[Bf-blender-cvs] [5aaf48c052c] undo-experiments-swap-reread-datablocks: Merge branch 'undo-experiments' into undo-experiments-swap-reread-datablocks

[Bastien Montagne]

Commit: 5aaf48c052c9414bb3eaaeb6ce8e81ef989432b0
Author: Bastien Montagne
Date:   Wed Jan 29 11:05:52 2020 +0100
Branches: undo-experiments-swap-reread-datablocks
https://developer.blender.org/rB5aaf48c052c9414bb3eaaeb6ce8e81ef989432b0

Merge branch 'undo-experiments' into undo-experiments-swap-reread-datablocks

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



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

diff --cc source/blender/blenloader/intern/readfile.c
index a6d5d55b2ed,cd65ceb889d..308c63bb0c2
--- a/source/blender/blenloader/intern/readfile.c
+++ b/source/blender/blenloader/intern/readfile.c
@@@ -9712,31 -9703,15 +9715,38 @@@ static BHead *read_libblock(FileData *f
    oldnewmap_clear(fd->datamap);
  
    if (wrong_id) {
+     /* XXX This is probably working OK currently given the very limited scope of that flag.
+      * However, it is absolutely **not** handled correctly: it is freeing an ID pointer that has
+      * been added to the fd->libmap mapping, which in theory could lead to nice crashes...
+      * This should be properly solved at some point. */
      BKE_id_free(main, id);
+     if (r_id != NULL) {
+       *r_id = NULL;
+     }
    }
 +  else if (do_id_swap) {
 +    /* During memfile undo, if an ID changed and we cannot directly re-use existing one from old
 +     * bmain, we do a full read of the new id from the memfile, and then fully swap its content
 +     * with the old id. This allows us to keep the same pointer even for modified data, which helps
 +     * reducing further detected changes by the depsgraph (since unchanged IDs remain fully
 +     * unchanged, even if they are using/pointing to a changed one). */
 +
 +    BLI_assert((fd->skip_flags & BLO_READ_SKIP_UNDO_OLD_MAIN) == 0);
 +
 +    Main *old_bmain = fd->old_mainlist->first;
 +    BLI_assert(old_bmain == BKE_main_idmap_main_get(fd->old_idmap));
 +    BLI_assert(id_old != NULL);
 +
 +    ListBase *old_lb = which_libbase(old_bmain, idcode);
 +    ListBase *new_lb = which_libbase(main, idcode);
 +    BLI_remlink(old_lb, id_old);
 +    BLI_remlink(new_lb, id);
 +
 +    BKE_id_full_swap(NULL, id, id_old);
 +
 +    BLI_addtail(new_lb, id_old);
 +    BLI_addtail(old_lb, id);
 +  }
  
    return (bhead);
  }