Fix T51902: Severe problem with relocating linked libraries when using proxies.

Fix is a bit ugly, but cannot think of another solution for now, at
least this **should** not break anything else.

And now I go find myself a very remote, high and lonely mountain, climb
to its top, roar "I hate proxies!" a few times, and relax hearing the echos...

5 files changed, 14 insertions, 4 deletions

diff --git a/source/blender/blenkernel/BKE_library_query.h b/source/blender/blenkernel/BKE_library_query.h
index 6cf18e28e17..d6e7d98f371 100644
--- a/source/blender/blenkernel/BKE_library_query.h
+++ b/source/blender/blenkernel/BKE_library_query.h
@@ -83,6 +83,8 @@ enum {
 	IDWALK_NOP      = 0,
 	IDWALK_READONLY = (1 << 0),
 	IDWALK_RECURSE  = (1 << 1),  /* Also implies IDWALK_READONLY. */
+
+	IDWALK_NO_INDIRECT_PROXY_DATA_USAGE = (1 << 8),  /* Ugly special case :(((( */
 };
 
 /* Loop over all of the ID's this datablock links to. */
diff --git a/source/blender/blenkernel/BKE_library_remap.h b/source/blender/blenkernel/BKE_library_remap.h
index 53d438a0fdd..fd37fd762f4 100644
--- a/source/blender/blenkernel/BKE_library_remap.h
+++ b/source/blender/blenkernel/BKE_library_remap.h
@@ -46,6 +46,11 @@ enum {
 	/* This tells the callback func to force setting IDs using target one with a 'never NULL' pointer to NULL.
 	 * WARNING! Use with extreme care, this will leave database in broken state and can cause crashes very easily! */
 	ID_REMAP_FORCE_NEVER_NULL_USAGE = 1 << 3,
+	/* Do not consider proxy/_group pointers of local objects as indirect usages...
+	 * Our oh-so-beloved proxies again... Do not consider data used by local proxy object as indirect usage.
+	 * This is needed e.g. in reload scenario, since we have to ensure remapping of Armature data of local proxy
+	 * is also performed. Usual nightmare... */
+	ID_REMAP_NO_INDIRECT_PROXY_DATA_USAGE = 1 << 4,
 };
 
 /* Note: Requiring new_id to be non-null, this *may* not be the case ultimately, but makes things simpler for now. */
diff --git a/source/blender/blenkernel/intern/library_query.c b/source/blender/blenkernel/intern/library_query.c
index 931002e6bbc..d1f0c87183d 100644
--- a/source/blender/blenkernel/intern/library_query.c
+++ b/source/blender/blenkernel/intern/library_query.c
@@ -512,7 +512,8 @@ void BKE_library_foreach_ID_link(Main *bmain, ID *id, LibraryIDLinkCallback call
 
 				/* Object is special, proxies make things hard... */
 				const int data_cb_flag = data.cb_flag;
-				const int proxy_cb_flag = (object->proxy || object->proxy_group) ? IDWALK_CB_INDIRECT_USAGE : 0;
+				const int proxy_cb_flag = ((data.flag & IDWALK_NO_INDIRECT_PROXY_DATA_USAGE) == 0 && (object->proxy || object->proxy_group)) ?
+				                              IDWALK_CB_INDIRECT_USAGE : 0;
 
 				/* object data special case */
 				data.cb_flag |= proxy_cb_flag;
diff --git a/source/blender/blenkernel/intern/library_remap.c b/source/blender/blenkernel/intern/library_remap.c
index 01ad4fb86ce..5e5ba44f039 100644
--- a/source/blender/blenkernel/intern/library_remap.c
+++ b/source/blender/blenkernel/intern/library_remap.c
@@ -419,6 +419,7 @@ ATTR_NONNULL(1) static void libblock_remap_data(
 	IDRemap id_remap_data;
 	ListBase *lb_array[MAX_LIBARRAY];
 	int i;
+	const int foreach_id_flags = (remap_flags & ID_REMAP_NO_INDIRECT_PROXY_DATA_USAGE) != 0 ? IDWALK_NO_INDIRECT_PROXY_DATA_USAGE : IDWALK_NOP;
 
 	if (r_id_remap_data == NULL) {
 		r_id_remap_data = &id_remap_data;
@@ -439,7 +440,7 @@ ATTR_NONNULL(1) static void libblock_remap_data(
 #endif
 		r_id_remap_data->id = id;
 		libblock_remap_data_preprocess(r_id_remap_data);
-		BKE_library_foreach_ID_link(NULL, id, foreach_libblock_remap_callback, (void *)r_id_remap_data, IDWALK_NOP);
+		BKE_library_foreach_ID_link(NULL, id, foreach_libblock_remap_callback, (void *)r_id_remap_data, foreach_id_flags);
 	}
 	else {
 		i = set_listbasepointers(bmain, lb_array);
@@ -456,7 +457,7 @@ ATTR_NONNULL(1) static void libblock_remap_data(
 					r_id_remap_data->id = id_curr;
 					libblock_remap_data_preprocess(r_id_remap_data);
 					BKE_library_foreach_ID_link(
-					            NULL, id_curr, foreach_libblock_remap_callback, (void *)r_id_remap_data, IDWALK_NOP);
+					            NULL, id_curr, foreach_libblock_remap_callback, (void *)r_id_remap_data, foreach_id_flags);
 				}
 			}
 		}
diff --git a/source/blender/windowmanager/intern/wm_files_link.c b/source/blender/windowmanager/intern/wm_files_link.c
index 3b733f9558c..f19c999a4f1 100644
--- a/source/blender/windowmanager/intern/wm_files_link.c
+++ b/source/blender/windowmanager/intern/wm_files_link.c
@@ -608,7 +608,8 @@ static void lib_relocate_do(
 	}
 
 	/* Note that in reload case, we also want to replace indirect usages. */
-	const short remap_flags = ID_REMAP_SKIP_NEVER_NULL_USAGE | (do_reload ? 0 : ID_REMAP_SKIP_INDIRECT_USAGE);
+	const short remap_flags = ID_REMAP_SKIP_NEVER_NULL_USAGE | ID_REMAP_NO_INDIRECT_PROXY_DATA_USAGE |
+	                          (do_reload ? 0 : ID_REMAP_SKIP_INDIRECT_USAGE);
 	for (item_idx = 0, itemlink = lapp_data->items.list; itemlink; item_idx++, itemlink = itemlink->next) {
 		WMLinkAppendDataItem *item = itemlink->link;
 		ID *old_id = item->customdata;