Fix T72593 Blender crashes when modifier change the material count

Instead of changing the modifiers behavior, we make sure to always use
the data->totcol instead of the ob->totcol. Also we centralize getting
this number to avoid future issues.

Fix T72593 Blender crashes when separating mesh
Fix T72017 Crash on set visibility change

1 files changed, 6 insertions, 1 deletions

diff --git a/source/blender/draw/intern/draw_cache_impl_curve.c b/source/blender/draw/intern/draw_cache_impl_curve.c
index ab800e42cc0..05ec9bda642 100644
--- a/source/blender/draw/intern/draw_cache_impl_curve.c
+++ b/source/blender/draw/intern/draw_cache_impl_curve.c
@@ -414,7 +414,7 @@ static bool curve_batch_cache_valid(Curve *cu)
     return false;
   }
 
-  if (cache->mat_len != max_ii(1, cu->totcol)) {
+  if (cache->mat_len != DRW_curve_material_count_get(cu)) {
     return false;
   }
 
@@ -914,6 +914,11 @@ GPUBatch *DRW_curve_batch_cache_get_edge_detection(Curve *cu, bool *r_is_manifol
   return DRW_batch_request(&cache->batch.edge_detection);
 }
 
+int DRW_curve_material_count_get(Curve *cu)
+{
+  return max_ii(1, cu->totcol);
+}
+
 /** \} */
 
 /* -------------------------------------------------------------------- */