diff -r 4292bed8da7c -r 47ffc754989a mercurial/revlog.py
--- a/mercurial/revlog.py	Mon May 03 12:21:15 2021 +0200
+++ b/mercurial/revlog.py	Mon May 03 12:21:25 2021 +0200
@@ -2268,9 +2268,6 @@
             len(serialized_sidedata),
         )
 
-        if self._format_version != REVLOGV2:
-            e = e[:8]
-
         self.index.append(e)
         entry = self.index.entry_binary(curr)
         if curr == 0: