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, 30 insertions, 35 deletions

diff --git a/source/blender/editors/space_outliner/space_outliner.cc b/source/blender/editors/space_outliner/space_outliner.cc
index 0fb17fa3f47..bb4e57a79da 100644
--- a/source/blender/editors/space_outliner/space_outliner.cc
+++ b/source/blender/editors/space_outliner/space_outliner.cc
@@ -31,7 +31,6 @@
 #include "BLI_utildefines.h"
 
 #include "BKE_context.h"
-#include "BKE_lib_remap.h"
 #include "BKE_outliner_treehash.h"
 #include "BKE_screen.h"
 
@@ -406,49 +405,45 @@ static SpaceLink *outliner_duplicate(SpaceLink *sl)
   return (SpaceLink *)space_outliner_new;
 }
 
-static void outliner_id_remap(ScrArea *area, SpaceLink *slink, const struct IDRemapper *mappings)
+static void outliner_id_remap(ScrArea *area, SpaceLink *slink, ID *old_id, ID *new_id)
 {
   SpaceOutliner *space_outliner = (SpaceOutliner *)slink;
 
-  BKE_id_remapper_apply(mappings, (ID **)&space_outliner->search_tse.id, ID_REMAP_APPLY_DEFAULT);
-
-  if (!space_outliner->treestore) {
-    return;
+  /* Some early out checks. */
+  if (!TREESTORE_ID_TYPE(old_id)) {
+    return; /* ID type is not used by outliner. */
   }
 
-  TreeStoreElem *tselem;
-  BLI_mempool_iter iter;
-  bool changed = false;
-  bool unassigned = false;
+  if (space_outliner->search_tse.id == old_id) {
+    space_outliner->search_tse.id = new_id;
+  }
 
-  BLI_mempool_iternew(space_outliner->treestore, &iter);
-  while ((tselem = static_cast<TreeStoreElem *>(BLI_mempool_iterstep(&iter)))) {
-    switch (BKE_id_remapper_apply(mappings, &tselem->id, ID_REMAP_APPLY_DEFAULT)) {
-      case ID_REMAP_RESULT_SOURCE_REMAPPED:
-        changed = true;
-        break;
-      case ID_REMAP_RESULT_SOURCE_UNASSIGNED:
+  if (space_outliner->treestore) {
+    TreeStoreElem *tselem;
+    BLI_mempool_iter iter;
+    bool changed = false;
+
+    BLI_mempool_iternew(space_outliner->treestore, &iter);
+    while ((tselem = static_cast<TreeStoreElem *>(BLI_mempool_iterstep(&iter)))) {
+      if (tselem->id == old_id) {
+        tselem->id = new_id;
         changed = true;
-        unassigned = true;
-        break;
-      case ID_REMAP_RESULT_SOURCE_UNAVAILABLE:
-      case ID_REMAP_RESULT_SOURCE_NOT_MAPPABLE:
-        break;
+      }
     }
-  }
 
-  /* Note that the Outliner may not be the active editor of the area, and hence not initialized.
-   * So runtime data might not have been created yet. */
-  if (space_outliner->runtime && space_outliner->runtime->treehash && changed) {
-    /* rebuild hash table, because it depends on ids too */
-    /* postpone a full rebuild because this can be called many times on-free */
-    space_outliner->storeflag |= SO_TREESTORE_REBUILD;
-
-    if (unassigned) {
-      /* Redraw is needed when removing data for multiple outlines show the same data.
-       * without this, the stale data won't get fully flushed when this outliner
-       * is not the active outliner the user is interacting with. See T85976. */
-      ED_area_tag_redraw(area);
+    /* Note that the Outliner may not be the active editor of the area, and hence not initialized.
+     * So runtime data might not have been created yet. */
+    if (space_outliner->runtime && space_outliner->runtime->treehash && changed) {
+      /* rebuild hash table, because it depends on ids too */
+      /* postpone a full rebuild because this can be called many times on-free */
+      space_outliner->storeflag |= SO_TREESTORE_REBUILD;
+
+      if (new_id == nullptr) {
+        /* Redraw is needed when removing data for multiple outlines show the same data.
+         * without this, the stale data won't get fully flushed when this outliner
+         * is not the active outliner the user is interacting with. See T85976. */
+        ED_area_tag_redraw(area);
+      }
     }
   }
 }