diff -r a407fe56d6e8 -r c5e1cc0b4c77 mercurial/revlog.py
--- a/mercurial/revlog.py	Fri Apr 30 03:09:16 2021 +0200
+++ b/mercurial/revlog.py	Fri Apr 30 03:19:45 2021 +0200
@@ -1299,7 +1299,7 @@
         if isinstance(id, int):
             # rev
             return self.node(id)
-        if len(id) == 20:
+        if len(id) == self.nodeconstants.nodelen:
             # possibly a binary node
             # odds of a binary node being all hex in ASCII are 1 in 10**25
             try: