--- a/mercurial/changelog.py	Tue Jul 16 21:15:35 2019 -0700
+++ b/mercurial/changelog.py	Tue Jul 16 21:15:39 2019 -0700
@@ -637,6 +637,9 @@
         if extra is None and any(x is not None for x in extrasentries):
             extra = {}
         sortedfiles = sorted(files)
+        if extra is not None:
+            for name in ('p1copies', 'p2copies', 'filesadded', 'filesremoved'):
+                extra.pop(name, None)
         if p1copies is not None:
             extra['p1copies'] = encodecopies(sortedfiles, p1copies)
         if p2copies is not None: