Bugfix [#35936] Can't create new vertex group when using Ctrl G menu

This was caused by r.57812

There were two problems here:
  1) vertex_group_vert_select_unlocked_poll()  had faulty logic which meant that
it always failed when there were no vgroups present yet - the final return
always just fell through
  2) Since the "Assign to New Groups" option was actually implemented using the
same operator as "Assign to Active Group" (just with an extra parameter set), if
the active group was locked, it was not possible to "Assign to New Group" (even
though a new group would not be locked).

5 files changed, 37 insertions, 12 deletions

diff --git a/release/scripts/startup/bl_ui/properties_data_mesh.py b/release/scripts/startup/bl_ui/properties_data_mesh.py
index 655fd4045ee..b6ad14196cd 100644
--- a/release/scripts/startup/bl_ui/properties_data_mesh.py
+++ b/release/scripts/startup/bl_ui/properties_data_mesh.py
@@ -215,7 +215,7 @@ class DATA_PT_vertex_groups(MeshButtonsPanel, Panel):
             row = layout.row()
 
             sub = row.row(align=True)
-            sub.operator("object.vertex_group_assign", text="Assign").new = False
+            sub.operator("object.vertex_group_assign", text="Assign")
             sub.operator("object.vertex_group_remove_from", text="Remove")
 
             sub = row.row(align=True)
diff --git a/release/scripts/startup/bl_ui/space_view3d.py b/release/scripts/startup/bl_ui/space_view3d.py
index 51995ba5012..0eea75e4e64 100644
--- a/release/scripts/startup/bl_ui/space_view3d.py
+++ b/release/scripts/startup/bl_ui/space_view3d.py
@@ -1312,13 +1312,13 @@ class VIEW3D_MT_vertex_group(Menu):
         layout = self.layout
 
         layout.operator_context = 'EXEC_AREA'
-        layout.operator("object.vertex_group_assign", text="Assign to New Group").new = True
+        layout.operator("object.vertex_group_assign_new")
 
         ob = context.active_object
         if ob.mode == 'EDIT' or (ob.mode == 'WEIGHT_PAINT' and ob.type == 'MESH' and ob.data.use_paint_mask_vertex):
             if ob.vertex_groups.active:
                 layout.separator()
-                layout.operator("object.vertex_group_assign", text="Assign to Active Group").new = False
+                layout.operator("object.vertex_group_assign", text="Assign to Active Group")
                 layout.operator("object.vertex_group_remove_from", text="Remove from Active Group").use_all_groups = False
                 layout.operator("object.vertex_group_remove_from", text="Remove from All").use_all_groups = True
                 layout.separator()
diff --git a/source/blender/editors/object/object_intern.h b/source/blender/editors/object/object_intern.h
index b3ce9320852..58cca9dca02 100644
--- a/source/blender/editors/object/object_intern.h
+++ b/source/blender/editors/object/object_intern.h
@@ -203,6 +203,7 @@ void CONSTRAINT_OT_followpath_path_animate(struct wmOperatorType *ot);
 void OBJECT_OT_vertex_group_add(struct wmOperatorType *ot);
 void OBJECT_OT_vertex_group_remove(struct wmOperatorType *ot);
 void OBJECT_OT_vertex_group_assign(struct wmOperatorType *ot);
+void OBJECT_OT_vertex_group_assign_new(struct wmOperatorType *ot);
 void OBJECT_OT_vertex_group_remove_from(struct wmOperatorType *ot);
 void OBJECT_OT_vertex_group_select(struct wmOperatorType *ot);
 void OBJECT_OT_vertex_group_deselect(struct wmOperatorType *ot);
diff --git a/source/blender/editors/object/object_ops.c b/source/blender/editors/object/object_ops.c
index 356bda109a4..35bfba8b78a 100644
--- a/source/blender/editors/object/object_ops.c
+++ b/source/blender/editors/object/object_ops.c
@@ -175,6 +175,7 @@ void ED_operatortypes_object(void)
 	WM_operatortype_append(OBJECT_OT_vertex_group_add);
 	WM_operatortype_append(OBJECT_OT_vertex_group_remove);
 	WM_operatortype_append(OBJECT_OT_vertex_group_assign);
+	WM_operatortype_append(OBJECT_OT_vertex_group_assign_new);
 	WM_operatortype_append(OBJECT_OT_vertex_group_remove_from);
 	WM_operatortype_append(OBJECT_OT_vertex_group_select);
 	WM_operatortype_append(OBJECT_OT_vertex_group_deselect);
diff --git a/source/blender/editors/object/object_vgroup.c b/source/blender/editors/object/object_vgroup.c
index e1a18158c2d..c4fb3188528 100644
--- a/source/blender/editors/object/object_vgroup.c
+++ b/source/blender/editors/object/object_vgroup.c
@@ -2993,7 +2993,7 @@ static int vertex_group_vert_select_unlocked_poll(bContext *C)
 			return !(dg->flag & DG_LOCK_WEIGHT);
 		}
 	}
-	return 0;
+	return 1;
 }
 
 static int vertex_group_vert_select_mesh_poll(bContext *C)
@@ -3080,10 +3080,7 @@ static int vertex_group_assign_exec(bContext *C, wmOperator *op)
 {
 	ToolSettings *ts = CTX_data_tool_settings(C);
 	Object *ob = ED_object_context(C);
-
-	if (RNA_boolean_get(op->ptr, "new"))
-		ED_vgroup_add(ob);
-
+	
 	vgroup_assign_verts(ob, ts->vgroup_weight);
 	DAG_id_tag_update(&ob->id, OB_RECALC_DATA);
 	WM_event_add_notifier(C, NC_GEOM | ND_DATA, ob->data);
@@ -3094,9 +3091,9 @@ static int vertex_group_assign_exec(bContext *C, wmOperator *op)
 void OBJECT_OT_vertex_group_assign(wmOperatorType *ot)
 {
 	/* identifiers */
-	ot->name = "Assign Vertex Group";
+	ot->name = "Assign to Vertex Group";
 	ot->idname = "OBJECT_OT_vertex_group_assign";
-	ot->description = "Assign the selected vertices to the active (or a new) vertex group";
+	ot->description = "Assign the selected vertices to the active vertex group";
 	
 	/* api callbacks */
 	ot->poll = vertex_group_vert_select_unlocked_poll;
@@ -3107,9 +3104,35 @@ void OBJECT_OT_vertex_group_assign(wmOperatorType *ot)
 	 * isn't stored in local edit mode stack and toggling "new" property will
 	 * lead to creating plenty of new vertex groups (see [#29527], sergey) */
 	ot->flag = /*OPTYPE_REGISTER|*/ OPTYPE_UNDO;
+}
 
-	/* properties */
-	RNA_def_boolean(ot->srna, "new", 0, "New", "Assign vertex to new vertex group");
+/* NOTE: just a wrapper around vertex_group_assign_exec(), except we add these to a new group */
+static int vertex_group_assign_new_exec(bContext *C, wmOperator *op)
+{
+	/* create new group... */
+	Object *ob = ED_object_context(C);
+	ED_vgroup_add(ob);
+	
+	/* assign selection to new group */
+	return vertex_group_assign_exec(C, op);
+}
+
+void OBJECT_OT_vertex_group_assign_new(wmOperatorType *ot)
+{
+	/* identifiers */
+	ot->name = "Assign to New Group";
+	ot->idname = "OBJECT_OT_vertex_group_assign_new";
+	ot->description = "Assign the selected vertices to a new vertex group";
+	
+	/* api callbacks */
+	ot->poll = vertex_group_vert_select_poll;
+	ot->exec = vertex_group_assign_new_exec;
+	
+	/* flags */
+	/* redo operator will fail in this case because vertex group assignment
+	 * isn't stored in local edit mode stack and toggling "new" property will
+	 * lead to creating plenty of new vertex groups (see [#29527], sergey) */
+	ot->flag = /*OPTYPE_REGISTER|*/ OPTYPE_UNDO;
 }
 
 static int vertex_group_remove_from_exec(bContext *C, wmOperator *op)