Fix: Assert in legacy mesh conversion

When setting the old face set custom data type, do it in the
"layers to write" vector instead of the mesh's poly custom
data layers, which weren't "prepared" yet. Otherwise this
could make the mesh's custom data typemap invalid.

1 files changed, 3 insertions, 2 deletions

diff --git a/source/blender/blenkernel/intern/mesh_legacy_convert.cc b/source/blender/blenkernel/intern/mesh_legacy_convert.cc
index b68117b7eb2..df3057d9592 100644
--- a/source/blender/blenkernel/intern/mesh_legacy_convert.cc
+++ b/source/blender/blenkernel/intern/mesh_legacy_convert.cc
@@ -922,10 +922,11 @@ void BKE_mesh_add_mface_layers(CustomData *fdata, CustomData *ldata, int total)
 /** \name Face Set Conversion
  * \{ */
 
-void BKE_mesh_legacy_face_set_from_generic(Mesh *mesh)
+void BKE_mesh_legacy_face_set_from_generic(Mesh *mesh,
+                                           blender::MutableSpan<CustomDataLayer> poly_layers)
 {
   using namespace blender;
-  for (CustomDataLayer &layer : MutableSpan(mesh->pdata.layers, mesh->pdata.totlayer)) {
+  for (CustomDataLayer &layer : poly_layers) {
     if (StringRef(layer.name) == ".sculpt_face_set") {
       layer.type = CD_SCULPT_FACE_SETS;
     }