Fix sculpt/paint missing undo-step limiting

2 files changed, 4 insertions, 2 deletions

diff --git a/source/blender/blenkernel/BKE_undo_system.h b/source/blender/blenkernel/BKE_undo_system.h
index 4870b19fe1d..f462a7fab71 100644
--- a/source/blender/blenkernel/BKE_undo_system.h
+++ b/source/blender/blenkernel/BKE_undo_system.h
@@ -152,6 +152,8 @@ void BKE_undosys_stack_init_from_context(UndoStack *ustack, struct bContext *C);
 UndoStep *BKE_undosys_stack_active_with_type(UndoStack *ustack, const UndoType *ut);
 UndoStep *BKE_undosys_stack_init_or_active_with_type(UndoStack *ustack, const UndoType *ut);
 void BKE_undosys_stack_limit_steps_and_memory(UndoStack *ustack, int steps, size_t memory_limit);
+#define BKE_undosys_stack_limit_steps_and_memory_defaults(ustack) \
+  BKE_undosys_stack_limit_steps_and_memory(ustack, U.undosteps, (size_t)U.undomemory * 1024 * 1024)
 
 /* Only some UndoType's require init. */
 UndoStep *BKE_undosys_step_push_init_with_type(UndoStack *ustack,
diff --git a/source/blender/blenkernel/intern/undo_system.c b/source/blender/blenkernel/intern/undo_system.c
index 33a457386e8..e155dedeef0 100644
--- a/source/blender/blenkernel/intern/undo_system.c
+++ b/source/blender/blenkernel/intern/undo_system.c
@@ -399,7 +399,7 @@ UndoStep *BKE_undosys_stack_init_or_active_with_type(UndoStack *ustack, const Un
 void BKE_undosys_stack_limit_steps_and_memory(UndoStack *ustack, int steps, size_t memory_limit)
 {
   UNDO_NESTED_ASSERT(false);
-  if (!(steps || memory_limit)) {
+  if ((steps == -1) && (memory_limit != 0)) {
     return;
   }
 
@@ -416,7 +416,7 @@ void BKE_undosys_stack_limit_steps_and_memory(UndoStack *ustack, int steps, size
         break;
       }
     }
-    if (steps) {
+    if (steps != -1) {
       if (us_count == steps) {
         break;
       }