diff -r 9d569983668b -r 61134a232d00 mercurial/manifest.py
--- a/mercurial/manifest.py	Wed Jan 08 11:33:01 2020 -0500
+++ b/mercurial/manifest.py	Thu Apr 02 16:02:21 2020 -0400
@@ -1432,6 +1432,7 @@
                 set = super(manifestfulltextcache, self).__setitem__
                 # ignore trailing data, this is a cache, corruption is skipped
                 while True:
+                    # TODO do we need to do work here for sha1 portability?
                     node = fp.read(20)
                     if len(node) < 20:
                         break