Revert "Performance: Remap multiple items in UI"

This reverts commit 948211679f2a0681421160be0d3b90f507bc0be7.
This commit introduced some regressions in the test suite.
As this change is a core part of blender Bastien and I decided to revert
it as the solution isn't clear and needs more investigation.

The following tests FAILED:
	 62 - blendfile_liblink (SEGFAULT)
	 63 - blendfile_library_overrides (SEGFAULT)

It fails in (id_us_ensure_real)

1 files changed, 14 insertions, 25 deletions

diff --git a/source/blender/blenkernel/intern/lib_id_delete.c b/source/blender/blenkernel/intern/lib_id_delete.c
index f4dd67cac28..6d2e89187f7 100644
--- a/source/blender/blenkernel/intern/lib_id_delete.c
+++ b/source/blender/blenkernel/intern/lib_id_delete.c
@@ -154,10 +154,7 @@ void BKE_id_free_ex(Main *bmain, void *idv, int flag, const bool use_flag_from_i
     }
 
     if (remap_editor_id_reference_cb) {
-      struct IDRemapper *remapper = BKE_id_remapper_create();
-      BKE_id_remapper_add(remapper, id, NULL);
-      remap_editor_id_reference_cb(remapper);
-      BKE_id_remapper_free(remapper);
+      remap_editor_id_reference_cb(id, NULL);
     }
   }
 
@@ -295,40 +292,32 @@ static size_t id_delete(Main *bmain, const bool do_tagged_deletion)
      * Note that we go forward here, since we want to check dependencies before users
      * (e.g. meshes before objects).
      * Avoids to have to loop twice. */
-    struct IDRemapper *remapper = BKE_id_remapper_create();
     for (i = 0; i < base_count; i++) {
       ListBase *lb = lbarray[i];
       ID *id, *id_next;
-      BKE_id_remapper_clear(remapper);
 
       for (id = lb->first; id; id = id_next) {
         id_next = id->next;
         /* NOTE: in case we delete a library, we also delete all its datablocks! */
         if ((id->tag & tag) || (id->lib != NULL && (id->lib->id.tag & tag))) {
           id->tag |= tag;
-          BKE_id_remapper_add(remapper, id, NULL);
-        }
-      }
 
-      if (BKE_id_remapper_is_empty(remapper)) {
-        continue;
+          /* Will tag 'never NULL' users of this ID too.
+           * Note that we cannot use BKE_libblock_unlink() here, since it would ignore indirect
+           * (and proxy!) links, this can lead to nasty crashing here in second,
+           * actual deleting loop.
+           * Also, this will also flag users of deleted data that cannot be unlinked
+           * (object using deleted obdata, etc.), so that they also get deleted. */
+          BKE_libblock_remap_locked(bmain,
+                                    id,
+                                    NULL,
+                                    (ID_REMAP_FLAG_NEVER_NULL_USAGE |
+                                     ID_REMAP_FORCE_NEVER_NULL_USAGE |
+                                     ID_REMAP_FORCE_INTERNAL_RUNTIME_POINTERS));
+        }
       }
-
-      /* Will tag 'never NULL' users of this ID too.
-       * Note that we cannot use BKE_libblock_unlink() here, since it would ignore indirect
-       * (and proxy!) links, this can lead to nasty crashing here in second,
-       * actual deleting loop.
-       * Also, this will also flag users of deleted data that cannot be unlinked
-       * (object using deleted obdata, etc.), so that they also get deleted. */
-      BKE_libblock_remap_multiple_locked(bmain,
-                                         remapper,
-                                         (ID_REMAP_FLAG_NEVER_NULL_USAGE |
-                                          ID_REMAP_FORCE_NEVER_NULL_USAGE |
-                                          ID_REMAP_FORCE_INTERNAL_RUNTIME_POINTERS));
     }
-    BKE_id_remapper_free(remapper);
   }
-
   BKE_main_unlock(bmain);
 
   /* In usual reversed order, such that all usage of a given ID, even 'never NULL' ones,