Fix T84114: Existence of vertex groups slows down mesh editing

Having a vertex group in a mesh slowed down unrelated operations
such as selection.

De-duplicating custom-data arrays for layers that contain pointers
can become slow without any benefit as the content never matches.

Use full copies when storing custom-data for edit-mesh undo.

1 files changed, 12 insertions, 0 deletions

diff --git a/source/blender/blenkernel/intern/customdata.c b/source/blender/blenkernel/intern/customdata.c
index b0994fb683a..1121df0d568 100644
--- a/source/blender/blenkernel/intern/customdata.c
+++ b/source/blender/blenkernel/intern/customdata.c
@@ -4291,6 +4291,18 @@ bool CustomData_layertype_is_singleton(int type)
 }
 
 /**
+ * Has dynamically allocated members.
+ * This is useful to know if operations such as #memcmp are
+ * valid when comparing data from two layers.
+ */
+bool CustomData_layertype_is_dynamic(int type)
+{
+  const LayerTypeInfo *typeInfo = layerType_getInfo(type);
+
+  return (typeInfo->free != NULL);
+}
+
+/**
  * \return Maximum number of layers of given \a type, -1 means 'no limit'.
  */
 int CustomData_layertype_layers_max(const int type)