--- a/mercurial/bundlerepo.py	Wed Feb 21 13:05:23 2024 +0100
+++ b/mercurial/bundlerepo.py	Wed Feb 21 13:05:29 2024 +0100
@@ -269,9 +269,10 @@
     def _write(self, fp):
         raise NotImplementedError
 
-    def _updateroots(self, repo, phase, newroots, tr):
+    def _updateroots(self, repo, phase, newroots, tr, invalidate=True):
         self._phaseroots[phase] = newroots
-        self.invalidate()
+        if invalidate:
+            self.invalidate()
         self.dirty = True