--- a/hgext3rd/evolve/stablerangecache.py	Mon Aug 27 11:27:04 2018 +0200
+++ b/hgext3rd/evolve/stablerangecache.py	Mon Aug 27 11:33:09 2018 +0200
@@ -224,6 +224,8 @@
         return con
 
     def _save(self, repo):
+        if not self._unsavedsubranges:
+            return
         try:
             return self._trysave(repo)
         except (sqlite3.OperationalError, sqlite3.IntegrityError) as exc: