1 files changed, 12 insertions, 0 deletions
diff --git a/source/blender/editors/armature/armature_utils.c b/source/blender/editors/armature/armature_utils.c
index 5d424594229..d8777b7e0b7 100644
--- a/source/blender/editors/armature/armature_utils.c
+++ b/source/blender/editors/armature/armature_utils.c
@@ -85,6 +85,18 @@ void ED_armature_edit_validate_active(struct bArmature *arm)
   }
 }
 
+/* Update the layers_used variable after bones are moved between layer
+ * NOTE: Used to be done in drawing code in 2.7, but that won't work with
+ *       Copy-on-Write, as drawing uses evaluated copies.
+ */
+void ED_armature_edit_refresh_layer_used(bArmature *arm)
+{
+  arm->layer_used = 0;
+  for (EditBone *ebo = arm->edbo->first; ebo; ebo = ebo->next) {
+    arm->layer_used |= ebo->layer;
+  }
+}
+
 /* *************************************************************** */
 /* Bone Operations */