diff --git a/hgext/narrow/narrowrevlog.py b/hgext/narrow/narrowrevlog.py
--- a/hgext/narrow/narrowrevlog.py
+++ b/hgext/narrow/narrowrevlog.py
@@ -11,17 +11,7 @@
    revlog,
 )
 
-def readtransform(self, text):
-    return text, False
-
-def writetransform(self, text):
-    return text, False
-
-def rawtransform(self, text):
-    return False
-
-revlog.addflagprocessor(revlog.REVIDX_ELLIPSIS,
-                        (readtransform, writetransform, rawtransform))
+revlog.addflagprocessor(revlog.REVIDX_ELLIPSIS, revlog.ellipsisprocessor)
 
 def setup():
     # We just wanted to add the flag processor, which is done at module
diff --git a/mercurial/revlog.py b/mercurial/revlog.py
--- a/mercurial/revlog.py
+++ b/mercurial/revlog.py
@@ -115,6 +115,22 @@
     REVIDX_ISCENSORED: None,
 }
 
+# Flag processors for REVIDX_ELLIPSIS.
+def ellipsisreadprocessor(rl, text):
+    return text, False
+
+def ellipsiswriteprocessor(rl, text):
+    return text, False
+
+def ellipsisrawprocessor(rl, text):
+    return False
+
+ellipsisprocessor = (
+    ellipsisreadprocessor,
+    ellipsiswriteprocessor,
+    ellipsisrawprocessor,
+)
+
 _mdre = re.compile('\1\n')
 def parsemeta(text):
     """return (metadatadict, metadatasize)"""