[Bf-blender-cvs] [d4804f00fbb] blender-v2.90-release: Fix T79575: Crash loading nested set-scenes

[Campbell Barton]

Commit: d4804f00fbbd6da311c49b2ae498a4cadf9efe92
Author: Campbell Barton
Date:   Thu Aug 6 17:12:45 2020 +1000
Branches: blender-v2.90-release
https://developer.blender.org/rBd4804f00fbbd6da311c49b2ae498a4cadf9efe92

Fix T79575: Crash loading nested set-scenes

===================================================================

M	source/blender/blenloader/intern/readfile.c

===================================================================

diff --git a/source/blender/blenloader/intern/readfile.c b/source/blender/blenloader/intern/readfile.c
index 86f1a98efa3..134e23d36e8 100644
--- a/source/blender/blenloader/intern/readfile.c
+++ b/source/blender/blenloader/intern/readfile.c
@@ -6093,6 +6093,14 @@ static bool scene_validate_setscene__liblink(Scene *sce, const int totscene)
   }
 
   for (a = 0, sce_iter = sce; sce_iter->set; sce_iter = sce_iter->set, a++) {
+    /* This runs per library (before each libraries #Main has been joined),
+     * so we can't step into other libraries since `totscene` is only for this library.
+     *
+     * Also, other libraries may not have been linked yet,
+     * while we could check #LIB_TAG_NEED_LINK the library pointer check is sufficient. */
+    if (sce->id.lib != sce_iter->id.lib) {
+      return true;
+    }
     if (sce_iter->flag & SCE_READFILE_LIBLINK_NEED_SETSCENE_CHECK) {
       return true;
     }