mercurial/util.py

--- a/mercurial/util.py	Wed Nov 02 16:43:01 2022 -0400
+++ b/mercurial/util.py	Fri Nov 04 17:35:44 2022 -0400
@@ -2542,6 +2542,7 @@
         # delegated methods
         self.read = self._fp.read
         self.write = self._fp.write
+        self.writelines = self._fp.writelines
         self.seek = self._fp.seek
         self.tell = self._fp.tell
         self.fileno = self._fp.fileno