diff -r 6c201f0d17b1 -r 5ce6daa67658 mercurial/ancestor.py
--- a/mercurial/ancestor.py	Fri Dec 27 02:44:00 2019 -0500
+++ b/mercurial/ancestor.py	Fri Dec 27 13:05:22 2019 -0500
@@ -331,7 +331,7 @@
 
         Result does not include the null revision."""
         self._parentrevs = pfunc
-        self._initrevs = revs = [r for r in revs if r >= stoprev]
+        self._initrevs = [r for r in revs if r >= stoprev]
         self._stoprev = stoprev
         self._inclusive = inclusive