides the playback/render restriction,
+		 *     allowing artists to selectively turn onionskins on/off during playback
+		 */
+		if ((gpl->flag & GP_LAYER_ONIONSKIN) && 
+		    ((dflag & GP_DRAWDATA_NO_ONIONS) == 0 || (gpl->flag & GP_LAYER_GHOST_ALWAYS))) 
+		{
 			/* Drawing method - only immediately surrounding (gstep = 0),
 			 * or within a frame range on either side (gstep > 0)
 			 */
diff --git a/source/blender/editors/include/ED_util.h b/source/blender/editors/include/ED_util.h
index a4afa958450..60c4b3593aa 100644
--- a/source/blender/editors/include/ED_util.h
+++ b/source/blender/editors/include/ED_util.h
@@ -60,6 +60,7 @@ void    ED_undo_redo(struct bContext *C);
 void    ED_OT_undo(struct wmOperatorType *ot);
 void    ED_OT_undo_push(struct wmOperatorType *ot);
 void    ED_OT_redo(struct wmOperatorType *ot);
+void    ED_OT_undo_redo(struct wmOperatorType *ot);
 void    ED_OT_undo_history(struct wmOperatorType *ot);
 
 int     ED_undo_operator_repeat(struct bContext *C, struct wmOperator *op);
diff --git a/source/blender/editors/interface/interface_layout.c b/source/blender/editors/interface/interface_layout.c
index 80d091c0fdb..b02a909d009 100644
--- a/source/blender/editors/interface/interface_layout.c
+++ b/source/blender/editors/interface/interface_layout.c
@@ -125,6 +125,11 @@ typedef struct uiItem {
 	int flag;
 } uiItem;
 
+enum {
+	UI_ITEM_FIXED     = 1 << 0,
+	UI_ITEM_MIN       = 1 << 1,
+};
+
 typedef struct uiButtonItem {
 	uiItem item;
 	uiBut *but;
@@ -232,6 +237,7 @@ static int ui_text_icon_width(uiLayout *layout, const char *name, int icon, bool
 	variable = (ui_layout_vary_direction(layout) == UI_ITEM_VARY_X);
 
 	if (variable) {
+		layout->item.flag |= UI_ITEM_MIN;
 		const uiFontStyle *fstyle = UI_FSTYLE_WIDGET;
 		/* it may seem odd that the icon only adds (UI_UNIT_X / 4)
 		 * but taking margins into account its fine */
@@ -1463,8 +1469,9 @@ void uiItemEnumR_string(uiLayout *layout, struct PointerRNA *ptr, const char *pr
 	for (a = 0; item[a].identifier; a++) {
 		if (item[a].value == ivalue) {
 			const char *item_name = name ? name : CTX_IFACE_(RNA_property_translation_context(prop), item[a].name);
+			const int flag = item_name[0] ? 0 : UI_ITEM_R_ICON_ONLY;
 
-			uiItemFullR(layout, ptr, prop, RNA_ENUM_VALUE, ivalue, 0, item_name, icon ? icon : item[a].icon);
+			uiItemFullR(layout, ptr, prop, RNA_ENUM_VALUE, ivalue, flag, item_name, icon ? icon : item[a].icon);
 			break;
 		}
 	}
@@ -2059,6 +2066,7 @@ static void ui_litem_estimate_row(uiLayout *litem)
 {
 	uiItem *item;
 	int itemw, itemh;
+	bool min_size_flag = true;
 
 	litem->w = 0;
 	litem->h = 0;
@@ -2066,12 +2074,26 @@ static void ui_litem_estimate_row(uiLayout *litem)
 	for (item = litem->items.first; item; item = item->next) {
 		ui_item_size(item, &itemw, &itemh);
 
+		if (item->type == ITEM_BUTTON) {
+			const uiBut *but = ((uiButtonItem *)item)->but;
+			const bool icon_only = (but->flag & UI_HAS_ICON) && (but->str == NULL || but->str[0] == '\0');
+
+			min_size_flag = min_size_flag && icon_only;
+		}
+		else {
+			min_size_flag = min_size_flag && (item->flag & UI_ITEM_MIN);
+		}
+
 		litem->w += itemw;
 		litem->h = MAX2(itemh, litem->h);
 
 		if (item->next)
 			litem->w += litem->space;
 	}
+
+	if (min_size_flag) {
+		litem->item.flag |= UI_ITEM_MIN;
+	}
 }
 
 static int ui_litem_min_width(int itemw)
@@ -2112,7 +2134,7 @@ static void ui_litem_layout_row(uiLayout *litem)
 		newtotw = totw;
 
 		for (item = litem->items.first; item; item = item->next) {
-			if (item->flag)
+			if (item->flag & UI_ITEM_FIXED)
 				continue;
 
 			ui_item_size(item, &itemw, &itemh);
@@ -2125,16 +2147,19 @@ static void ui_litem_layout_row(uiLayout *litem)
 
 			x += neww;
 
-			if ((neww < minw || itemw == minw) && w != 0) {
+			if ((neww < minw || itemw == minw || item->flag & UI_ITEM_MIN) && w != 0) {
 				/* fixed size */
-				item->flag = 1;
+				item->flag |= UI_ITEM_FIXED;
+				if (item->type != ITEM_BUTTON && item->flag & UI_ITEM_MIN) {
+					minw = itemw;
+				}
 				fixedw += minw;
 				flag = 1;
 				newtotw -= itemw;
 			}
 			else {
 				/* keep free size */
-				item->flag = 0;
+				item->flag &= ~UI_ITEM_FIXED;
 				freew += itemw;
 			}
 		}
@@ -2151,8 +2176,11 @@ static void ui_litem_layout_row(uiLayout *litem)
 		ui_item_size(item, &itemw, &itemh);
 		minw = ui_litem_min_width(itemw);
 
-		if (item->flag) {
+		if (item->flag & UI_ITEM_FIXED) {
 			/* fixed minimum size items */
+			if (item->type != ITEM_BUTTON && item->flag & UI_ITEM_MIN) {
+				minw = itemw;
+			}
 			itemw = ui_item_fit(minw, fixedx, fixedw, min_ii(w, fixedw), !item->next, litem->alignment);
 			fixedx += itemw;
 		}
@@ -2192,6 +2220,7 @@ static void ui_litem_estimate_column(uiLayout *litem)
 {
 	uiItem *item;
 	int itemw, itemh;
+	bool min_size_flag = true;
 
 	litem->w = 0;
 	litem->h = 0;
@@ -2199,12 +2228,26 @@ static void ui_litem_estimate_column(uiLayout *litem)
 	for (item = litem->items.first; item; item = item->next) {
 		ui_item_size(item, &itemw, &itemh);
 
+		if (item->type == ITEM_BUTTON) {
+			const uiBut *but = ((uiButtonItem *)item)->but;
+			const bool icon_only = (but->flag & UI_HAS_ICON) && (but->str == NULL || but->str[0] == '\0');
+			
+			min_size_flag = min_size_flag && icon_only;
+		}
+		else {
+			min_size_flag = min_size_flag && (item->flag & UI_ITEM_MIN);
+		}
+
 		litem->w = MAX2(litem->w, itemw);
 		litem->h += itemh;
 
 		if (item->next)
 			litem->h += litem->space;
 	}
+
+	if (min_size_flag) {
+		litem->item.flag |= UI_ITEM_MIN;
+	}
 }
 
 static void ui_litem_layout_column(uiLayout *litem)
diff --git a/source/blender/editors/interface/interface_utils.c b/source/blender/editors/interface/interface_utils.c
index 8dfbbdd02eb..df6f098ee81 100644
--- a/source/blender/editors/interface/interface_utils.c
+++ b/source/blender/editors/interface/interface_utils.c
@@ -119,12 +119,10 @@ uiBut *uiDefAutoButR(uiBlock *block, PointerRNA *ptr, PropertyRNA *prop, int ind
 			else
 				but = uiDefButR_prop(block, UI_BTYPE_TEXT, 0, name, x1, y1, x2, y2, ptr, prop, index, 0, 0, -1, -1, NULL);
 
-			PropertySubType subtype = RNA_property_subtype(prop);
-			if (!(ELEM(subtype, PROP_FILEPATH, PROP_DIRPATH, PROP_FILENAME) || (block->flag & UI_BLOCK_LIST_ITEM))) {
-				UI_but_flag_enable(but, UI_BUT_VALUE_CLEAR);
-			}
 			if (RNA_property_flag(prop) & PROP_TEXTEDIT_UPDATE) {
-				UI_but_flag_enable(but, UI_BUT_TEXTEDIT_UPDATE);
+				/* TEXTEDIT_UPDATE is usally used for search buttons. For these we also want
+				 * the 'x' icon to clear search string, so setting VALUE_CLEAR flag, too. */
+				UI_but_flag_enable(but, UI_BUT_TEXTEDIT_UPDATE | UI_BUT_VALUE_CLEAR);
 			}
 			break;
 		case PROP_POINTER:
diff --git a/source/blender/editors/object/object_add.c b/source/blender/editors/object/object_add.c
index f42dafd094c..02b2d8492b4 100644
--- a/source/blender/editors/object/object_add.c
+++ b/source/blender/editors/object/object_add.c
@@ -1111,7 +1111,9 @@ static void object_delete_check_glsl_update(Object *ob)
 /* note: now unlinks constraints as well */
 void ED_base_object_free_and_unlink(Main *bmain, Scene *scene, Base *base)
 {
-	if (BKE_library_ID_is_indirectly_used(bmain, base->object) && ID_REAL_USERS(base->object) <= 1) {
+	if (BKE_library_ID_is_indirectly_used(bmain, base->object) &&
+	    ID_REAL_USERS(base->object) <= 1 && ID_EXTRA_USERS(base->object) == 0)
+	{
 		/* We cannot delete indirectly used object... */
 		printf("WARNING, undeletable object '%s', should have been catched before reaching this function!",
 		       base->object->id.name + 2);
@@ -1145,7 +1147,7 @@ static int object_delete_exec(bContext *C, wmOperator *op)
 			BKE_reportf(op->reports, RPT_WARNING, "Cannot delete indirectly linked object '%s'", base->object->id.name + 2);
 			continue;
 		}
-		else if (is_indirectly_used && ID_REAL_USERS(base->object) <= 1) {
+		else if (is_indirectly_used && ID_REAL_USERS(base->object) <= 1 && ID_EXTRA_USERS(base->object) == 0) {
 			BKE_reportf(op->reports, RPT_WARNING,
 			        "Cannot delete object '%s' from scene '%s', indirectly used objects need at least one user",
 			        base->object->id.name + 2, scene->id.name + 2);
@@ -1179,7 +1181,7 @@ static int object_delete_exec(bContext *C, wmOperator *op)
 				if (scene_iter != scene && !ID_IS_LINKED_DATABLOCK(scene_iter)) {
 					base_other = BKE_scene_base_find(scene_iter, base->object);
 					if (base_other) {
-						if (is_indirectly_used && ID_REAL_USERS(base->object) <= 1) {
+						if (is_indirectly_used && ID_REAL_USERS(base->object) <= 1 && ID_EXTRA_USERS(base->object) == 0) {
 							BKE_reportf(op->reports, RPT_WARNING,
 							            "Cannot delete object '%s' from scene '%s', indirectly used objects need at least one user",
 							            base->object->id.name + 2, scene_iter->id.name + 2);
diff --git a/source/blender/editors/object/object_modifier.c b/source/blender/editors/object/object_modifier.c
index b44ddf925a8..06f495fb9f1 100644
--- a/source/blender/editors/object/object_modifier.c
+++ b/source/blender/editors/object/object_modifier.c
@@ -98,12 +98,12 @@ ModifierData *ED_object_modifier_add(ReportList *reports, Main *bmain, Scene *sc
 	ModifierData *md = NULL, *new_md = NULL;
 	const ModifierTypeInfo *mti = modifierType_getInfo(type);
 	
-	/* only geometry objects should be able to get modifiers [#25291] */
-	if (!ELEM(ob->type, OB_MESH, OB_CURVE, OB_SURF, OB_FONT, OB_LATTICE)) {
+	/* Check compatibility of modifier [T25291, T50373]. */
+	if (!BKE_object_support_modifier_type_check(ob, type)) {
 		BKE_reportf(reports, RPT_WARNING, "Modifiers cannot be added to object '%s'", ob->id.name + 2);
 		return NULL;
 	}
-	
+
 	if (mti->flags & eModifierTypeFlag_Single) {
 		if (modifiers_findByType(ob, type)) {
 			BKE_report(reports, RPT_WARNING, "Only one modifier of this type is allowed");
diff --git a/source/blender/editors/screen/screen_ops.c b/source/blender/editors/screen/screen_ops.c
index c69e01422e0..a7a0a240259 100644
--- a/source/blender/editors/screen/screen_ops.c
+++ b/source/blender/editors/screen/screen_ops.c
@@ -4329,6 +4329,7 @@ void ED_operatortypes_screen(void)
 	WM_operatortype_append(ED_OT_undo);
 	WM_operatortype_append(ED_OT_undo_push);
 	WM_operatortype_append(ED_OT_redo);
+	WM_operatortype_append(ED_OT_undo_redo);
 	WM_operatortype_append(ED_OT_undo_history);
 
 	WM_operatortype_append(ED_OT_flush_edits);
diff --git a/source/blender/editors/sculpt_paint/sculpt.c b/source/blender/editors/sculpt_paint/sculpt.c
index 47f0220726b..84e98181dfb 100644
--- a/source/blender/editors/sculpt_paint/sculpt.c
+++ b/source/blender/editors/sculpt_paint/sculpt.c
@@ -5693,11 +5693,11 @@ static int sculpt_set_detail_size_exec(bContext *C, wmOperator *UNUSED(op))
 	WM_operator_properties_create_ptr(&props_ptr, ot);
 
 	if (sd->flags & SCULPT_DYNTOPO_DETAIL_CONSTANT) {
-		set_brush_rc_props(&props_ptr, "sculpt", "constant_detail", NULL, 0);
-		RNA_string_set(&props_ptr, "data_path_primary", "tool_settings.sculpt.constant_detail");
+		set_brush_rc_props(&props_ptr, "sculpt", "constant_detail_resolution", NULL, 0);
+		RNA_string_set(&props_ptr, "data_path_primary", "tool_settings.sculpt.constant_detail_resolution");
 	}
 	else if (sd->flags & SCULPT_DYNTOPO_DETAIL_BRUSH) {
-		set_brush_rc_props(&props_ptr, "sculpt", "constant_detail", NULL, 0);
+		set_brush_rc_props(&props_ptr, "sculpt", "constant_detail_resolution", NULL, 0);
 		RNA_string_set(&props_ptr, "data_path_primary", "tool_settings.sculpt.detail_percent");
 	}
 	else {
diff --git a/source/blender/editors/sound/sound_ops.c b/source/blender/editors/sound/sound_ops.c
index 432918f0e37..c2c52f58181 100644
--- a/source/blender/editors/sound/sound_ops.c
+++ b/source/blender/editors/sound/sound_ops.c
@@ -383,6 +383,8 @@ static int sound_mixdown_exec(bContext *C, wmOperator *op)
 		result = AUD_mixdown(scene->sound_scene, SFRA * specs.rate / FPS, (EFRA - SFRA + 1) * specs.rate / FPS,
 		                     accuracy, filename, specs, container, codec, bitrate);
 
+	BKE_sound_reset_scene_specs(scene);
+
 	if (result) {
 		BKE_report(op->reports, RPT_ERROR, result);
 		return OPERATOR_CANCELLED;
diff --git a/source/blender/editors/space_action/space_action.c b/source/blender/editors/space_action/space_action.c
index 671d6bb083e..83655a2ba9e 100644
--- a/source/blender/editors/space_action/space_action.c
+++ b/source/blender/editors/space_action/space_action.c
@@ -337,7 +337,7 @@ static void action_channel_region_listener(bScreen *UNUSED(sc), ScrArea *UNUSED(
 			}
 			break;
 		case NC_GPENCIL:
-			if (wmn->action == NA_RENAME)
+			if (ELEM(wmn->action, NA_RENAME, NA_SELECTED))
 				ED_region_tag_redraw(ar);
 			break;
 		case NC_ID:
@@ -407,10 +407,15 @@ static void action_listener(bScreen *UNUSED(sc), ScrArea *sa, wmNotifier *wmn)
 	/* context changes */
 	switch (wmn->category) {
 		case NC_GPENCIL:
-			if (wmn->action == NA_EDITED) {
-				/* only handle this event in GPencil mode for performance considerations */
-				if (saction->mode == SACTCONT_GPENCIL)
+			/* only handle these events in GPencil mode for performance considerations */
+			if (saction->mode == SACTCONT_GPENCIL) {
+				if (wmn->action == NA_EDITED) {
 					ED_area_tag_redraw(sa);
+				}
+				else if (wmn->action == NA_SELECTED) {
+					saction->flag |= SACTION_TEMP_NEEDCHANSYNC;
+					ED_area_tag_refresh(sa);
+				}
 			}
 			break;
 		case NC_ANIMATION:
diff --git a/source/blender/editors/space_image/image_ops.c b/source/blender/editors/space_image/image_ops.c
index 116f621dd76..2de3238de6c 100644
--- a/source/blender/editors/space_image/image_ops.c
+++ b/source/blender/editors/space_image/image_ops.c
@@ -1475,7 +1475,10 @@ static int image_match_len_exec(bContext *C, wmOperator *UNUSED(op))
 	if (!ima || !iuser || !BKE_image_has_anim(ima))
 		return OPERATOR_CANCELLED;
 
-	iuser->frames = IMB_anim_get_duration(((ImageAnim *) ima->anims.first)->anim, IMB_TC_RECORD_RUN);
+	struct anim *anim = ((ImageAnim *)ima->anims.first)->anim;
+	if (!anim)
+		return OPERATOR_CANCELLED;
+	iuser->frames = IMB_anim_get_duration(anim, IMB_TC_RECORD_RUN);
 	BKE_image_user_frame_calc(iuser, scene->r.cfra, 0);
 
 	return OPERATOR_FINISHED;
diff --git a/source/blender/editors/space_outliner/outliner_tools.c b/source/blender/editors/space_outliner/outliner_tools.c
index 7739d241bd3..4eda7977622 100644
--- a/source/blender/editors/space_outliner/outliner_tools.c
+++ b/source/blender/editors/space_outliner/outliner_tools.c
@@ -411,7 +411,9 @@ static void object_delete_cb(
 			BKE_reportf(reports, RPT_WARNING, "Cannot delete indirectly linked object '%s'", base->object->id.name + 2);
 			return;
 		}
-		else if (BKE_library_ID_is_indirectly_used(bmain, base->object) && ID_REAL_USERS(base->object) <= 1) {
+		else if (BKE_library_ID_is_indirectly_used(bmain, base->object) &&
+		         ID_REAL_USERS(base->object) <= 1 && ID_EXTRA_USERS(base->object) == 0)
+		{
 			BKE_reportf(reports, RPT_WARNING,
 			            "Cannot delete object '%s' from scene '%s', indirectly used objects need at least one user",
 			            base->object->id.name + 2, scene->id.name + 2);
@@ -525,7 +527,7 @@ static void group_linkobs2scene_cb(
 		if (!base) {
 			/* link to scene */
 			base = BKE_scene_base_add(scene, gob->ob);
-			id_lib_extern((ID *)gob->ob); /* in case these are from a linked group */
+			id_us_plus(&gob->ob->id);
 		}
 		base->object->flag |= SELECT;
 		base->flag |= SELECT;
@@ -842,7 +844,9 @@ static Base *outline_delete_hierarchy(bContext *C, ReportList *reports, Scene *s
 		BKE_reportf(reports, RPT_WARNING, "Cannot delete indirectly linked object '%s'", base->object->id.name + 2);
 		return base_next;
 	}
-	else if (BKE_library_ID_is_indirectly_used(bmain, base->object) && ID_REAL_USERS(base->object) <= 1) {
+	else if (BKE_library_ID_is_indirectly_used(bmain, base->object) &&
+	         ID_REAL_USERS(base->object) <= 1 && ID_EXTRA_USERS(base->object) == 0)
+	{
 		BKE_reportf(reports, RPT_WARNING,
 		            "Cannot delete object '%s' from scene '%s', indirectly used objects need at least one user",
 		            base->object->id.name + 2, scene->id.name + 2);
diff --git a/source/blender/editors/space_text/text_ops.c b/source/blender/editors/space_text/text_ops.c
index 83012eac39e..df3620843ad 100644
--- a/source/blender/editors/space_text/text_ops.c
+++ b/source/blender/editors/space_text/text_ops.c
@@ -254,6 +254,7 @@ static int text_open_exec(bContext *C, wmOperator *op)
 	}
 	else if (st) {
 		st->text = text;
+		id_us_ensure_real(&text->id);
 		st->left = 0;
 		st->top = 0;
 		st->scroll_accum[0] = 0.0f;
diff --git a/source/blender/editors/space_view3d/view3d_buttons.c b/source/blender/editors/space_view3d/view3d_buttons.c
index b9c8c98b62f..351c7ccec15 100644
--- a/source/blender/editors/space_view3d/view3d_buttons.c
+++ b/source/blender/editors/space_view3d/view3d_buttons.c
@@ -476,7 +476,7 @@ static void v3d_editvertex_buts(uiLayout *layout, View3D *v3d, Object *ob, float
 				uiDefButF(block, UI_BTYPE_NUM, B_OBJECTPANELMEDIAN,
 				          totedgedata == 1 ? IFACE_("Crease:") : IFACE_("Mean Crease:"),
 				          0, yi -= buth + but_margin, 200, buth,
-				          &(tfp->ve_median[M_CREASE]), 0.0, 1.0, 1, 2, TIP_("Weight used by SubSurf modifier"));
+				          &(tfp->ve_median[M_CREASE]), 0.0, 1.0, 1, 2, TIP_("Weight used by the Subdivision Surface modifier"));
 			}
 		}
 		/* Curve... */
@@ -491,7 +491,7 @@ static void v3d_editvertex_buts(uiLayout *layout, View3D *v3d, Object *ob, float
 		else if (totcurvedata > 1) {
 			uiDefButF(block, UI_BTYPE_NUM, B_OBJECTPANELMEDIAN, IFACE_("Mean Weight:"),
 			          0, yi -= buth + but_margin, 200, buth,
-			          &(tfp->ve_median[C_WEIGHT]), 0.0, 1.0, 1, 3, TIP_("Weight used for SoftBody Goal"));
+			          &(tfp->ve_median[C_WEIGHT]), 0.0, 1.0, 1, 3, TIP_("Weight used for Soft Body Goal"));
 			uiDefButF(block, UI_BTYPE_NUM, B_OBJECTPANELMEDIAN, IFACE_("Mean Radius:"),
 			          0, yi -= buth + but_margin, 200, buth,
 			          &(tfp->ve_median[C_RADIUS]), 0.0, 100.0, 1, 3, TIP_("Radius of curve control points"));
@@ -509,7 +509,7 @@ static void v3d_editvertex_buts(uiLayout *layout, View3D *v3d, Object *ob, float
 		else if (totlattdata > 1) {
 			uiDefButF(block, UI_BTYPE_NUM, B_OBJECTPANELMEDIAN, IFACE_("Mean Weight:"),
 			          0, yi -= buth + but_margin, 200, buth,
-			          &(tfp->ve_median[L_WEIGHT]), 0.0, 1.0, 1, 3, TIP_("Weight used for SoftBody Goal"));
+			          &(tfp->ve_median[L_WEIGHT]), 0.0, 1.0, 1, 3, TIP_("Weight used for Soft Body Goal"));
 		}
 
 		UI_block_align_end(block);
diff --git a/source/blender/editors/space_view3d/view3d_edit.c b/source/blender/editors/space_view3d/view3d_edit.c
index 620bbf03f32..2b53eb71d99 100644
--- a/source/blender/editors/space_view3d/view3d_edit.c
+++ b/source/blender/editors/space_view3d/view3d_edit.c
@@ -4064,6 +4064,9 @@ static int vieworbit_exec(bContext *C, wmOperator *op)
 
 			mul_qt_qtqt(quat_new, rv3d->viewquat, quat_mul);
 
+			/* avoid precision loss over time */
+			normalize_qt(quat_new);
+
 			if (view_opposite != RV3D_VIEW_USER) {
 				rv3d->view = view_opposite;
 				/* avoid float in-precision, just get a new orientation */
@@ -4130,6 +4133,10 @@ static void view_roll_angle(ARegion *ar, float quat[4], const float orig_quat[4]
 	axis_angle_normalized_to_quat(quat_mul, dvec, angle);
 
 	mul_qt_qtqt(quat, orig_quat, quat_mul);
+
+	/* avoid precision loss over time */
+	normalize_qt(quat);
+
 	rv3d->view = RV3D_VIEW_USER;
 }
 
diff --git a/source/blender/editors/space_view3d/view3d_header.c b/source/blender/editors/space_view3d/view3d_header.c
index 0713377d210..bf1bdf68619 100644
--- a/source/blender/editors/space_view3d/view3d_header.c
+++ b/source/blender/editors/space_view3d/view3d_header.c
@@ -337,13 +337,13 @@ void uiTemplateHeader3D(uiLayout *layout, struct bContext *C)
 	/* Draw type */
 	uiItemR(layout, &v3dptr, "viewport_shade", UI_ITEM_R_ICON_ONLY, "", ICON_NONE);
 
-	if (obedit == NULL && is_paint) {
-		if (ob->mode & OB_MODE_ALL_PAINT) {
-			/* Only for Weight Paint. makes no sense in other paint modes. */
-			row = uiLayoutRow(layout, true);
-			uiItemR(row, &v3dptr, "pivot_point", UI_ITEM_R_ICON_ONLY, "", ICON_NONE);
-		}
+	row = uiLayoutRow(layout, true);
+	uiItemR(row, &v3dptr, "pivot_point", UI_ITEM_R_ICON_ONLY, "", ICON_NONE);
+	if (!ob || ELEM(ob->mode, OB_MODE_OBJECT, OB_MODE_POSE, OB_MODE_WEIGHT_PAINT)) {
+		uiItemR(row, &v3dptr, "use_pivot_point_align", UI_ITEM_R_ICON_ONLY, "", ICON_NONE);
+	}
 
+	if (obedit == NULL && is_paint) {
 		/* Manipulators aren't used in paint modes */
 		if (!ELEM(ob->mode, OB_MODE_SCULPT, OB_MODE_PARTICLE_EDIT)) {
 			/* masks aren't used for sculpt and particle painting */
@@ -361,17 +361,6 @@ void uiTemplateHeader3D(uiLayout *layout, struct bContext *C)
 		}
 	}
 	else {
-		row = uiLayoutRow(layout, true);
-		uiItemR(row, &v3dptr, "pivot_point", UI_ITEM_R_ICON_ONLY, "", ICON_NONE);
-
-		/* pose/object only however we want to allow in weight paint mode too
-		 * so don't be totally strict and just check not-editmode for now 
-		 * XXX We never get here when we are in Weight Paint mode
-		 */
-		if (obedit == NULL) {
-			uiItemR(row, &v3dptr, "use_pivot_point_align", UI_ITEM_R_ICON_ONLY, "", ICON_NONE);
-		}
-
 		/* Transform widget / manipulators */
 		row = uiLayoutRow(layout, true);
 		uiItemR(row, &v3dptr, "show_manipulator", UI_ITEM_R_ICON_ONLY, "", ICON_NONE);
diff --git a/source/blender/editors/util/undo.c b/source/blender/editors/util/undo.c
index 4a9311416b3..fab5b7e821f 100644
--- a/source/blender/editors/util/undo.c
+++ b/source/blender/editors/util/undo.c
@@ -327,6 +327,13 @@ static int ed_redo_exec(bContext *C, wmOperator *UNUSED(op))
 	return ed_undo_step(C, -1, NULL);
 }
 
+static int ed_undo_redo_exec(bContext *C, wmOperator *UNUSED(op))
+{
+	wmOperator *last_op = WM_operator_last_redo(C);
+	const int ret = ED_undo_operator_repeat(C, last_op);
+	return ret ? OPERATOR_FINISHED : OPERATOR_CANCELLED;
+}
+
 
 /* ********************** */
 
@@ -369,6 +376,17 @@ void ED_OT_redo(wmOperatorType *ot)
 	ot->poll = ED_operator_screenactive;
 }
 
+void ED_OT_undo_redo(wmOperatorType *ot)
+{
+	/* identifiers */
+	ot->name = "Undo and Redo";
+	ot->description = "Undo and redo previous action";
+	ot->idname = "ED_OT_undo_redo";
+	
+	/* api callbacks */
+	ot->exec = ed_undo_redo_exec;
+	ot->poll = ED_operator_screenactive;
+}
 
 /* ui callbacks should call this rather than calling WM_operator_repeat() themselves */
 int ED_undo_operator_repeat(bContext *C, struct wmOperator *op)
diff --git a/source/blender/editors/uvedit/uvedit_unwrap_ops.c b/source/blender/editors/uvedit/uvedit_unwrap_ops.c
index 8e4ba4c0afa..d8080002818 100644
--- a/source/blender/editors/uvedit/uvedit_unwrap_ops.c
+++ b/source/blender/editors/uvedit/uvedit_unwrap_ops.c
@@ -1222,7 +1222,7 @@ static int unwrap_exec(bContext *C, wmOperator *op)
 	 * pass operator for warning append */
 	modifier_unwrap_state(obedit, scene, &use_subsurf_final);
 	if (use_subsurf != use_subsurf_final)
-		BKE_report(op->reports, RPT_INFO, "Subsurf modifier needs to be first to work with unwrap");
+		BKE_report(op->reports, RPT_INFO, "Subdivision Surface modifier needs to be first to work with unwrap");
 
 	/* execute unwrap */
 	ED_unwrap_lscm(scene, obedit, true);
@@ -1259,7 +1259,7 @@ void UV_OT_unwrap(wmOperatorType *ot)
 	RNA_def_boolean(ot->srna, "correct_aspect", 1, "Correct Aspect",
 	                "Map UVs taking image aspect ratio into account");
 	RNA_def_boolean(ot->srna, "use_subsurf_data", 0, "Use Subsurf Modifier",
-	                "Map UVs taking vertex position after subsurf into account");
+	                "Map UVs taking vertex position after Subdivision Surface modifier has been applied");
 	RNA_def_float_factor(ot->srna, "margin", 0.001f, 0.0f, 1.0f, "Margin", "Space between islands", 0.0f, 1.0f);
 }
 
diff --git a/source/blender/freestyle/intern/blender_interface/FRS_freestyle.cpp b/source/blender/freestyle/intern/blender_interface/FRS_freestyle.cpp
index 2af4447e4dc..223bc607e21 100644
--- a/source/blender/freestyle/intern/blender_interface/FRS_freestyle.cpp
+++ b/source/blender/freestyle/intern/blender_interface/FRS_freestyle.cpp
@@ -433,8 +433,8 @@ static void prepare(Render *re, SceneRenderLayer *srl)
 		cout << "Crease angle : " << controller->getCreaseAngle() << endl;
 		cout << "Sphere radius : " << controller->getSphereRadius() << endl;
 		cout << "Face smoothness : " << (controller->getFaceSmoothness() ? "enabled" : "disabled") << endl;
-		cout << "Redges and valleys : " << (controller->getComputeRidgesAndValleysFlag() ? "enabled" : "disabled") <<
-		        endl;
+		cout << "Ridges and valleys : " <<
+		        (controller->getComputeRidgesAndValleysFlag() ? "enabled" : "disabled") << endl;
 		cout << "Suggestive contours : " <<
 		        (controller->getComputeSuggestiveContoursFlag() ? "enabled" : "disabled") << endl;
 		cout << "Suggestive contour Kr derivative epsilon : " <<
diff --git a/source/blender/freestyle/intern/geometry/GeomUtils.cpp b/source/blender/freestyle/intern/geometry/GeomUtils.cpp
index 3eb92c559fe..cd7c1b83a4e 100644
--- a/source/blender/freestyle/intern/geometry/GeomUtils.cpp
+++ b/source/blender/freestyle/intern/geometry/GeomUtils.cpp
@@ -470,6 +470,8 @@ bool intersectRayTriangle(const Vec3r& orig, const Vec3r& dir, const Vec3r& v0,
 }
 
 // Intersection between plane and ray, adapted from Graphics Gems, Didier Badouel
+// The plane is represented by a set of points P implicitly defined as dot(norm, P) + d = 0.
+// The ray is represented as r(t) = orig + dir * t.
 intersection_test intersectRayPlane(const Vec3r& orig, const Vec3r& dir, const Vec3r& norm, const real d,
                                     real& t, const real epsilon)
 {
diff --git a/source/blender/freestyle/intern/view_map/ViewMapBuilder.cpp b/source/blender/freestyle/intern/view_map/ViewMapBuilder.cpp
index 380bb0dd3ca..794c782bb73 100644
--- a/source/blender/freestyle/intern/view_map/ViewMapBuilder.cpp
+++ b/source/blender/freestyle/intern/view_map/ViewMapBuilder.cpp
@@ -57,7 +57,7 @@ using namespace std;
 
 template <typename G, typename I>
 static void findOccludee(FEdge *fe, G& /*grid*/, I& occluders, real epsilon, WFace **oaWFace,
-                         Vec3r& u, Vec3r& A, Vec3r& origin, Vec3r& edge, vector<WVertex*>& faceVertices)
+                         Vec3r& u, Vec3r& A, Vec3r& origin, Vec3r& edgeDir, vector<WVertex*>& faceVertices)
 {
 	WFace *face = NULL;
 	if (fe->isSmooth()) {
@@ -125,7 +125,7 @@ static void findOccludee(FEdge *fe, G& /*grid*/, I& occluders, real epsilon, WFa
 				// check whether the edge and the polygon plane are coincident:
 				//-------------------------------------------------------------
 				//first let us compute the plane equation.
-				if (GeomUtils::COINCIDENT == GeomUtils::intersectRayPlane(origin, edge, p->getNormal(), d, t, epsilon))
+				if (GeomUtils::COINCIDENT == GeomUtils::intersectRayPlane(origin, edgeDir, p->getNormal(), d, t, epsilon))
 				{
 #if LOGGING
 					if (_global.debug & G_DEBUG_FREESTYLE) {
@@ -172,10 +172,11 @@ template <typename G, typename I>
 static void findOccludee(FEdge *fe, G& grid, real epsilon, ViewEdge * /*ve*/, WFace **oaFace)
 {
 	Vec3r A;
-	Vec3r edge;
+	Vec3r edgeDir;
 	Vec3r origin;
 	A = Vec3r(((fe)->vertexA()->point3D() + (fe)->vertexB()->point3D()) / 2.0);
-	edge = Vec3r((fe)->vertexB()->point3D() - (fe)->vertexA()->point3D());
+	edgeDir = Vec3r((fe)->vertexB()->point3D() - (fe)->vertexA()->point3D());
+	edgeDir.normalize();
 	origin = Vec3r((fe)->vertexA()->point3D());
 	Vec3r u;
 	if (grid.orthographicProjection()) {
@@ -199,7 +200,7 @@ static void findOccludee(FEdge *fe, G& grid, real epsilon, ViewEdge * /*ve*/, WF
 	}
 
 	I occluders(grid, A, epsilon);
-	findOccludee<G, I>(fe, grid, occluders, epsilon, oaFace, u, A, origin, edge, faceVertices);
+	findOccludee<G, I>(fe, grid, occluders, epsilon, oaFace, u, A, origin, edgeDir, faceVertices);
 }
 
 // computeVisibility takes a pointer to foundOccluders, instead of using a reference,
@@ -211,11 +212,12 @@ static int computeVisibility(ViewMap *viewMap, FEdge *fe, G& grid, real epsilon,
 	int qi = 0;
 
 	Vec3r center;
-	Vec3r edge;
+	Vec3r edgeDir;
 	Vec3r origin;
 
 	center = fe->center3d();
-	edge = Vec3r(fe->vertexB()->point3D() - fe->vertexA()->point3D());
+	edgeDir = Vec3r(fe->vertexB()->point3D() - fe->vertexA()->point3D());
+	edgeDir.normalize();
 	origin = Vec3r(fe->vertexA()->point3D());
 
 	Vec3r vp;
@@ -337,7 +339,7 @@ static int computeVisibility(ViewMap *viewMap, FEdge *fe, G& grid, real epsilon,
 			// check whether the edge and the polygon plane are coincident:
 			//-------------------------------------------------------------
 			//first let us compute the plane equation.
-			if (GeomUtils::COINCIDENT == GeomUtils::intersectRayPlane(origin, edge, p->getNormal(), d, t, epsilon)) {
+			if (GeomUtils::COINCIDENT == GeomUtils::intersectRayPlane(origin, edgeDir, p->getNormal(), d, t, epsilon)) {
 #if LOGGING
 				if (_global.debug & G_DEBUG_FREESTYLE) {
 					cout << "\t\tRejecting occluder for target coincidence." << endl;
@@ -391,7 +393,7 @@ static int computeVisibility(ViewMap *viewMap, FEdge *fe, G& grid, real epsilon,
 	}
 
 	// Find occludee
-	findOccludee<G, I>(fe, grid, occluders, epsilon, oaWFace, u, center, origin, edge, faceVertices);
+	findOccludee<G, I>(fe, grid, occluders, epsilon, oaWFace, u, center, origin, edgeDir, faceVertices);
 
 	return qi;
 }
@@ -1788,7 +1790,7 @@ void ViewMapBuilder::ComputeVeryFastRayCastingVisibility(ViewMap *ioViewMap, rea
 }
 
 void ViewMapBuilder::FindOccludee(FEdge *fe, Grid *iGrid, real epsilon, Polygon3r **oaPolygon, unsigned timestamp,
-                                  Vec3r& u, Vec3r& A, Vec3r& origin, Vec3r& edge, vector<WVertex*>& faceVertices)
+                                  Vec3r& u, Vec3r& A, Vec3r& origin, Vec3r& edgeDir, vector<WVertex*>& faceVertices)
 {
 	WFace *face = NULL;
 	if (fe->isSmooth()) {
@@ -1856,7 +1858,7 @@ void ViewMapBuilder::FindOccludee(FEdge *fe, Grid *iGrid, real epsilon, Polygon3
 					continue;
 			}
 			else {
-				if (GeomUtils::COINCIDENT == GeomUtils::intersectRayPlane(origin, edge, normal, d, t, epsilon))
+				if (GeomUtils::COINCIDENT == GeomUtils::intersectRayPlane(origin, edgeDir, normal, d, t, epsilon))
 					continue;
 			}
 			if ((*p)->rayIntersect(A, v, t, t_u, t_v)) {
@@ -1883,10 +1885,11 @@ void ViewMapBuilder::FindOccludee(FEdge *fe, Grid *iGrid, real epsilon, Polygon3
 	OccludersSet occluders;
 
 	Vec3r A;
-	Vec3r edge;
+	Vec3r edgeDir;
 	Vec3r origin;
 	A = Vec3r(((fe)->vertexA()->point3D() + (fe)->vertexB()->point3D()) / 2.0);
-	edge = Vec3r((fe)->vertexB()->point3D() - (fe)->vertexA()->point3D());
+	edgeDir = Vec3r((fe)->vertexB()->point3D() - (fe)->vertexA()->point3D());
+	edgeDir.normalize();
 	origin = Vec3r((fe)->vertexA()->point3D());
 	Vec3r u;
 	if (_orthographicProjection) {
@@ -1910,7 +1913,7 @@ void ViewMapBuilder::FindOccludee(FEdge *fe, Grid *iGrid, real epsilon, Polygon3
 	if (face)
 		face->RetrieveVertexList(faceVertices);
 
-	return FindOccludee(fe, iGrid, epsilon, oaPolygon, timestamp, u, A, origin, edge, faceVertices);
+	return FindOccludee(fe, iGrid, epsilon, oaPolygon, timestamp, u, A, origin, edgeDir, faceVertices);
 }
 
 int ViewMapBuilder::ComputeRayCastingVisibility(FEdge *fe, Grid *iGrid, real epsilon, set<ViewShape*>& oOccluders,
@@ -1920,11 +1923,12 @@ int ViewMapBuilder::ComputeRayCastingVisibility(FEdge *fe, Grid *iGrid, real eps
 	int qi = 0;
 
 	Vec3r center;
-	Vec3r edge;
+	Vec3r edgeDir;
 	Vec3r origin;
 
 	center = fe->center3d();
-	edge = Vec3r(fe->vertexB()->point3D() - fe->vertexA()->point3D());
+	edgeDir = Vec3r(fe->vertexB()->point3D() - fe->vertexA()->point3D());
+	edgeDir.normalize();
 	origin = Vec3r(fe->vertexA()->point3D());
 	// Is the edge outside the view frustum ?
 	Vec3r gridOrigin(iGrid->getOrigin());
@@ -2062,7 +2066,7 @@ int ViewMapBuilder::ComputeRayCastingVisibility(FEdge *fe, Grid *iGrid, real eps
 			//-------------------------------------------------------------
 			//first let us compute the plane equation.
 
-			if (GeomUtils::COINCIDENT == GeomUtils::intersectRayPlane(origin, edge, normal, d, t, epsilon)) {
+			if (GeomUtils::COINCIDENT == GeomUtils::intersectRayPlane(origin, edgeDir, normal, d, t, epsilon)) {
 #if LOGGING
 				if (_global.debug & G_DEBUG_FREESTYLE) {
 					cout << "\t\tRejecting occluder for target coincidence." << endl;
@@ -2099,7 +2103,7 @@ int ViewMapBuilder::ComputeRayCastingVisibility(FEdge *fe, Grid *iGrid, real eps
 	}
 
 	// Find occludee
-	FindOccludee(fe, iGrid, epsilon, oaPolygon, timestamp, u, center, origin, edge, faceVertices);
+	FindOccludee(fe, iGrid, epsilon, oaPolygon, timestamp, u, center, origin, edgeDir, faceVertices);
 
 	return qi;
 }
diff --git a/source/blender/freestyle/intern/view_map/ViewMapBuilder.h b/source/blender/freestyle/intern/view_map/ViewMapBuilder.h
index 36497bf8d22..440ae93c7df 100644
--- a/source/blender/freestyle/intern/view_map/ViewMapBuilder.h
+++ b/source/blender/freestyle/intern/view_map/ViewMapBuilder.h
@@ -250,7 +250,7 @@ protected:
 	// FIXME
 	void FindOccludee(FEdge *fe, Grid *iGrid, real epsilon, Polygon3r **oaPolygon, unsigned timestamp);
 	void FindOccludee(FEdge *fe, Grid *iGrid, real epsilon, Polygon3r **oaPolygon, unsigned timestamp,
-	                  Vec3r& u, Vec3r& A, Vec3r& origin, Vec3r& edge, vector<WVertex*>& faceVertices);
+	                  Vec3r& u, Vec3r& A, Vec3r& origin, Vec3r& edgeDir, vector<WVertex*>& faceVertices);
 
 #ifdef WITH_CXX_GUARDEDALLOC
 	MEM_CXX_CLASS_ALLOC_FUNCS("Freestyle:ViewMapBuilder")
diff --git a/source/blender/gpu/shaders/gpu_shader_fx_ssao_frag.glsl b/source/blender/gpu/shaders/gpu_shader_fx_ssao_frag.glsl
index 054a2f795ee..50c8e255162 100644
--- a/source/blender/gpu/shaders/gpu_shader_fx_ssao_frag.glsl
+++ b/source/blender/gpu/shaders/gpu_shader_fx_ssao_frag.glsl
@@ -27,8 +27,7 @@ vec3 calculate_view_space_normal(in vec3 viewposition)
 {
 	vec3 normal = cross(normalize(dFdx(viewposition)),
 	                    ssao_params.w * normalize(dFdy(viewposition)));
-	normalize(normal);
-	return normal;
+	return normalize(normal);
 }
 
 float calculate_ssao_factor(float depth)
diff --git a/source/blender/makesdna/DNA_ID.h b/source/blender/makesdna/DNA_ID.h
index 9a8f3da3396..2c6f3d2fc66 100644
--- a/source/blender/makesdna/DNA_ID.h
+++ b/source/blender/makesdna/DNA_ID.h
@@ -155,8 +155,9 @@ typedef struct Library {
 	
 	struct PackedFile *packedfile;
 
+	/* Temp data needed by read/write code. */
 	int temp_index;
-	int _pad;
+	short versionfile, subversionfile;  /* see BLENDER_VERSION, BLENDER_SUBVERSION, needed for do_versions */
 } Library;
 
 enum eIconSizes {
@@ -276,6 +277,7 @@ typedef enum ID_Type {
 
 #define ID_FAKE_USERS(id) ((((ID *)id)->flag & LIB_FAKEUSER) ? 1 : 0)
 #define ID_REAL_USERS(id) (((ID *)id)->us - ID_FAKE_USERS(id))
+#define ID_EXTRA_USERS(id) (((ID *)id)->tag & LIB_TAG_EXTRAUSER ? 1 : 0)
 
 #define ID_CHECK_UNDO(id) ((GS((id)->name) != ID_SCR) && (GS((id)->name) != ID_WM))
 
diff --git a/source/blender/makesdna/DNA_gpencil_types.h b/source/blender/makesdna/DNA_gpencil_types.h
index 23b73424da5..0364d855f69 100644
--- a/source/blender/makesdna/DNA_gpencil_types.h
+++ b/source/blender/makesdna/DNA_gpencil_types.h
@@ -244,6 +244,7 @@ typedef struct bGPDlayer {
 	float inverse[4][4];    /* inverse matrix (only used if parented) */
 	char parsubstr[64];     /* String describing subobject info, MAX_ID_NAME-2 */
 	short partype, pad;
+	
 	float tintcolor[4];     /* Color used to tint layer, alpha value is used as factor */
 	float opacity;          /* Opacity of the layer */
 } bGPDlayer;
@@ -275,7 +276,9 @@ typedef enum eGPDlayer_Flag {
 	/* Use high quality fill (instead of buggy legacy OpenGL Fill) */
 	GP_LAYER_HQ_FILL        = (1 << 11),
 	/* Unlock color */
-	GP_LAYER_UNLOCK_COLOR = (1 << 12)
+	GP_LAYER_UNLOCK_COLOR 	= (1 << 12),
+	/* always show onion skins (i.e. even during renders/animation playback) */
+	GP_LAYER_GHOST_ALWAYS	= (1 << 13),
 } eGPDlayer_Flag;
 
 /* Grease-Pencil Annotations - 'DataBlock' */
diff --git a/source/blender/makesrna/RNA_types.h b/source/blender/makesrna/RNA_types.h
index 1a191a68668..dee8df7d933 100644
--- a/source/blender/makesrna/RNA_types.h
+++ b/source/blender/makesrna/RNA_types.h
@@ -174,8 +174,10 @@ typedef enum PropertyFlag {
 	 * and collections */
 	PROP_ANIMATABLE              = (1 << 1),
 
-	/* This flag means when the property's widget is in 'textedit' mode, it will be updated after every typed char,
-	 * instead of waiting final validation. Used e.g. for text searchbox. */
+	/* This flag means when the property's widget is in 'textedit' mode, it will be updated
+	 * after every typed char, instead of waiting final validation. Used e.g. for text searchbox.
+	 * It will also cause UI_BUT_VALUE_CLEAR to be set for text buttons. We could add an own flag
+	 * for search/filter properties, but this works just fine for now. */
 	PROP_TEXTEDIT_UPDATE         = (1 << 31),
 
 	/* icon */
diff --git a/source/blender/makesrna/intern/rna_gpencil.c b/source/blender/makesrna/intern/rna_gpencil.c
index 69ee671901a..14da990278c 100644
--- a/source/blender/makesrna/intern/rna_gpencil.c
+++ b/source/blender/makesrna/intern/rna_gpencil.c
@@ -1242,6 +1242,13 @@ static void rna_def_gpencil_layer(BlenderRNA *brna)
 	RNA_def_property_ui_text(prop, "After Color", "Base color for ghosts after the active frame");
 	RNA_def_property_update(prop, NC_GPENCIL | ND_DATA, "rna_GPencil_update");
 	
+	prop = RNA_def_property(srna, "use_ghosts_always", PROP_BOOLEAN, PROP_NONE);
+	RNA_def_property_boolean_sdna(prop, NULL, "flag", GP_LAYER_GHOST_ALWAYS);
+	RNA_def_property_ui_text(prop, "Always Show Ghosts",
+	                         "Ghosts are shown in renders and animation playback. Useful for special effects (e.g. motion blur)");
+	RNA_def_property_update(prop, NC_GPENCIL | ND_DATA, "rna_GPencil_update");
+	
+	
 	/* Flags */
 	prop = RNA_def_property(srna, "hide", PROP_BOOLEAN, PROP_NONE);
 	RNA_def_property_boolean_sdna(prop, NULL, "flag", GP_LAYER_HIDE);
@@ -1276,13 +1283,13 @@ static void rna_def_gpencil_layer(BlenderRNA *brna)
 	RNA_def_property_boolean_sdna(prop, NULL, "flag", GP_LAYER_ACTIVE);
 	RNA_def_property_boolean_funcs(prop, NULL, "rna_GPencilLayer_active_set");
 	RNA_def_property_ui_text(prop, "Active", "Set active layer for editing");
-	RNA_def_property_update(prop, NC_GPENCIL | ND_DATA, NULL);
+	RNA_def_property_update(prop, NC_GPENCIL | ND_DATA | NA_SELECTED, NULL);
 #endif
 
 	prop = RNA_def_property(srna, "select", PROP_BOOLEAN, PROP_NONE);
 	RNA_def_property_boolean_sdna(prop, NULL, "flag", GP_LAYER_SELECT);
 	RNA_def_property_ui_text(prop, "Select", "Layer is selected for editing in the Dope Sheet");
-	RNA_def_property_update(prop, NC_GPENCIL | ND_DATA, "rna_GPencil_update");
+	RNA_def_property_update(prop, NC_GPENCIL | ND_DATA | NA_SELECTED, "rna_GPencil_update");
 	
 	/* XXX keep this option? */
 	prop = RNA_def_property(srna, "show_points", PROP_BOOLEAN, PROP_NONE);
@@ -1370,14 +1377,15 @@ static void rna_def_gpencil_layers_api(BlenderRNA *brna, PropertyRNA *cprop)
 	RNA_def_property_pointer_funcs(prop, "rna_GPencil_active_layer_get", "rna_GPencil_active_layer_set", NULL, NULL);
 	RNA_def_property_flag(prop, PROP_EDITABLE);
 	RNA_def_property_ui_text(prop, "Active Layer", "Active grease pencil layer");
+	RNA_def_property_update(prop, NC_GPENCIL | ND_DATA | NA_SELECTED, NULL);
 	
 	prop = RNA_def_property(srna, "active_index", PROP_INT, PROP_UNSIGNED);
-	
 	RNA_def_property_int_funcs(prop,
 	                           "rna_GPencil_active_layer_index_get", 
 	                           "rna_GPencil_active_layer_index_set", 
 	                           "rna_GPencil_active_layer_index_range");
 	RNA_def_property_ui_text(prop, "Active Layer Index", "Index of active grease pencil layer");
+	RNA_def_property_update(prop, NC_GPENCIL | ND_DATA | NA_SELECTED, NULL);
 }
 
 static void rna_def_gpencil_palettecolor(BlenderRNA *brna)
diff --git a/source/blender/makesrna/intern/rna_main_api.c b/source/blender/makesrna/intern/rna_main_api.c
index cecdb6bad51..c110dbff6c4 100644
--- a/source/blender/makesrna/intern/rna_main_api.c
+++ b/source/blender/makesrna/intern/rna_main_api.c
@@ -116,6 +116,13 @@
 #endif
 
 
+static void rna_idname_validate(const char *name, char *r_name)
+{
+	BLI_strncpy(r_name, name, MAX_ID_NAME - 2);
+	BLI_utf8_invalid_strip(r_name, strlen(r_name));
+}
+
+
 static void rna_Main_ID_remove(Main *bmain, ReportList *reports, PointerRNA *id_ptr, int do_unlink)
 {
 	ID *id = id_ptr->data;
@@ -137,14 +144,20 @@ static void rna_Main_ID_remove(Main *bmain, ReportList *reports, PointerRNA *id_
 
 static Camera *rna_Main_cameras_new(Main *bmain, const char *name)
 {
-	ID *id = BKE_camera_add(bmain, name);
+	char safe_name[MAX_ID_NAME - 2];
+	rna_idname_validate(name, safe_name);
+
+	ID *id = BKE_camera_add(bmain, safe_name);
 	id_us_min(id);
 	return (Camera *)id;
 }
 
 static Scene *rna_Main_scenes_new(Main *bmain, const char *name)
 {
-	return BKE_scene_add(bmain, name);
+	char safe_name[MAX_ID_NAME - 2];
+	rna_idname_validate(name, safe_name);
+
+	return BKE_scene_add(bmain, safe_name);
 }
 static void rna_Main_scenes_remove(Main *bmain, bContext *C, ReportList *reports, PointerRNA *scene_ptr, int do_unlink)
 {
@@ -180,6 +193,9 @@ static void rna_Main_scenes_remove(Main *bmain, bContext *C, ReportList *reports
 
 static Object *rna_Main_objects_new(Main *bmain, ReportList *reports, const char *name, ID *data)
 {
+	char safe_name[MAX_ID_NAME - 2];
+	rna_idname_validate(name, safe_name);
+
 	Object *ob;
 	int type = OB_EMPTY;
 	if (data) {
@@ -223,7 +239,7 @@ static Object *rna_Main_objects_new(Main *bmain, ReportList *reports, const char
 		id_us_plus(data);
 	}
 
-	ob = BKE_object_add_only_object(bmain, type, name);
+	ob = BKE_object_add_only_object(bmain, type, safe_name);
 	id_us_min(&ob->id);
 
 	ob->data = data;
@@ -234,7 +250,10 @@ static Object *rna_Main_objects_new(Main *bmain, ReportList *reports, const char
 
 static Material *rna_Main_materials_new(Main *bmain, const char *name)
 {
-	ID *id = (ID *)BKE_material_add(bmain, name);
+	char safe_name[MAX_ID_NAME - 2];
+	rna_idname_validate(name, safe_name);
+
+	ID *id = (ID *)BKE_material_add(bmain, safe_name);
 	id_us_min(id);
 	return (Material *)id;
 }
@@ -245,20 +264,27 @@ static EnumPropertyItem *rna_Main_nodetree_type_itemf(bContext *UNUSED(C), Point
 }
 static struct bNodeTree *rna_Main_nodetree_new(Main *bmain, const char *name, int type)
 {
+	char safe_name[MAX_ID_NAME - 2];
+	rna_idname_validate(name, safe_name);
+
 	bNodeTreeType *typeinfo = rna_node_tree_type_from_enum(type);
 	if (typeinfo) {
-		bNodeTree *ntree = ntreeAddTree(bmain, name, typeinfo->idname);
+		bNodeTree *ntree = ntreeAddTree(bmain, safe_name, typeinfo->idname);
 
 		id_us_min(&ntree->id);
 		return ntree;
 	}
-	else
+	else {
 		return NULL;
+	}
 }
 
 static Mesh *rna_Main_meshes_new(Main *bmain, const char *name)
 {
-	Mesh *me = BKE_mesh_add(bmain, name);
+	char safe_name[MAX_ID_NAME - 2];
+	rna_idname_validate(name, safe_name);
+
+	Mesh *me = BKE_mesh_add(bmain, safe_name);
 	id_us_min(&me->id);
 	return me;
 }
@@ -286,7 +312,10 @@ Mesh *rna_Main_meshes_new_from_object(
 
 static Lamp *rna_Main_lamps_new(Main *bmain, const char *name, int type)
 {
-	Lamp *lamp = BKE_lamp_add(bmain, name);
+	char safe_name[MAX_ID_NAME - 2];
+	rna_idname_validate(name, safe_name);
+
+	Lamp *lamp = BKE_lamp_add(bmain, safe_name);
 	lamp->type = type;
 	id_us_min(&lamp->id);
 	return lamp;
@@ -294,8 +323,11 @@ static Lamp *rna_Main_lamps_new(Main *bmain, const char *name, int type)
 
 static Image *rna_Main_images_new(Main *bmain, const char *name, int width, int height, int alpha, int float_buffer, int stereo3d)
 {
+	char safe_name[MAX_ID_NAME - 2];
+	rna_idname_validate(name, safe_name);
+
 	float color[4] = {0.0, 0.0, 0.0, 1.0};
-	Image *image = BKE_image_add_generated(bmain, width, height, name, alpha ? 32 : 24, float_buffer, 0, color, stereo3d);
+	Image *image = BKE_image_add_generated(bmain, width, height, safe_name, alpha ? 32 : 24, float_buffer, 0, color, stereo3d);
 	id_us_min(&image->id);
 	return image;
 }
@@ -322,21 +354,30 @@ static Image *rna_Main_images_load(Main *bmain, ReportList *reports, const char
 
 static Lattice *rna_Main_lattices_new(Main *bmain, const char *name)
 {
-	Lattice *lt = BKE_lattice_add(bmain, name);
+	char safe_name[MAX_ID_NAME - 2];
+	rna_idname_validate(name, safe_name);
+
+	Lattice *lt = BKE_lattice_add(bmain, safe_name);
 	id_us_min(&lt->id);
 	return lt;
 }
 
 static Curve *rna_Main_curves_new(Main *bmain, const char *name, int type)
 {
-	Curve *cu = BKE_curve_add(bmain, name, type);
+	char safe_name[MAX_ID_NAME - 2];
+	rna_idname_validate(name, safe_name);
+
+	Curve *cu = BKE_curve_add(bmain, safe_name, type);
 	id_us_min(&cu->id);
 	return cu;
 }
 
 static MetaBall *rna_Main_metaballs_new(Main *bmain, const char *name)
 {
-	MetaBall *mb = BKE_mball_add(bmain, name);
+	char safe_name[MAX_ID_NAME - 2];
+	rna_idname_validate(name, safe_name);
+
+	MetaBall *mb = BKE_mball_add(bmain, safe_name);
 	id_us_min(&mb->id);
 	return mb;
 }
@@ -364,7 +405,10 @@ static VFont *rna_Main_fonts_load(Main *bmain, ReportList *reports, const char *
 
 static Tex *rna_Main_textures_new(Main *bmain, const char *name, int type)
 {
-	Tex *tex = BKE_texture_add(bmain, name);
+	char safe_name[MAX_ID_NAME - 2];
+	rna_idname_validate(name, safe_name);
+
+	Tex *tex = BKE_texture_add(bmain, safe_name);
 	BKE_texture_type_set(tex, type);
 	id_us_min(&tex->id);
 	return tex;
@@ -372,26 +416,38 @@ static Tex *rna_Main_textures_new(Main *bmain, const char *name, int type)
 
 static Brush *rna_Main_brushes_new(Main *bmain, const char *name, int mode)
 {
-	Brush *brush = BKE_brush_add(bmain, name, mode);
+	char safe_name[MAX_ID_NAME - 2];
+	rna_idname_validate(name, safe_name);
+
+	Brush *brush = BKE_brush_add(bmain, safe_name, mode);
 	id_us_min(&brush->id);
 	return brush;
 }
 
 static World *rna_Main_worlds_new(Main *bmain, const char *name)
 {
-	World *world = add_world(bmain, name);
+	char safe_name[MAX_ID_NAME - 2];
+	rna_idname_validate(name, safe_name);
+
+	World *world = add_world(bmain, safe_name);
 	id_us_min(&world->id);
 	return world;
 }
 
 static Group *rna_Main_groups_new(Main *bmain, const char *name)
 {
-	return BKE_group_add(bmain, name);
+	char safe_name[MAX_ID_NAME - 2];
+	rna_idname_validate(name, safe_name);
+
+	return BKE_group_add(bmain, safe_name);
 }
 
 static Speaker *rna_Main_speakers_new(Main *bmain, const char *name)
 {
-	Speaker *speaker = BKE_speaker_add(bmain, name);
+	char safe_name[MAX_ID_NAME - 2];
+	rna_idname_validate(name, safe_name);
+
+	Speaker *speaker = BKE_speaker_add(bmain, safe_name);
 	id_us_min(&speaker->id);
 	return speaker;
 }
@@ -413,7 +469,10 @@ static bSound *rna_Main_sounds_load(Main *bmain, const char *name, int check_exi
 
 static Text *rna_Main_texts_new(Main *bmain, const char *name)
 {
-	return BKE_text_add(bmain, name);
+	char safe_name[MAX_ID_NAME - 2];
+	rna_idname_validate(name, safe_name);
+
+	return BKE_text_add(bmain, safe_name);
 }
 
 static Text *rna_Main_texts_load(Main *bmain, ReportList *reports, const char *filepath, int is_internal)
@@ -432,28 +491,40 @@ static Text *rna_Main_texts_load(Main *bmain, ReportList *reports, const char *f
 
 static bArmature *rna_Main_armatures_new(Main *bmain, const char *name)
 {
-	bArmature *arm = BKE_armature_add(bmain, name);
+	char safe_name[MAX_ID_NAME - 2];
+	rna_idname_validate(name, safe_name);
+
+	bArmature *arm = BKE_armature_add(bmain, safe_name);
 	id_us_min(&arm->id);
 	return arm;
 }
 
 static bAction *rna_Main_actions_new(Main *bmain, const char *name)
 {
-	bAction *act = add_empty_action(bmain, name);
+	char safe_name[MAX_ID_NAME - 2];
+	rna_idname_validate(name, safe_name);
+
+	bAction *act = add_empty_action(bmain, safe_name);
 	id_fake_user_clear(&act->id);
 	return act;
 }
 
 static ParticleSettings *rna_Main_particles_new(Main *bmain, const char *name)
 {
-	ParticleSettings *part = psys_new_settings(name, bmain);
+	char safe_name[MAX_ID_NAME - 2];
+	rna_idname_validate(name, safe_name);
+
+	ParticleSettings *part = psys_new_settings(safe_name, bmain);
 	id_us_min(&part->id);
 	return part;
 }
 
 static Palette *rna_Main_palettes_new(Main *bmain, const char *name)
 {
-	Palette *palette = BKE_palette_add(bmain, name);
+	char safe_name[MAX_ID_NAME - 2];
+	rna_idname_validate(name, safe_name);
+
+	Palette *palette = BKE_palette_add(bmain, safe_name);
 	id_us_min(&palette->id);
 	return (Palette *)palette;
 }
@@ -481,16 +552,18 @@ static MovieClip *rna_Main_movieclip_load(Main *bmain, ReportList *reports, cons
 
 static Mask *rna_Main_mask_new(Main *bmain, const char *name)
 {
-	Mask *mask;
-
-	mask = BKE_mask_new(bmain, name);
+	char safe_name[MAX_ID_NAME - 2];
+	rna_idname_validate(name, safe_name);
 
-	return mask;
+	return BKE_mask_new(bmain, safe_name);
 }
 
 static FreestyleLineStyle *rna_Main_linestyles_new(Main *bmain, const char *name)
 {
-	FreestyleLineStyle *linestyle = BKE_linestyle_new(bmain, name);
+	char safe_name[MAX_ID_NAME - 2];
+	rna_idname_validate(name, safe_name);
+
+	FreestyleLineStyle *linestyle = BKE_linestyle_new(bmain, safe_name);
 	id_us_min(&linestyle->id);
 	return linestyle;
 }
diff --git a/source/blender/makesrna/intern/rna_mesh.c b/source/blender/makesrna/intern/rna_mesh.c
index 3dc58442851..ad5f320625c 100644
--- a/source/blender/makesrna/intern/rna_mesh.c
+++ b/source/blender/makesrna/intern/rna_mesh.c
@@ -1962,7 +1962,7 @@ static void rna_def_medge(BlenderRNA *brna)
 
 	prop = RNA_def_property(srna, "crease", PROP_FLOAT, PROP_NONE);
 	RNA_def_property_float_funcs(prop, "rna_MEdge_crease_get", "rna_MEdge_crease_set", NULL);
-	RNA_def_property_ui_text(prop, "Crease", "Weight used by the Subsurf modifier for creasing");
+	RNA_def_property_ui_text(prop, "Crease", "Weight used by the Subdivision Surface modifier for creasing");
 	RNA_def_property_update(prop, 0, "rna_Mesh_update_data");
 
 	prop = RNA_def_property(srna, "bevel_weight", PROP_FLOAT, PROP_NONE);
@@ -1987,7 +1987,7 @@ static void rna_def_medge(BlenderRNA *brna)
 
 	prop = RNA_def_property(srna, "use_edge_sharp", PROP_BOOLEAN, PROP_NONE);
 	RNA_def_property_boolean_sdna(prop, NULL, "flag", ME_SHARP);
-	RNA_def_property_ui_text(prop, "Sharp", "Sharp edge for the EdgeSplit modifier");
+	RNA_def_property_ui_text(prop, "Sharp", "Sharp edge for the Edge Split modifier");
 	RNA_def_property_update(prop, 0, "rna_Mesh_update_data");
 
 	prop = RNA_def_property(srna, "is_loose", PROP_BOOLEAN, PROP_NONE);
@@ -3560,7 +3560,7 @@ static void rna_def_mesh(BlenderRNA *brna)
 
 	prop = RNA_def_property(srna, "show_edge_crease", PROP_BOOLEAN, PROP_NONE);
 	RNA_def_property_boolean_sdna(prop, NULL, "drawflag", ME_DRAWCREASES);
-	RNA_def_property_ui_text(prop, "Draw Creases", "Display creases created for subsurf weighting");
+	RNA_def_property_ui_text(prop, "Draw Creases", "Display creases created for Subdivision Surface modifier");
 	RNA_def_property_update(prop, 0, "rna_Mesh_update_draw");
 
 	prop = RNA_def_property(srna, "show_edge_bevel_weight", PROP_BOOLEAN, PROP_NONE);
@@ -3575,7 +3575,7 @@ static void rna_def_mesh(BlenderRNA *brna)
 
 	prop = RNA_def_property(srna, "show_edge_sharp", PROP_BOOLEAN, PROP_NONE);
 	RNA_def_property_boolean_sdna(prop, NULL, "drawflag", ME_DRAWSHARP);
-	RNA_def_property_ui_text(prop, "Draw Sharp", "Display sharp edges, used with the EdgeSplit modifier");
+	RNA_def_property_ui_text(prop, "Draw Sharp", "Display sharp edges, used with the Edge Split modifier");
 	RNA_def_property_update(prop, 0, "rna_Mesh_update_draw");
 
 	prop = RNA_def_property(srna, "show_freestyle_edge_marks", PROP_BOOLEAN, PROP_NONE);
diff --git a/source/blender/makesrna/intern/rna_mesh_api.c b/source/blender/makesrna/intern/rna_mesh_api.c
index 4a078ef9182..cd48bc1a3df 100644
--- a/source/blender/makesrna/intern/rna_mesh_api.c
+++ b/source/blender/makesrna/intern/rna_mesh_api.c
@@ -240,6 +240,9 @@ void RNA_api_mesh(StructRNA *srna)
 	func = RNA_def_function(srna, "free_normals_split", "rna_Mesh_free_normals_split");
 	RNA_def_function_ui_description(func, "Free split vertex normals");
 
+	func = RNA_def_function(srna, "split_faces", "BKE_mesh_split_faces");
+	RNA_def_function_ui_description(func, "Spli faces based on the edge angle");
+
 	func = RNA_def_function(srna, "calc_tangents", "rna_Mesh_calc_tangents");
 	RNA_def_function_flag(func, FUNC_USE_REPORTS);
 	RNA_def_function_ui_description(func,
diff --git a/source/blender/makesrna/intern/rna_nla.c b/source/blender/makesrna/intern/rna_nla.c
index 078f6e237f0..e44a6420045 100644
--- a/source/blender/makesrna/intern/rna_nla.c
+++ b/source/blender/makesrna/intern/rna_nla.c
@@ -663,7 +663,10 @@ static void rna_def_nlastrip(BlenderRNA *brna)
 	
 	prop = RNA_def_property(srna, "strip_time", PROP_FLOAT, PROP_TIME);
 	RNA_def_property_ui_text(prop, "Strip Time", "Frame of referenced Action to evaluate");
-	RNA_def_property_update(prop, NC_ANIMATION | ND_NLA | NA_EDITED, "rna_NlaStrip_update");
+	/* XXX: Update temporarily disabled so that the property can be edited at all!
+	 * Even autokey only applies after the curves have been re-evaluated, causing the unkeyed values to be lost
+	 */
+	RNA_def_property_update(prop, NC_ANIMATION | ND_NLA | NA_EDITED, /*"rna_NlaStrip_update"*/ NULL);
 	
 	/* TODO: should the animated_influence/time settings be animatable themselves? */
 	prop = RNA_def_property(srna, "use_animated_influence", PROP_BOOLEAN, PROP_NONE);
diff --git a/source/blender/makesrna/intern/rna_sequencer.c b/source/blender/makesrna/intern/rna_sequencer.c
index ae444acc432..3e6d8441363 100644
--- a/source/blender/makesrna/intern/rna_sequencer.c
+++ b/source/blender/makesrna/intern/rna_sequencer.c
@@ -1674,7 +1674,7 @@ static void rna_def_filter_video(StructRNA *srna)
 
 	prop = RNA_def_property(srna, "use_deinterlace", PROP_BOOLEAN, PROP_NONE);
 	RNA_def_property_boolean_sdna(prop, NULL, "flag", SEQ_FILTERY);
-	RNA_def_property_ui_text(prop, "De-Interlace", "For video movies to remove fields");
+	RNA_def_property_ui_text(prop, "Deinterlace", "Remove fields from video movies");
 	RNA_def_property_update(prop, NC_SCENE | ND_SEQUENCER, "rna_Sequence_update_reopen_files");
 
 	prop = RNA_def_property(srna, "alpha_mode", PROP_ENUM, PROP_NONE);
diff --git a/source/blender/makesrna/intern/rna_space.c b/source/blender/makesrna/intern/rna_space.c
index 1feae9e0bca..5e364a3adf1 100644
--- a/source/blender/makesrna/intern/rna_space.c
+++ b/source/blender/makesrna/intern/rna_space.c
@@ -2624,7 +2624,7 @@ static void rna_def_space_view3d(BlenderRNA *brna)
 	
 	prop = RNA_def_property(srna, "use_pivot_point_align", PROP_BOOLEAN, PROP_NONE);
 	RNA_def_property_boolean_sdna(prop, NULL, "flag", V3D_ALIGN);
-	RNA_def_property_ui_text(prop, "Align", "Manipulate center points (object and pose mode only)");
+	RNA_def_property_ui_text(prop, "Align", "Manipulate center points (object, pose and weight paint mode only)");
 	RNA_def_property_ui_icon(prop, ICON_ALIGN, 0);
 	RNA_def_property_update(prop, NC_SPACE | ND_SPACE_VIEW3D, "rna_SpaceView3D_pivot_update");
 
diff --git a/source/blender/makesrna/intern/rna_userdef.c b/source/blender/makesrna/intern/rna_userdef.c
index beb1d890ba9..e68e67586e9 100644
--- a/source/blender/makesrna/intern/rna_userdef.c
+++ b/source/blender/makesrna/intern/rna_userdef.c
@@ -3287,7 +3287,7 @@ static void rna_def_userdef_walk_navigation(BlenderRNA *brna)
 
 	prop = RNA_def_property(srna, "use_mouse_reverse", PROP_BOOLEAN, PROP_BOOLEAN);
 	RNA_def_property_boolean_sdna(prop, NULL, "flag", USER_WALK_MOUSE_REVERSE);
-	RNA_def_property_ui_text(prop, "Reverse Mouse", "Reverse the mouse look");
+	RNA_def_property_ui_text(prop, "Reverse Mouse", "Reverse the vertical movement of the mouse");
 }
 
 static void rna_def_userdef_view(BlenderRNA *brna)
@@ -4332,7 +4332,7 @@ static void rna_def_userdef_input(BlenderRNA *brna)
 
 	prop = RNA_def_property(srna, "ndof_deadzone", PROP_FLOAT, PROP_FACTOR);
 	RNA_def_property_range(prop, 0.0f, 1.0f);
-	RNA_def_property_ui_text(prop, "Deadzone", "Deadzone of the 3D Mouse");
+	RNA_def_property_ui_text(prop, "Deadzone", "Threshold of initial movement needed from the device's rest position");
 	RNA_def_property_update(prop, 0, "rna_userdef_ndof_deadzone_update");
 
 	prop = RNA_def_property(srna, "ndof_pan_yz_swap_axis", PROP_BOOLEAN, PROP_NONE);
diff --git a/source/blender/python/intern/bpy_rna_anim.c b/source/blender/python/intern/bpy_rna_anim.c
index 92931eb8090..8a0130babd5 100644
--- a/source/blender/python/intern/bpy_rna_anim.c
+++ b/source/blender/python/intern/bpy_rna_anim.c
@@ -36,12 +36,15 @@
 
 #include "DNA_scene_types.h"
 #include "DNA_anim_types.h"
+
 #include "ED_keyframing.h"
+#include "ED_keyframes_edit.h"
 
 #include "BKE_report.h"
 #include "BKE_context.h"
 #include "BKE_animsys.h"
 #include "BKE_fcurve.h"
+#include "BKE_idcode.h"
 
 #include "RNA_access.h"
 #include "RNA_enum_types.h"
@@ -223,9 +226,47 @@ PyObject *pyrna_struct_keyframe_insert(BPy_StructRNA *self, PyObject *args, PyOb
 	{
 		return NULL;
 	}
+	else if (self->ptr.type == &RNA_NlaStrip) {
+		/* Handle special properties for NLA Strips, whose F-Curves are stored on the
+		 * strips themselves. These are stored separately or else the properties will
+		 * not have any effect.
+		 */
+		ReportList reports;
+		short result = 0;
+		
+		PointerRNA ptr = self->ptr;
+		PropertyRNA *prop = NULL;
+		const char *prop_name;
+		
+		BKE_reports_init(&reports, RPT_STORE);
+		
+		/* Retrieve the property identifier from the full path, since we can't get it any other way */
+		prop_name = strrchr(path_full, '.');
+		if ((prop_name >= path_full) &&
+		    (prop_name + 1 < path_full + strlen(path_full)))
+		{
+			prop = RNA_struct_find_property(&ptr, prop_name + 1);
+		}
+		
+		if (prop) {
+			NlaStrip *strip = (NlaStrip *)ptr.data;
+			FCurve *fcu = list_find_fcurve(&strip->fcurves, RNA_property_identifier(prop), index);
+			
+			result = insert_keyframe_direct(&reports, ptr, prop, fcu, cfra, keytype, options);
+		}
+		else {
+			BKE_reportf(&reports, RPT_ERROR, "Could not resolve path (%s)", path_full);
+		}
+		MEM_freeN((void *)path_full);
+		
+		if (BPy_reports_to_error(&reports, PyExc_RuntimeError, true) == -1)
+			return NULL;
+		
+		return PyBool_FromLong(result);
+	}
 	else {
-		short result;
 		ReportList reports;
+		short result;
 
 		BKE_reports_init(&reports, RPT_STORE);
 
@@ -272,6 +313,67 @@ PyObject *pyrna_struct_keyframe_delete(BPy_StructRNA *self, PyObject *args, PyOb
 	{
 		return NULL;
 	}
+	else if (self->ptr.type == &RNA_NlaStrip) {
+		/* Handle special properties for NLA Strips, whose F-Curves are stored on the
+		 * strips themselves. These are stored separately or else the properties will
+		 * not have any effect.
+		 */
+		ReportList reports;
+		short result = 0;
+		
+		PointerRNA ptr = self->ptr;
+		PropertyRNA *prop = NULL;
+		const char *prop_name;
+		
+		BKE_reports_init(&reports, RPT_STORE);
+		
+		/* Retrieve the property identifier from the full path, since we can't get it any other way */
+		prop_name = strrchr(path_full, '.');
+		if ((prop_name >= path_full) &&
+		    (prop_name + 1 < path_full + strlen(path_full)))
+		{
+			prop = RNA_struct_find_property(&ptr, prop_name + 1);
+		}
+		
+		if (prop) {
+			ID *id = ptr.id.data;
+			NlaStrip *strip = (NlaStrip *)ptr.data;
+			FCurve *fcu = list_find_fcurve(&strip->fcurves, RNA_property_identifier(prop), index);
+			
+			BLI_assert(fcu != NULL); /* NOTE: This should be true, or else we wouldn't be able to get here */
+			
+			if (BKE_fcurve_is_protected(fcu)) {
+				BKE_reportf(&reports, RPT_WARNING,
+				            "Not deleting keyframe for locked F-Curve for NLA Strip influence on %s - %s '%s'",
+				            strip->name, BKE_idcode_to_name(GS(id->name)), id->name + 2);
+			}
+			else {
+				/* remove the keyframe directly
+				 * NOTE: cannot use delete_keyframe_fcurve(), as that will free the curve,
+				 *       and delete_keyframe() expects the FCurve to be part of an action
+				 */
+				bool found = false;
+				int i;
+				
+				/* try to find index of beztriple to get rid of */
+				i = binarysearch_bezt_index(fcu->bezt, cfra, fcu->totvert, &found);
+				if (found) {
+					/* delete the key at the index (will sanity check + do recalc afterwards) */
+					delete_fcurve_key(fcu, i, 1);
+					result = true;
+				}
+			}
+		}
+		else {
+			BKE_reportf(&reports, RPT_ERROR, "Could not resolve path (%s)", path_full);
+		}
+		MEM_freeN((void *)path_full);
+		
+		if (BPy_reports_to_error(&reports, PyExc_RuntimeError, true) == -1)
+			return NULL;
+		
+		return PyBool_FromLong(result);
+	}
 	else {
 		short result;
 		ReportList reports;
diff --git a/source/blender/render/intern/source/convertblender.c b/source/blender/render/intern/source/convertblender.c
index 86961cdd169..263ea3d4ef2 100644
--- a/source/blender/render/intern/source/convertblender.c
+++ b/source/blender/render/intern/source/convertblender.c
@@ -5569,12 +5569,17 @@ static void calculate_speedvectors(Render *re, ObjectInstanceRen *obi, float *ve
 					/* interpolate speed vectors from strand surface */
 					face= mesh->face[*index];
 
-					co1= mesh->co[face[0]];
-					co2= mesh->co[face[1]];
-					co3= mesh->co[face[2]];
-					co4= (face[3])? mesh->co[face[3]]: NULL;
+					co1 = mesh->co[face[0]];
+					co2 = mesh->co[face[1]];
+					co3 = mesh->co[face[2]];
 
-					interp_weights_face_v3(w, co1, co2, co3, co4, strand->vert->co);
+					if (face[3]) {
+						co4 = mesh->co[face[3]];
+						interp_weights_quad_v3(w, co1, co2, co3, co4, strand->vert->co);
+					}
+					else {
+						interp_weights_tri_v3(w, co1, co2, co3, strand->vert->co);
+					}
 
 					zero_v4(speed);
 					madd_v4_v4fl(speed, winspeed[face[0]], w[0]);
diff --git a/source/blender/render/intern/source/occlusion.c b/source/blender/render/intern/source/occlusion.c
index b3d31e3b93a..cd93898d846 100644
--- a/source/blender/render/intern/source/occlusion.c
+++ b/source/blender/render/intern/source/occlusion.c
@@ -329,7 +329,7 @@ static void occ_face(const OccFace *face, float co[3], float normal[3], float *a
 		if (vlr->v4)
 			mid_v3_v3v3(co, vlr->v1->co, vlr->v3->co);
 		else
-			cent_tri_v3(co, vlr->v1->co, vlr->v2->co, vlr->v3->co);
+			mid_v3_v3v3v3(co, vlr->v1->co, vlr->v2->co, vlr->v3->co);
 
 		if (obi->flag & R_TRANSFORMED)
 			mul_m4_v3(obi->mat, co);
@@ -1190,9 +1190,14 @@ static void sample_occ_surface(ShadeInput *shi)
 		co1 = mesh->co[face[0]];
 		co2 = mesh->co[face[1]];
 		co3 = mesh->co[face[2]];
-		co4 = (face[3]) ? mesh->co[face[3]] : NULL;
 
-		interp_weights_face_v3(w, co1, co2, co3, co4, strand->vert->co);
+		if (face[3]) {
+			co4 = mesh->co[face[3]];
+			interp_weights_quad_v3(w, co1, co2, co3, co4, strand->vert->co);
+		}
+		else {
+			interp_weights_tri_v3(w, co1, co2, co3, strand->vert->co);
+		}
 
 		zero_v3(shi->ao);
 		zero_v3(shi->env);
@@ -1245,7 +1250,7 @@ static void *exec_strandsurface_sample(void *data)
 			normal_quad_v3(n, co1, co2, co3, co4);
 		}
 		else {
-			cent_tri_v3(co, co1, co2, co3);
+			mid_v3_v3v3v3(co, co1, co2, co3);
 			normal_tri_v3(n, co1, co2, co3);
 		}
 		negate_v3(n);
diff --git a/source/blender/render/intern/source/pipeline.c b/source/blender/render/intern/source/pipeline.c
index 98cd95ebefb..6d74e521aca 100644
--- a/source/blender/render/intern/source/pipeline.c
+++ b/source/blender/render/intern/source/pipeline.c
@@ -74,6 +74,7 @@
 #include "BKE_report.h"
 #include "BKE_scene.h"
 #include "BKE_sequencer.h"
+#include "BKE_sound.h"
 #include "BKE_writeavi.h"  /* <------ should be replaced once with generic movie module */
 #include "BKE_object.h"
 
@@ -3795,6 +3796,7 @@ void RE_BlenderAnim(Render *re, Main *bmain, Scene *scene, Object *camera_overri
 	re->flag &= ~R_ANIMATION;
 
 	BLI_callback_exec(re->main, (ID *)scene, G.is_break ? BLI_CB_EVT_RENDER_CANCEL : BLI_CB_EVT_RENDER_COMPLETE);
+	BKE_sound_reset_scene_specs(scene);
 
 	/* UGLY WARNING */
 	G.is_rendering = false;
diff --git a/source/blender/windowmanager/intern/wm_draw.c b/source/blender/windowmanager/intern/wm_draw.c
index 3825db14e93..77ffa46b990 100644
--- a/source/blender/windowmanager/intern/wm_draw.c
+++ b/source/blender/windowmanager/intern/wm_draw.c
@@ -430,7 +430,7 @@ static int wm_triple_gen_textures(wmWindow *win, wmDrawTriple *triple)
 	return 1;
 }
 
-void wm_triple_draw_textures(wmWindow *win, wmDrawTriple *triple, float alpha)
+void wm_triple_draw_textures(wmWindow *win, wmDrawTriple *triple, float alpha, bool is_interlace)
 {
 	const int sizex = WM_window_pixels_x(win);
 	const int sizey = WM_window_pixels_y(win);
@@ -451,7 +451,13 @@ void wm_triple_draw_textures(wmWindow *win, wmDrawTriple *triple, float alpha)
 		halfy /= triple->y;
 	}
 
-	GPU_basic_shader_bind((triple->target == GL_TEXTURE_2D) ? GPU_SHADER_TEXTURE_2D : GPU_SHADER_TEXTURE_RECT);
+	/* interlace stereo buffer bind the shader before calling wm_triple_draw_textures */
+	if (is_interlace) {
+		glEnable(triple->target);
+	}
+	else {
+		GPU_basic_shader_bind((triple->target == GL_TEXTURE_2D) ? GPU_SHADER_TEXTURE_2D : GPU_SHADER_TEXTURE_RECT);
+	}
 
 	glBindTexture(triple->target, triple->bind);
 
@@ -472,7 +478,12 @@ void wm_triple_draw_textures(wmWindow *win, wmDrawTriple *triple, float alpha)
 
 	glBindTexture(triple->target, 0);
 
-	GPU_basic_shader_bind(GPU_SHADER_USE_COLOR);
+	if (is_interlace) {
+		glDisable(triple->target);
+	}
+	else {
+		GPU_basic_shader_bind(GPU_SHADER_USE_COLOR);
+	}
 }
 
 static void wm_triple_copy_textures(wmWindow *win, wmDrawTriple *triple)
@@ -495,7 +506,7 @@ static void wm_draw_region_blend(wmWindow *win, ARegion *ar, wmDrawTriple *tripl
 		wmSubWindowScissorSet(win, win->screen->mainwin, &ar->winrct, true);
 
 		glEnable(GL_BLEND);
-		wm_triple_draw_textures(win, triple, 1.0f - fac);
+		wm_triple_draw_textures(win, triple, 1.0f - fac, false);
 		glDisable(GL_BLEND);
 	}
 }
@@ -516,7 +527,7 @@ static void wm_method_draw_triple(bContext *C, wmWindow *win)
 
 		wmSubWindowSet(win, screen->mainwin);
 
-		wm_triple_draw_textures(win, drawdata->triple, 1.0f);
+		wm_triple_draw_textures(win, drawdata->triple, 1.0f, false);
 	}
 	else {
 		/* we run it when we start OR when we turn stereo on */
@@ -656,7 +667,7 @@ static void wm_method_draw_triple_multiview(bContext *C, wmWindow *win, StereoVi
 
 				wmSubWindowSet(win, screen->mainwin);
 
-				wm_triple_draw_textures(win, drawdata->triple, 1.0f);
+				wm_triple_draw_textures(win, drawdata->triple, 1.0f, false);
 			}
 		}
 		else {
diff --git a/source/blender/windowmanager/intern/wm_stereo.c b/source/blender/windowmanager/intern/wm_stereo.c
index 1c1c2ad35af..46cee907991 100644
--- a/source/blender/windowmanager/intern/wm_stereo.c
+++ b/source/blender/windowmanager/intern/wm_stereo.c
@@ -77,7 +77,7 @@ static void wm_method_draw_stereo3d_pageflip(wmWindow *win)
 		else //STEREO_RIGHT_ID
 			glDrawBuffer(GL_BACK_RIGHT);
 
-		wm_triple_draw_textures(win, drawdata->triple, 1.0f);
+		wm_triple_draw_textures(win, drawdata->triple, 1.0f, false);
 	}
 
 	glDrawBuffer(GL_BACK);
@@ -120,7 +120,7 @@ static void wm_method_draw_stereo3d_interlace(wmWindow *win)
 				break;
 		}
 
-		wm_triple_draw_textures(win, drawdata->triple, 1.0f);
+		wm_triple_draw_textures(win, drawdata->triple, 1.0f, true);
 		GPU_basic_shader_bind(GPU_SHADER_USE_COLOR);
 	}
 	interlace_prev_type = interlace_type;
@@ -157,7 +157,7 @@ static void wm_method_draw_stereo3d_anaglyph(wmWindow *win)
 				break;
 		}
 
-		wm_triple_draw_textures(win, drawdata->triple, 1.0f);
+		wm_triple_draw_textures(win, drawdata->triple, 1.0f, false);
 
 		glColorMask(GL_TRUE, GL_TRUE, GL_TRUE, GL_TRUE);
 	}
diff --git a/source/blender/windowmanager/wm_draw.h b/source/blender/windowmanager/wm_draw.h
index 0f125309045..5257bba45ff 100644
--- a/source/blender/windowmanager/wm_draw.h
+++ b/source/blender/windowmanager/wm_draw.h
@@ -56,7 +56,7 @@ void		wm_draw_region_clear	(struct wmWindow *win, struct ARegion *ar);
 
 void		wm_tag_redraw_overlay	(struct wmWindow *win, struct ARegion *ar);
 
-void		wm_triple_draw_textures	(struct wmWindow *win, struct wmDrawTriple *triple, float alpha);
+void		wm_triple_draw_textures	(struct wmWindow *win, struct wmDrawTriple *triple, float alpha, bool is_interlace);
 
 void		wm_draw_data_free		(struct wmWindow *win);
 
diff --git a/source/blenderplayer/bad_level_call_stubs/stubs.c b/source/blenderplayer/bad_level_call_stubs/stubs.c
index 5f4d0eae483..1d162812e8c 100644
--- a/source/blenderplayer/bad_level_call_stubs/stubs.c
+++ b/source/blenderplayer/bad_level_call_stubs/stubs.c
@@ -674,7 +674,7 @@ void RE_point_density_sample(struct Scene *scene, struct PointDensity *pd, int r
 void RE_point_density_free(struct PointDensity *pd) RET_NONE;
 void RE_instance_get_particle_info(struct ObjectInstanceRen *obi, float *index, float *age, float *lifetime, float co[3], float *size, float vel[3], float angvel[3]) RET_NONE
 void RE_FreeAllPersistentData(void) RET_NONE
-float RE_fresnel_dielectric(float incoming[3], float normal[3], float eta) RET_NONE
+float RE_fresnel_dielectric(float incoming[3], float normal[3], float eta) RET_ZERO
 
 /* python */
 struct wmOperatorType *WM_operatortype_find(const char *idname, bool quiet) RET_NULL
diff --git a/source/creator/creator_args.c b/source/creator/creator_args.c
index 9f845d29c18..4eb72fb1619 100644
--- a/source/creator/creator_args.c
+++ b/source/creator/creator_args.c
@@ -1886,7 +1886,7 @@ void main_args_setup(bContext *C, bArgs *ba, SYS_SystemHandle *syshandle)
 	BLI_argsAdd(ba, 4, "-E", "--engine", CB(arg_handle_engine_set), C);
 
 	BLI_argsAdd(ba, 4, "-F", "--render-format", CB(arg_handle_image_type_set), C);
-	BLI_argsAdd(ba, 4, "-t", "--threads", CB(arg_handle_threads_set), NULL);
+	BLI_argsAdd(ba, 1, "-t", "--threads", CB(arg_handle_threads_set), NULL);
 	BLI_argsAdd(ba, 4, "-x", "--use-extension", CB(arg_handle_extension_set), C);
 
 #undef CB
diff --git a/tests/gtests/blenlib/BLI_string_utf8_test.cc b/tests/gtests/blenlib/BLI_string_utf8_test.cc
new file mode 100644
index 00000000000..c0beb92eeec
--- /dev/null
+++ b/tests/gtests/blenlib/BLI_string_utf8_test.cc
@@ -0,0 +1,304 @@
+/* Apache License, Version 2.0 */
+
+#include "testing/testing.h"
+
+extern "C" {
+#include "BLI_utildefines.h"
+#include "BLI_string.h"
+#include "BLI_string_utf8.h"
+}
+
+/* Note that 'common' utf-8 variants of string functions (like copy, etc.) are tested in BLI_string_test.cc
+ * However, tests below are specific utf-8 conformance ones, and since they eat quite their share of lines,
+ * they deserved their own file. */
+
+/* -------------------------------------------------------------------- */
+/* stubs */
+
+extern "C" {
+
+int mk_wcwidth(wchar_t ucs);
+int mk_wcswidth(const wchar_t *pwcs, size_t n);
+
+int mk_wcwidth(wchar_t ucs)
+{
+	return 0;
+}
+
+int mk_wcswidth(const wchar_t *pwcs, size_t n)
+{
+	return 0;
+}
+
+}
+
+/* -------------------------------------------------------------------- */
+/* tests */
+
+/* Each test is made of a 79 bytes (80 with NULL char) string to test, expected string result after
+ * stripping invalid utf8 bytes, and a single-byte string encoded with expected number of errors.
+ *
+ * Based on utf-8 decoder stress-test (https://www.cl.cam.ac.uk/~mgk25/ucs/examples/UTF-8-test.txt)
+ *     by Markus Kuhn <http://www.cl.cam.ac.uk/~mgk25/> - 2015-08-28 - CC BY 4.0
+ */
+const char *utf8_invalid_tests[][3] = {
+//    1  Some correct UTF-8 text
+    {"You should see the Greek word 'kosme':       \"\xce\xba\xe1\xbd\xb9\xcf\x83\xce\xbc\xce\xb5\"                    |",
+     "You should see the Greek word 'kosme':       \"\xce\xba\xe1\xbd\xb9\xcf\x83\xce\xbc\xce\xb5\"                    |", "\x00"},
+
+//    2  Boundary condition test cases
+//    Note that those will pass for us, those are not erronéous unicode code points
+//    (asside from \x00, which is only valid as string terminator).
+//    2.1  First possible sequence of a certain length
+    {"2.1.1  1 byte  (U-00000000):        \"\x00\"                                       |",
+     "2.1.1  1 byte  (U-00000000):        \"\"                                       |", "\x01"},
+    {"2.1.2  2 bytes (U-00000080):        \"\xc2\x80\"                                      |",
+     "2.1.2  2 bytes (U-00000080):        \"\xc2\x80\"                                      |", "\x00"},
+    {"2.1.3  3 bytes (U-00000800):        \"\xe0\xa0\x80\"                                     |",
+     "2.1.3  3 bytes (U-00000800):        \"\xe0\xa0\x80\"                                     |", "\x00"},
+    {"2.1.4  4 bytes (U-00010000):        \"\xf0\x90\x80\x80\"                                    |",
+     "2.1.4  4 bytes (U-00010000):        \"\xf0\x90\x80\x80\"                                    |", "\x00"},
+    {"2.1.5  5 bytes (U-00200000):        \"\xf8\x88\x80\x80\x80\"                                   |",
+     "2.1.5  5 bytes (U-00200000):        \"\xf8\x88\x80\x80\x80\"                                   |", "\x00"},
+    {"2.1.6  6 bytes (U-04000000):        \"\xfc\x84\x80\x80\x80\x80\"                                  |",
+     "2.1.6  6 bytes (U-04000000):        \"\xfc\x84\x80\x80\x80\x80\"                                  |", "\x00"},
+//    2.2  Last possible sequence of a certain length
+    {"2.2.1  1 byte  (U-0000007F):        \"\x7f\"                                       |",
+     "2.2.1  1 byte  (U-0000007F):        \"\x7f\"                                       |", "\x00"},
+    {"2.2.2  2 bytes (U-000007FF):        \"\xdf\xbf\"                                      |",
+     "2.2.2  2 bytes (U-000007FF):        \"\xdf\xbf\"                                      |", "\x00"},
+    {"2.2.3  3 bytes (U-0000FFFF):        \"\xef\xbf\xbf\"                                     |",
+     "2.2.3  3 bytes (U-0000FFFF):        \"\"                                     |", "\x03"},  /* matches one of 5.3 sequences... */
+    {"2.2.4  4 bytes (U-001FFFFF):        \"\xf7\xbf\xbf\xbf\"                                    |",
+     "2.2.4  4 bytes (U-001FFFFF):        \"\xf7\xbf\xbf\xbf\"                                    |", "\x00"},
+    {"2.2.5  5 bytes (U-03FFFFFF):        \"\xfb\xbf\xbf\xbf\xbf\"                                   |",
+     "2.2.5  5 bytes (U-03FFFFFF):        \"\xfb\xbf\xbf\xbf\xbf\"                                   |", "\x00"},
+    {"2.2.6  6 bytes (U-7FFFFFFF):        \"\xfd\xbf\xbf\xbf\xbf\xbf\"                                  |",
+     "2.2.6  6 bytes (U-7FFFFFFF):        \"\xfd\xbf\xbf\xbf\xbf\xbf\"                                  |", "\x00"},
+//    2.3  Other boundary conditions
+    {"2.3.1  U-0000D7FF = ed 9f bf = \"\xed\x9f\xbf\"                                          |",
+     "2.3.1  U-0000D7FF = ed 9f bf = \"\xed\x9f\xbf\"                                          |", "\x00"},
+    {"2.3.2  U-0000E000 = ee 80 80 = \"\xee\x80\x80\"                                          |",
+     "2.3.2  U-0000E000 = ee 80 80 = \"\xee\x80\x80\"                                          |", "\x00"},
+    {"2.3.3  U-0000FFFD = ef bf bd = \"\xef\xbf\xbd\"                                          |",
+     "2.3.3  U-0000FFFD = ef bf bd = \"\xef\xbf\xbd\"                                          |", "\x00"},
+    {"2.3.4  U-0010FFFF = f4 8f bf bf = \"\xf4\x8f\xbf\xbf\"                                      |",
+     "2.3.4  U-0010FFFF = f4 8f bf bf = \"\xf4\x8f\xbf\xbf\"                                      |", "\x00"},
+    {"2.3.5  U-00110000 = f4 90 80 80 = \"\xf4\x90\x80\x80\"                                      |",
+     "2.3.5  U-00110000 = f4 90 80 80 = \"\xf4\x90\x80\x80\"                                      |", "\x00"},
+
+//    3  Malformed sequences
+//    3.1  Unexpected continuation bytes
+//         Each unexpected continuation byte should be separately signalled as a malformed sequence of its own.
+    {"3.1.1  First continuation byte 0x80: \"\x80\"                                      |",
+     "3.1.1  First continuation byte 0x80: \"\"                                      |", "\x01"},
+    {"3.1.2  Last  continuation byte 0xbf: \"\xbf\"                                      |",
+     "3.1.2  Last  continuation byte 0xbf: \"\"                                      |", "\x01"},
+    {"3.1.3  2 continuation bytes: \"\x80\xbf\"                                             |",
+     "3.1.3  2 continuation bytes: \"\"                                             |", "\x02"},
+    {"3.1.4  3 continuation bytes: \"\x80\xbf\x80\"                                            |",
+     "3.1.4  3 continuation bytes: \"\"                                            |", "\x03"},
+    {"3.1.5  4 continuation bytes: \"\x80\xbf\x80\xbf\"                                           |",
+     "3.1.5  4 continuation bytes: \"\"                                           |", "\x04"},
+    {"3.1.6  5 continuation bytes: \"\x80\xbf\x80\xbf\x80\"                                          |",
+     "3.1.6  5 continuation bytes: \"\"                                          |", "\x05"},
+    {"3.1.7  6 continuation bytes: \"\x80\xbf\x80\xbf\x80\xbf\"                                         |",
+     "3.1.7  6 continuation bytes: \"\"                                         |", "\x06"},
+    {"3.1.8  7 continuation bytes: \"\x80\xbf\x80\xbf\x80\xbf\x80\"                                        |",
+     "3.1.8  7 continuation bytes: \"\"                                        |", "\x07"},
+//    3.1.9  Sequence of all 64 possible continuation bytes (0x80-0xbf):            |
+    {"3.1.9      \"\x80\x81\x82\x83\x84\x85\x86\x87\x88\x89\x8a\x8b\x8c\x8d\x8e\x8f"
+                  "\x90\x91\x92\x93\x94\x95\x96\x97\x98\x99\x9a\x9b\x9c\x9d\x9e\x9f"
+                  "\xa0\xa1\xa2\xa3\xa4\xa5\xa6\xa7\xa8\xa9\xaa\xab\xac\xad\xae\xaf"
+                  "\xb0\xb1\xb2\xb3\xb4\xb5\xb6\xb7\xb8\xb9\xba\xbb\xbc\xbd\xbe\xbf\" |",
+     "3.1.9      \"\" |", "\x40"},
+//    3.2  Lonely start characters
+//    3.2.1  All 32 first bytes of 2-byte sequences (0xc0-0xdf), each followed by a space character:
+    {"3.2.1      \"\xc0 \xc1 \xc2 \xc3 \xc4 \xc5 \xc6 \xc7 \xc8 \xc9 \xca \xcb \xcc \xcd \xce \xcf "
+                  "\xd0 \xd1 \xd2 \xd3 \xd4 \xd5 \xd6 \xd7 \xd8 \xd9 \xda \xdb \xdc \xdd \xde \xdf \" |",
+     "3.2.1      \"                                \" |", "\x20"},
+//    3.2.2  All 16 first bytes of 3-byte sequences (0xe0-0xef), each followed by a space character:
+    {"3.2.2      \"\xe0 \xe1 \xe2 \xe3 \xe4 \xe5 \xe6 \xe7 \xe8 \xe9 \xea \xeb \xec \xed \xee \xef \"                                 |",
+     "3.2.2      \"                \"                                 |", "\x10"},
+//    3.2.3  All 8 first bytes of 4-byte sequences (0xf0-0xf7), each followed by a space character:
+    {"3.2.3      \"\xf0 \xf1 \xf2 \xf3 \xf4 \xf5 \xf6 \xf7 \"                                                 |",
+     "3.2.3      \"        \"                                                 |", "\x08"},
+//    3.2.4  All 4 first bytes of 5-byte sequences (0xf8-0xfb), each followed by a space character:
+    {"3.2.4      \"\xf8 \xf9 \xfa \xfb \"                                                         |",
+     "3.2.4      \"    \"                                                         |", "\x04"},
+//    3.2.5  All 2 first bytes of 6-byte sequences (0xfc-0xfd), each followed by a space character:
+    {"3.2.4      \"\xfc \xfd \"                                                             |",
+     "3.2.4      \"  \"                                                             |", "\x02"},
+//    3.3  Sequences with last continuation byte missing
+//         All bytes of an incomplete sequence should be signalled as a single malformed sequence,
+//         i.e., you should see only a single replacement character in each of the next 10 tests.
+//         (Characters as in section 2)
+    {"3.3.1  2-byte sequence with last byte missing (U+0000):     \"\xc0\"               |",
+     "3.3.1  2-byte sequence with last byte missing (U+0000):     \"\"               |", "\x01"},
+    {"3.3.2  3-byte sequence with last byte missing (U+0000):     \"\xe0\x80\"              |",
+     "3.3.2  3-byte sequence with last byte missing (U+0000):     \"\"              |", "\x02"},
+    {"3.3.3  4-byte sequence with last byte missing (U+0000):     \"\xf0\x80\x80\"             |",
+     "3.3.3  4-byte sequence with last byte missing (U+0000):     \"\"             |", "\x03"},
+    {"3.3.4  5-byte sequence with last byte missing (U+0000):     \"\xf8\x80\x80\x80\"            |",
+     "3.3.4  5-byte sequence with last byte missing (U+0000):     \"\"            |", "\x04"},
+    {"3.3.5  6-byte sequence with last byte missing (U+0000):     \"\xfc\x80\x80\x80\x80\"           |",
+     "3.3.5  6-byte sequence with last byte missing (U+0000):     \"\"           |", "\x05"},
+    {"3.3.6  2-byte sequence with last byte missing (U-000007FF): \"\xdf\"               |",
+     "3.3.6  2-byte sequence with last byte missing (U-000007FF): \"\"               |", "\x01"},
+    {"3.3.7  3-byte sequence with last byte missing (U-0000FFFF): \"\xef\xbf\"              |",
+     "3.3.7  3-byte sequence with last byte missing (U-0000FFFF): \"\"              |", "\x02"},
+    {"3.3.8  4-byte sequence with last byte missing (U-001FFFFF): \"\xf7\xbf\xbf\"             |",
+     "3.3.8  4-byte sequence with last byte missing (U-001FFFFF): \"\"             |", "\x03"},
+    {"3.3.9  5-byte sequence with last byte missing (U-03FFFFFF): \"\xfb\xbf\xbf\xbf\"            |",
+     "3.3.9  5-byte sequence with last byte missing (U-03FFFFFF): \"\"            |", "\x04"},
+    {"3.3.10 6-byte sequence with last byte missing (U-7FFFFFFF): \"\xfd\xbf\xbf\xbf\xbf\"           |",
+     "3.3.10 6-byte sequence with last byte missing (U-7FFFFFFF): \"\"           |", "\x05"},
+//    3.4  Concatenation of incomplete sequences
+//         All the 10 sequences of 3.3 concatenated, you should see 10 malformed sequences being signalled:
+    {"3.4      \"\xc0\xe0\x80\xf0\x80\x80\xf8\x80\x80\x80\xfc\x80\x80\x80\x80"
+                "\xdf\xef\xbf\xf7\xbf\xbf\xfb\xbf\xbf\xbf\xfd\xbf\xbf\xbf\xbf\""
+                "                                     |",
+     "3.4      \"\"                                     |", "\x1e"},
+//    3.5  Impossible bytes
+//         The following two bytes cannot appear in a correct UTF-8 string
+    {"3.5.1  fe = \"\xfe\"                                                               |",
+     "3.5.1  fe = \"\"                                                               |", "\x01"},
+    {"3.5.2  ff = \"\xff\"                                                               |",
+     "3.5.2  ff = \"\"                                                               |", "\x01"},
+    {"3.5.3  fe fe ff ff = \"\xfe\xfe\xff\xff\"                                                   |",
+     "3.5.3  fe fe ff ff = \"\"                                                   |", "\x04"},
+
+//    4  Overlong sequences
+//       The following sequences are not malformed according to the letter of the Unicode 2.0 standard.
+//       However, they are longer then necessary and a correct UTF-8 encoder is not allowed to produce them.
+//       A "safe UTF-8 decoder" should reject them just like malformed sequences for two reasons:
+//       (1) It helps to debug applications if overlong sequences are not treated as valid representations
+//       of characters, because this helps to spot problems more quickly. (2) Overlong sequences provide
+//       alternative representations of characters, that could maliciously be used to bypass filters that check
+//       only for ASCII characters. For instance, a 2-byte encoded line feed (LF) would not be caught by a
+//       line counter that counts only 0x0a bytes, but it would still be processed as a line feed by an unsafe
+//       UTF-8 decoder later in the pipeline. From a security point of view, ASCII compatibility of UTF-8
+//       sequences means also, that ASCII characters are *only* allowed to be represented by ASCII bytes
+//       in the range 0x00-0x7f. To ensure this aspect of ASCII compatibility, use only "safe UTF-8 decoders"
+//       that reject overlong UTF-8 sequences for which a shorter encoding exists.
+//
+//    4.1  Examples of an overlong ASCII character
+//         With a safe UTF-8 decoder, all of the following five overlong representations of the ASCII character
+//         slash ("/") should be rejected like a malformed UTF-8 sequence, for instance by substituting it with
+//         a replacement character. If you see a slash below, you do not have a safe UTF-8 decoder!
+    {"4.1.1  U+002F     = c0 af             = \"\xc0\xaf\"                                  |",
+     "4.1.1  U+002F     = c0 af             = \"\"                                  |", "\x02"},
+    {"4.1.2  U+002F     = e0 80 af          = \"\xe0\x80\xaf\"                                 |",
+     "4.1.2  U+002F     = e0 80 af          = \"\"                                 |", "\x03"},
+    {"4.1.3  U+002F     = f0 80 80 af       = \"\xf0\x80\x80\xaf\"                                |",
+     "4.1.3  U+002F     = f0 80 80 af       = \"\"                                |", "\x04"},
+    {"4.1.4  U+002F     = f8 80 80 80 af    = \"\xf8\x80\x80\x80\xaf\"                               |",
+     "4.1.4  U+002F     = f8 80 80 80 af    = \"\"                               |", "\x05"},
+    {"4.1.5  U+002F     = fc 80 80 80 80 af = \"\xfc\x80\x80\x80\x80\xaf\"                              |",
+     "4.1.5  U+002F     = fc 80 80 80 80 af = \"\"                              |", "\x06"},
+//    4.2  Maximum overlong sequences
+//         Below you see the highest Unicode value that is still resulting in an overlong sequence if represented
+//         with the given number of bytes. This is a boundary test for safe UTF-8 decoders. All five characters
+//         should be rejected like malformed UTF-8 sequences.
+    {"4.2.1  U-0000007F = c1 bf             = \"\xc1\xbf\"                                  |",
+     "4.2.1  U-0000007F = c1 bf             = \"\"                                  |", "\x02"},
+    {"4.2.2  U-000007FF = e0 9f bf          = \"\xe0\x9f\xbf\"                                 |",
+     "4.2.2  U-000007FF = e0 9f bf          = \"\"                                 |", "\x03"},
+    {"4.2.3  U-0000FFFF = f0 8f bf bf       = \"\xf0\x8f\xbf\xbf\"                                |",
+     "4.2.3  U-0000FFFF = f0 8f bf bf       = \"\"                                |", "\x04"},
+    {"4.2.4  U-001FFFFF = f8 87 bf bf bf    = \"\xf8\x87\xbf\xbf\xbf\"                               |",
+     "4.2.4  U-001FFFFF = f8 87 bf bf bf    = \"\"                               |", "\x05"},
+    {"4.2.5  U+0000     = fc 83 bf bf bf bf = \"\xfc\x83\xbf\xbf\xbf\xbf\"                              |",
+     "4.2.5  U+0000     = fc 83 bf bf bf bf = \"\"                              |", "\x06"},
+//    4.3  Overlong representation of the NUL character
+//         The following five sequences should also be rejected like malformed UTF-8 sequences and should not be
+//         treated like the ASCII NUL character.
+    {"4.3.1  U+0000     = c0 80             = \"\xc0\x80\"                                  |",
+     "4.3.1  U+0000     = c0 80             = \"\"                                  |", "\x02"},
+    {"4.3.2  U+0000     = e0 80 80          = \"\xe0\x80\x80\"                                 |",
+     "4.3.2  U+0000     = e0 80 80          = \"\"                                 |", "\x03"},
+    {"4.3.3  U+0000     = f0 80 80 80       = \"\xf0\x80\x80\x80\"                                |",
+     "4.3.3  U+0000     = f0 80 80 80       = \"\"                                |", "\x04"},
+    {"4.3.4  U+0000     = f8 80 80 80 80    = \"\xf8\x80\x80\x80\x80\"                               |",
+     "4.3.4  U+0000     = f8 80 80 80 80    = \"\"                               |", "\x05"},
+    {"4.3.5  U+0000     = fc 80 80 80 80 80 = \"\xfc\x80\x80\x80\x80\x80\"                              |",
+     "4.3.5  U+0000     = fc 80 80 80 80 80 = \"\"                              |", "\x06"},
+
+//    5  Illegal code positions
+//       The following UTF-8 sequences should be rejected like malformed sequences, because they never represent
+//       valid ISO 10646 characters and a UTF-8 decoder that accepts them might introduce security problems
+//       comparable to overlong UTF-8 sequences.
+//    5.1 Single UTF-16 surrogates
+    {"5.1.1  U+D800 = ed a0 80 = \"\xed\xa0\x80\"                                              |",
+     "5.1.1  U+D800 = ed a0 80 = \"\"                                              |", "\x03"},
+    {"5.1.2  U+DB7F = ed ad bf = \"\xed\xad\xbf\"                                              |",
+     "5.1.2  U+DB7F = ed ad bf = \"\"                                              |", "\x03"},
+    {"5.1.3  U+DB80 = ed ae 80 = \"\xed\xae\x80\"                                              |",
+     "5.1.3  U+DB80 = ed ae 80 = \"\"                                              |", "\x03"},
+    {"5.1.4  U+DBFF = ed af bf = \"\xed\xaf\xbf\"                                              |",
+     "5.1.4  U+DBFF = ed af bf = \"\"                                              |", "\x03"},
+    {"5.1.5  U+DC00 = ed b0 80 = \"\xed\xb0\x80\"                                              |",
+     "5.1.5  U+DC00 = ed b0 80 = \"\"                                              |", "\x03"},
+    {"5.1.6  U+DF80 = ed be 80 = \"\xed\xbe\x80\"                                              |",
+     "5.1.6  U+DF80 = ed be 80 = \"\"                                              |", "\x03"},
+    {"5.1.7  U+DFFF = ed bf bf = \"\xed\xbf\xbf\"                                              |",
+     "5.1.7  U+DFFF = ed bf bf = \"\"                                              |", "\x03"},
+//    5.2 Paired UTF-16 surrogates
+    {"5.2.1  U+D800 U+DC00 = ed a0 80 ed b0 80 = \"\xed\xa0\x80\xed\xb0\x80\"                           |",
+     "5.2.1  U+D800 U+DC00 = ed a0 80 ed b0 80 = \"\"                           |", "\x06"},
+    {"5.2.2  U+D800 U+DFFF = ed a0 80 ed bf bf = \"\xed\xa0\x80\xed\xbf\xbf\"                           |",
+     "5.2.2  U+D800 U+DFFF = ed a0 80 ed bf bf = \"\"                           |", "\x06"},
+    {"5.2.3  U+DB7F U+DC00 = ed ad bf ed b0 80 = \"\xed\xad\xbf\xed\xb0\x80\"                           |",
+     "5.2.3  U+DB7F U+DC00 = ed ad bf ed b0 80 = \"\"                           |", "\x06"},
+    {"5.2.4  U+DB7F U+DFFF = ed ad bf ed bf bf = \"\xed\xad\xbf\xed\xbf\xbf\"                           |",
+     "5.2.4  U+DB7F U+DFFF = ed ad bf ed bf bf = \"\"                           |", "\x06"},
+    {"5.2.5  U+DB80 U+DC00 = ed ae 80 ed b0 80 = \"\xed\xae\x80\xed\xb0\x80\"                           |",
+     "5.2.5  U+DB80 U+DC00 = ed ae 80 ed b0 80 = \"\"                           |", "\x06"},
+    {"5.2.6  U+DB80 U+DFFF = ed ae 80 ed bf bf = \"\xed\xae\x80\xed\xbf\xbf\"                           |",
+     "5.2.6  U+DB80 U+DFFF = ed ae 80 ed bf bf = \"\"                           |", "\x06"},
+    {"5.2.7  U+DBFF U+DC00 = ed af bf ed b0 80 = \"\xed\xaf\xbf\xed\xb0\x80\"                           |",
+     "5.2.7  U+DBFF U+DC00 = ed af bf ed b0 80 = \"\"                           |", "\x06"},
+    {"5.2.8  U+DBFF U+DFFF = ed af bf ed bf bf = \"\xed\xaf\xbf\xed\xbf\xbf\"                           |",
+     "5.2.8  U+DBFF U+DFFF = ed af bf ed bf bf = \"\"                           |", "\x06"},
+//    5.3 Noncharacter code positions
+//        The following "noncharacters" are "reserved for internal use" by applications, and according to older versions
+//        of the Unicode Standard "should never be interchanged". Unicode Corrigendum #9 dropped the latter restriction.
+//        Nevertheless, their presence in incoming UTF-8 data can remain a potential security risk, depending
+//        on what use is made of these codes subsequently. Examples of such internal use:
+//          - Some file APIs with 16-bit characters may use the integer value -1 = U+FFFF to signal
+//            an end-of-file (EOF) or error condition.
+//          - In some UTF-16 receivers, code point U+FFFE might trigger a byte-swap operation
+//            (to convert between UTF-16LE and UTF-16BE).
+//        With such internal use of noncharacters, it may be desirable and safer to block those code points in
+//        UTF-8 decoders, as they should never occur legitimately in incoming UTF-8 data, and could trigger
+//        unsafe behaviour in subsequent processing.
+//
+//        Particularly problematic noncharacters in 16-bit applications:
+    {"5.3.1  U+FFFE = ef bf be = \"\xef\xbf\xbe\"                                              |",
+     "5.3.1  U+FFFE = ef bf be = \"\"                                              |", "\x03"},
+    {"5.3.2  U+FFFF = ef bf bf = \"\xef\xbf\xbf\"                                              |",
+     "5.3.2  U+FFFF = ef bf bf = \"\"                                              |", "\x03"},
+    /* Fo now, we ignore those, they do not seem to be crucial anyway... */
+//    5.3.3  U+FDD0 .. U+FDEF
+//    5.3.4  U+nFFFE U+nFFFF (for n = 1..10)
+    {NULL, NULL, NULL}
+};
+
+/* BLI_utf8_invalid_strip (and indirectly, BLI_utf8_invalid_byte). */
+TEST(string, Utf8InvalidBytes)
+{
+	for (int i = 0; utf8_invalid_tests[i][0] != NULL; i++) {
+		const char *tst = utf8_invalid_tests[i][0];
+		const char *tst_stripped = utf8_invalid_tests[i][1];
+		const int num_errors = (int)utf8_invalid_tests[i][2][0];
+
+		char buff[80];
+		memcpy(buff, tst, sizeof(buff));
+
+		const int num_errors_found = BLI_utf8_invalid_strip(buff, sizeof(buff) - 1);
+
+		printf("[%02d] -> [%02d] \"%s\"  ->  \"%s\"\n", num_errors, num_errors_found, tst, buff);
+		EXPECT_EQ(num_errors, num_errors_found);
+		EXPECT_STREQ(buff, tst_stripped);
+	}
+}
diff --git a/tests/gtests/blenlib/CMakeLists.txt b/tests/gtests/blenlib/CMakeLists.txt
index 12112e7a481..a190d9cd8c5 100644
--- a/tests/gtests/blenlib/CMakeLists.txt
+++ b/tests/gtests/blenlib/CMakeLists.txt
@@ -42,6 +42,7 @@ BLENDER_TEST(BLI_math_color "bf_blenlib")
 BLENDER_TEST(BLI_math_geom "bf_blenlib;bf_intern_eigen")
 BLENDER_TEST(BLI_math_base "bf_blenlib")
 BLENDER_TEST(BLI_string "bf_blenlib")
+BLENDER_TEST(BLI_string_utf8 "bf_blenlib")
 if(WIN32)
 	BLENDER_TEST(BLI_path_util "bf_blenlib;bf_intern_utfconv;extern_wcwidth;${ZLIB_LIBRARIES}")
 else()