Fix potential issues when loading files with missing libraries

This is a continuation of rB39f005eae8eed8b939579aff8c9a05a4f50e5e38

Now all the fields where we check for object type in RNA (like
rna_Curve_object_poll) will have a safe guard for when this isn't the
case.  For example when loading files that has missing object libraries
and all missing objects are replaced with empties (placeholders).

Reviewed By: Brecht

Differential Revision: http://developer.blender.org/D5425

2 files changed, 12 insertions, 2 deletions

diff --git a/source/blender/gpencil_modifiers/intern/MOD_gpencilarmature.c b/source/blender/gpencil_modifiers/intern/MOD_gpencilarmature.c
index 4297cbb545c..acf9b5c3642 100644
--- a/source/blender/gpencil_modifiers/intern/MOD_gpencilarmature.c
+++ b/source/blender/gpencil_modifiers/intern/MOD_gpencilarmature.c
@@ -155,7 +155,12 @@ static bool isDisabled(GpencilModifierData *md, int UNUSED(userRenderParams))
 {
   ArmatureGpencilModifierData *mmd = (ArmatureGpencilModifierData *)md;
 
-  return !mmd->object;
+  /* The object type check is only needed here in case we have a placeholder
+   * object assigned (because the library containing the armature is missing).
+   *
+   * In other cases it should be impossible to have a type missmatch.
+   */
+  return !mmd->object || mmd->object->type != OB_ARMATURE;
 }
 
 static void updateDepsgraph(GpencilModifierData *md, const ModifierUpdateDepsgraphContext *ctx)
diff --git a/source/blender/gpencil_modifiers/intern/MOD_gpencillattice.c b/source/blender/gpencil_modifiers/intern/MOD_gpencillattice.c
index d5295fc7306..765967d8346 100644
--- a/source/blender/gpencil_modifiers/intern/MOD_gpencillattice.c
+++ b/source/blender/gpencil_modifiers/intern/MOD_gpencillattice.c
@@ -169,7 +169,12 @@ static bool isDisabled(GpencilModifierData *md, int UNUSED(userRenderParams))
 {
   LatticeGpencilModifierData *mmd = (LatticeGpencilModifierData *)md;
 
-  return !mmd->object;
+  /* The object type check is only needed here in case we have a placeholder
+   * object assigned (because the library containing the lattice is missing).
+   *
+   * In other cases it should be impossible to have a type missmatch.
+   */
+  return !mmd->object || mmd->object->type != OB_LATTICE;
 }
 
 static void updateDepsgraph(GpencilModifierData *md, const ModifierUpdateDepsgraphContext *ctx)