Revert "Fix T77774: New undo code broken by 'make local' behavior."

This reverts commit 554ed613ae5f26b205f65ed950ae50baf9f009b5.

2 files changed, 2 insertions, 38 deletions

diff --git a/source/blender/blenkernel/intern/lib_id.c b/source/blender/blenkernel/intern/lib_id.c
index 7ae6a6aab8c..b4513fc2805 100644
--- a/source/blender/blenkernel/intern/lib_id.c
+++ b/source/blender/blenkernel/intern/lib_id.c
@@ -177,16 +177,6 @@ static void lib_id_library_local_paths(Main *bmain, Library *lib, ID *id)
                         (void *)bpath_user_data);
 }
 
-static int lib_id_clear_library_data_users_update_cb(LibraryIDLinkCallbackData *cb_data)
-{
-  ID *id = cb_data->user_data;
-  if (*cb_data->id_pointer == id) {
-    DEG_id_tag_update_ex(cb_data->bmain, cb_data->id_owner, ID_RECALC_TAG_FOR_UNDO);
-    return IDWALK_RET_STOP_ITER;
-  }
-  return IDWALK_RET_NOP;
-}
-
 /**
  * Pull an ID out of a library (make it local). Only call this for IDs that
  * don't have other library users.
@@ -209,21 +199,6 @@ static void lib_id_clear_library_data_ex(Main *bmain, ID *id)
     }
   }
 
-  /* Conceptually, an ID made local is not the same as the linked one anymore. Reflect that by
-   * regenerating its session UUID. */
-  BKE_lib_libblock_session_uuid_renew(id);
-
-  /* We need to tag this IDs and all of its users, conceptually new local ID and original linked
-   * ones are two completely different data-blocks that were virtually remaped, even though in
-   * reality they remain the same data. For undo this info is critical now. */
-  DEG_id_tag_update_ex(bmain, id, ID_RECALC_COPY_ON_WRITE);
-  ID *id_iter;
-  FOREACH_MAIN_ID_BEGIN (bmain, id_iter) {
-    BKE_library_foreach_ID_link(
-        bmain, id_iter, lib_id_clear_library_data_users_update_cb, id, IDWALK_READONLY);
-  }
-  FOREACH_MAIN_ID_END;
-
   /* Internal shape key blocks inside data-blocks also stores id->lib,
    * make sure this stays in sync (note that we do not need any explicit handling for real EMBEDDED
    * IDs here, this is down automatically in `lib_id_expand_local_cb()`. */
@@ -1126,10 +1101,8 @@ void BKE_lib_libblock_session_uuid_ensure(ID *id)
 /**
  * Re-generate a new session-wise uuid for the given \a id.
  *
- * \warning This has a few very specific use-cases, no other usage is expected currently:
- *   - To handle UI-related data-blocks that are kept across new file reading, when we do keep
- * existing UI.
- *   - For IDs that are made local without needing any copying.
+ * \warning This has a very specific use-case (to handle UI-related data-blocks that are kept
+ * across new file reading, when we do keep existing UI). No other usage is expected currently.
  */
 void BKE_lib_libblock_session_uuid_renew(ID *id)
 {
diff --git a/source/blender/makesdna/DNA_ID.h b/source/blender/makesdna/DNA_ID.h
index 0cf45fa4bcc..7ce84e0092c 100644
--- a/source/blender/makesdna/DNA_ID.h
+++ b/source/blender/makesdna/DNA_ID.h
@@ -680,15 +680,6 @@ typedef enum IDRecalcFlag {
    * input file or for color space changes. */
   ID_RECALC_SOURCE = (1 << 23),
 
-  /* Virtual recalc tag/marker required for undo in some cases, where actual data does not change
-   * and hence do not require an update, but conceptually we are dealing with something new.
-   *
-   * Current known case: linked IDs made local without requiring any copy. While their users do not
-   * require any update, they have actually been 'virtually' remapped from the linked ID to the
-   * local one.
-   */
-  ID_RECALC_TAG_FOR_UNDO = (1 << 24),
-
   /***************************************************************************
    * Pseudonyms, to have more semantic meaning in the actual code without
    * using too much low-level and implementation specific tags. */