[Bf-blender-cvs] [5cf04fe2bae] master: Fix (unreported) copying liboverride of mesh breaks overrides of shape keys.

[Bastien Montagne]

Commit: 5cf04fe2bae0f4031245794287f1b4903436cc07
Author: Bastien Montagne
Date:   Fri Jan 15 17:44:35 2021 +0100
Branches: master
https://developer.blender.org/rB5cf04fe2bae0f4031245794287f1b4903436cc07

Fix (unreported) copying liboverride of mesh breaks overrides of shape keys.

Our beloved shapekeys are 'virtual' overrides, they need special
snowflake treatment here as well.

They do not have any override data, from override perspective they are
considered as mere sub-data from their owning ID (mesh, lattice, etc.).
Therefore, we should not copy override data from them, but instead
properly flag those new IDs as `LIB_EMBEDDED_DATA_LIB_OVERRIDE`.

Found while investigating T84373.

===================================================================

M	source/blender/blenkernel/intern/lib_id.c

===================================================================

diff --git a/source/blender/blenkernel/intern/lib_id.c b/source/blender/blenkernel/intern/lib_id.c
index 0cba26dd3d2..13f76b46570 100644
--- a/source/blender/blenkernel/intern/lib_id.c
+++ b/source/blender/blenkernel/intern/lib_id.c
@@ -1261,10 +1261,17 @@ void BKE_libblock_copy_ex(Main *bmain, const ID *id, ID **r_newid, const int ori
 
   /* We may need our own flag to control that at some point, but for now 'no main' one should be
    * good enough. */
-  if ((orig_flag & LIB_ID_CREATE_NO_MAIN) == 0 && ID_IS_OVERRIDE_LIBRARY(id)) {
-    /* We do not want to copy existing override rules here, as they would break the proper
-     * remapping between IDs. Proper overrides rules will be re-generated anyway. */
-    BKE_lib_override_library_copy(new_id, id, false);
+  if ((orig_flag & LIB_ID_CREATE_NO_MAIN) == 0) {
+    if (ID_IS_OVERRIDE_LIBRARY_REAL(id)) {
+      /* We do not want to copy existing override rules here, as they would break the proper
+       * remapping between IDs. Proper overrides rules will be re-generated anyway. */
+      BKE_lib_override_library_copy(new_id, id, false);
+    }
+    else if (ID_IS_OVERRIDE_LIBRARY_VIRTUAL(id)) {
+      /* Just ensure virtual overrides do get properly tagged, there is not actual override data to
+       * copy here. */
+      new_id->flag |= LIB_EMBEDDED_DATA_LIB_OVERRIDE;
+    }
   }
 
   if (id_can_have_animdata(new_id)) {