Fix T58652: Crash editing shape keys weirdness with instances

This is a second attempt to get the crash fixed. The original fix
worked, but it was reverted by d3e0d7f0825.

Now the logic goes as:

- All pointers which we can not have shared (the ones which are
  owned by the runtime) are cleared.
- The rest of runtime stays untouched.

This seems to be enough to keep particles happy.

1 files changed, 1 insertions, 0 deletions

diff --git a/source/blender/blenkernel/BKE_mesh_runtime.h b/source/blender/blenkernel/BKE_mesh_runtime.h
index 8f9de85a302..49e452edc36 100644
--- a/source/blender/blenkernel/BKE_mesh_runtime.h
+++ b/source/blender/blenkernel/BKE_mesh_runtime.h
@@ -54,6 +54,7 @@ struct DerivedMesh;
 #endif
 
 void BKE_mesh_runtime_reset(struct Mesh *mesh);
+void BKE_mesh_runtime_reset_on_copy(struct Mesh *mesh);
 int BKE_mesh_runtime_looptri_len(const struct Mesh *mesh);
 void BKE_mesh_runtime_looptri_recalc(struct Mesh *mesh);
 const struct MLoopTri *BKE_mesh_runtime_looptri_ensure(struct Mesh *mesh);