Fix duplicate ID's being created when appending/linking

This removes grease pencil brush creation/dat-block delete on load,
since this causes duplicate data-blocks.

Add assert to prevent this happening in the future
since the error is isn't obvious.

1 files changed, 6 insertions, 0 deletions

diff --git a/source/blender/blenkernel/BKE_main.h b/source/blender/blenkernel/BKE_main.h
index ed1f67350c3..62f50fb8ff6 100644
--- a/source/blender/blenkernel/BKE_main.h
+++ b/source/blender/blenkernel/BKE_main.h
@@ -105,6 +105,12 @@ typedef struct Main {
    */
   char use_memfile_full_barrier;
 
+  /**
+   * When linking, disallow creation of new data-blocks.
+   * Make sure we don't do this by accident, see T76738.
+   */
+  char is_locked_for_linking;
+
   BlendThumbnail *blen_thumb;
 
   struct Library *curlib;