1 files changed, 90 insertions, 27 deletions

diff --git a/source/blender/blenkernel/intern/library_override.c b/source/blender/blenkernel/intern/library_override.c
index ce368575492..4f10a5bca6b 100644
--- a/source/blender/blenkernel/intern/library_override.c
+++ b/source/blender/blenkernel/intern/library_override.c
@@ -57,7 +57,7 @@ static void bke_override_property_operation_clear(IDOverrideLibraryPropertyOpera
 
 /* Temp, for until library override is ready and tested enough to go 'public',
  * we hide it by default in UI and such. */
-static bool _override_library_enabled = false;
+static bool _override_library_enabled = true;
 
 void BKE_override_library_enable(const bool do_enable)
 {
@@ -111,11 +111,11 @@ void BKE_override_library_copy(ID *dst_id, const ID *src_id)
 
   if (dst_id->override_library != NULL) {
     if (src_id->override_library == NULL) {
-      BKE_override_library_free(&dst_id->override_library);
+      BKE_override_library_free(&dst_id->override_library, true);
       return;
     }
     else {
-      BKE_override_library_clear(dst_id->override_library);
+      BKE_override_library_clear(dst_id->override_library, true);
     }
   }
   else if (src_id->override_library == NULL) {
@@ -144,7 +144,7 @@ void BKE_override_library_copy(ID *dst_id, const ID *src_id)
 }
 
 /** Clear any overriding data from given \a override. */
-void BKE_override_library_clear(IDOverrideLibrary *override)
+void BKE_override_library_clear(IDOverrideLibrary *override, const bool do_id_user)
 {
   BLI_assert(override != NULL);
 
@@ -153,16 +153,18 @@ void BKE_override_library_clear(IDOverrideLibrary *override)
   }
   BLI_freelistN(&override->properties);
 
-  id_us_min(override->reference);
-  /* override->storage should never be refcounted... */
+  if (do_id_user) {
+    id_us_min(override->reference);
+    /* override->storage should never be refcounted... */
+  }
 }
 
 /** Free given \a override. */
-void BKE_override_library_free(struct IDOverrideLibrary **override)
+void BKE_override_library_free(struct IDOverrideLibrary **override, const bool do_id_user)
 {
   BLI_assert(*override != NULL);
 
-  BKE_override_library_clear(*override);
+  BKE_override_library_clear(*override, do_id_user);
   MEM_freeN(*override);
   *override = NULL;
 }
@@ -183,19 +185,28 @@ static ID *override_library_create_from(Main *bmain, ID *reference_id)
 }
 
 /** Create an overridden local copy of linked reference. */
-ID *BKE_override_library_create_from_id(Main *bmain, ID *reference_id)
+ID *BKE_override_library_create_from_id(Main *bmain, ID *reference_id, const bool do_tagged_remap)
 {
   BLI_assert(reference_id != NULL);
   BLI_assert(reference_id->lib != NULL);
 
   ID *local_id = override_library_create_from(bmain, reference_id);
 
-  /* Remapping, we obviously only want to affect local data
-   * (and not our own reference pointer to overridden ID). */
-  BKE_libblock_remap(bmain,
-                     reference_id,
-                     local_id,
-                     ID_REMAP_SKIP_INDIRECT_USAGE | ID_REMAP_SKIP_OVERRIDE_LIBRARY);
+  if (do_tagged_remap) {
+    ID *other_id;
+    FOREACH_MAIN_ID_BEGIN (bmain, other_id) {
+      if ((other_id->tag & LIB_TAG_DOIT) != 0 && other_id->lib == NULL) {
+        /* Note that using ID_REMAP_SKIP_INDIRECT_USAGE below is superfluous, as we only remap
+         * local IDs usages anyway... */
+        BKE_libblock_relink_ex(bmain,
+                               other_id,
+                               reference_id,
+                               local_id,
+                               ID_REMAP_SKIP_INDIRECT_USAGE | ID_REMAP_SKIP_OVERRIDE_LIBRARY);
+      }
+    }
+    FOREACH_MAIN_ID_END;
+  }
 
   return local_id;
 }
@@ -205,6 +216,11 @@ ID *BKE_override_library_create_from_id(Main *bmain, ID *reference_id)
  * \note Set id->newid of overridden libs with newly created overrides,
  * caller is responsible to clean those pointers before/after usage as needed.
  *
+ * \note By default, it will only remap newly created local overriding data-blocks between
+ * themselves, to avoid 'enforcing' those overrides into all other usages of the linked data in
+ * main. You can add more local IDs to be remapped to use new overriding ones by setting their
+ * LIB_TAG_DOIT tag.
+ *
  * \return \a true on success, \a false otherwise.
  */
 bool BKE_override_library_create_from_tag(Main *bmain)
@@ -212,26 +228,59 @@ bool BKE_override_library_create_from_tag(Main *bmain)
   ID *reference_id;
   bool ret = true;
 
+  ListBase todo_ids = {NULL};
+  LinkData *todo_id_iter;
+
+  /* Get all IDs we want to override. */
   FOREACH_MAIN_ID_BEGIN (bmain, reference_id) {
     if ((reference_id->tag & LIB_TAG_DOIT) != 0 && reference_id->lib != NULL) {
-      if ((reference_id->newid = override_library_create_from(bmain, reference_id)) == NULL) {
-        ret = false;
-      }
+      todo_id_iter = MEM_callocN(sizeof(*todo_id_iter), __func__);
+      todo_id_iter->data = reference_id;
+      BLI_addtail(&todo_ids, todo_id_iter);
     }
   }
   FOREACH_MAIN_ID_END;
 
-  FOREACH_MAIN_ID_BEGIN (bmain, reference_id) {
-    if ((reference_id->tag & LIB_TAG_DOIT) != 0 && reference_id->lib != NULL &&
-        reference_id->newid != NULL) {
-      ID *local_id = reference_id->newid;
-      BKE_libblock_remap(bmain,
-                         reference_id,
-                         local_id,
-                         ID_REMAP_SKIP_INDIRECT_USAGE | ID_REMAP_SKIP_OVERRIDE_LIBRARY);
+  /* Override the IDs. */
+  for (todo_id_iter = todo_ids.first; todo_id_iter != NULL; todo_id_iter = todo_id_iter->next) {
+    reference_id = todo_id_iter->data;
+    if ((reference_id->newid = override_library_create_from(bmain, reference_id)) == NULL) {
+      ret = false;
+    }
+    else {
+      /* We also tag the new IDs so that in next step we can remap their pointers too. */
+      reference_id->newid->tag |= LIB_TAG_DOIT;
     }
   }
-  FOREACH_MAIN_ID_END;
+
+  /* Only remap new local ID's pointers, we don't want to force our new overrides onto our whole
+   * existing linked IDs usages. */
+  for (todo_id_iter = todo_ids.first; todo_id_iter != NULL; todo_id_iter = todo_id_iter->next) {
+    ID *other_id;
+    reference_id = todo_id_iter->data;
+
+    if (reference_id->newid == NULL) {
+      continue;
+    }
+
+    /* Still checking the whole Main, that way we can tag other local IDs as needing to be remapped
+     * to use newly created overriding IDs, if needed. */
+    FOREACH_MAIN_ID_BEGIN (bmain, other_id) {
+      if ((other_id->tag & LIB_TAG_DOIT) != 0 && other_id->lib == NULL) {
+        ID *local_id = reference_id->newid;
+        /* Note that using ID_REMAP_SKIP_INDIRECT_USAGE below is superfluous, as we only remap
+         * local IDs usages anyway... */
+        BKE_libblock_relink_ex(bmain,
+                               other_id,
+                               reference_id,
+                               local_id,
+                               ID_REMAP_SKIP_INDIRECT_USAGE | ID_REMAP_SKIP_OVERRIDE_LIBRARY);
+      }
+    }
+    FOREACH_MAIN_ID_END;
+  }
+
+  BLI_freelistN(&todo_ids);
 
   return ret;
 }
@@ -592,6 +641,13 @@ bool BKE_override_library_operations_create(Main *bmain, ID *local, const bool f
   bool ret = false;
 
   if (!is_template && (force_auto || local->override_library->flag & OVERRIDE_LIBRARY_AUTO)) {
+    /* Do not attempt to generate overriding rules from an empty place-holder generated by link
+     * code when it cannot find to actual library/ID. Much better to keep the local datablock as
+     * is in the file in that case, until broken lib is fixed. */
+    if (ID_MISSING(local->override_library->reference)) {
+      return ret;
+    }
+
     PointerRNA rnaptr_local, rnaptr_reference;
     RNA_id_pointer_create(local, &rnaptr_local);
     RNA_id_pointer_create(local->override_library->reference, &rnaptr_reference);
@@ -644,6 +700,13 @@ void BKE_override_library_update(Main *bmain, ID *local)
     return;
   }
 
+  /* Do not attempt to apply overriding rules over an empty place-holder generated by link code
+   * when it cannot find to actual library/ID. Much better to keep the local datablock as loaded
+   * from the file in that case, until broken lib is fixed. */
+  if (ID_MISSING(local->override_library->reference)) {
+    return;
+  }
+
   /* Recursively do 'ancestors' overrides first, if any. */
   if (local->override_library->reference->override_library &&
       (local->override_library->reference->tag & LIB_TAG_OVERRIDE_LIBRARY_REFOK) == 0) {