[Bf-blender-cvs] [72fec0f7c58] blender-v2.93-release: Fix T87055: Crash applying modifier on mesh with multires data

[Campbell Barton]

Commit: 72fec0f7c5865a30aa348bc6e76271ba9a5a606e
Author: Campbell Barton
Date:   Tue Apr 20 15:10:43 2021 +1000
Branches: blender-v2.93-release
https://developer.blender.org/rB72fec0f7c5865a30aa348bc6e76271ba9a5a606e

Fix T87055: Crash applying modifier on mesh with multires data

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

M	source/blender/blenkernel/intern/mesh_convert.c

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

diff --git a/source/blender/blenkernel/intern/mesh_convert.c b/source/blender/blenkernel/intern/mesh_convert.c
index 385fd473e63..a4122dcca41 100644
--- a/source/blender/blenkernel/intern/mesh_convert.c
+++ b/source/blender/blenkernel/intern/mesh_convert.c
@@ -1634,6 +1634,10 @@ void BKE_mesh_nomain_to_mesh(Mesh *mesh_src,
     if (totloop == mesh_dst->totloop) {
       MDisps *mdisps = CustomData_get_layer(&mesh_dst->ldata, CD_MDISPS);
       CustomData_add_layer(&tmp.ldata, CD_MDISPS, alloctype, mdisps, totloop);
+      if (alloctype == CD_ASSIGN) {
+        /* Assign NULL to prevent double-free. */
+        CustomData_set_layer(&mesh_dst->ldata, CD_MDISPS, NULL);
+      }
     }
   }