store: return just one filename in walk functions Various walk functions return `(revlog_type, decoded, encoded)` where decoded could be None. But no-one cares about `encoded` and expects `unencoded` to be present, except verify (because this can only happen with old repo formats). Simplify all this by either failing outright if a decoding a filename fails (instead of almost certainly failing with a type error due to treating None as a bytes), or skipping the filename but providing in an out argument for hg verify. Differential Revision: https://phab.mercurial-scm.org/D11248

--- a/mercurial/revlogutils/rewrite.py	Sun Aug 01 10:57:21 2021 -0400
+++ b/mercurial/revlogutils/rewrite.py	Mon Aug 02 08:05:13 2021 -0400
@@ -824,7 +824,7 @@
     with context():
         files = list(
             (file_type, path)
-            for (file_type, path, _e, _s) in repo.store.datafiles()
+            for (file_type, path, _s) in repo.store.datafiles()
             if path.endswith(b'.i') and file_type & store.FILEFLAGS_FILELOG
         )