Propagate unchanged resource state

simonrw · simonrw · commit 4ad07df1ab72 · 2025-05-08T16:14:18.000+01:00
diff --git a/localstack-core/localstack/services/cloudformation/engine/v2/change_set_model_executor.py b/localstack-core/localstack/services/cloudformation/engine/v2/change_set_model_executor.py
@@ -121,7 +121,9 @@ def _execute_on_resource_change(
         self, name: str, before: Optional[PreprocResource], after: Optional[PreprocResource]
     ) -> None:
         if before == after:
-            # unchanged: nothing to do.
+            # unchanged: nothing to do but propagate the previous state to the new state.
+            if before_properties := self._before_resolved_resources.get(name):
+                self.resources[name] = before_properties.copy()
             return
         # TODO: this logic is a POC and should be revised.
         if before is not None and after is not None:
