[Bf-blender-cvs] [69a7015e126] blender-v2.92-release: Fix (unreported) copying liboverride of mesh breaks overrides of shape keys.

[Bastien Montagne]

Commit: 69a7015e126dbb7cb50ce81d53174be4640fd26a
Author: Bastien Montagne
Date:   Fri Jan 15 17:44:35 2021 +0100
Branches: blender-v2.92-release
https://developer.blender.org/rB69a7015e126dbb7cb50ce81d53174be4640fd26a

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)) {