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
#require serve
$ hg clone http://localhost:$HGPORT/ copy
abort: * (glob)
[100]
$ test -d copy
[1]
$ "$PYTHON" "$TESTDIR/dumbhttp.py" -p $HGPORT --pid dumb.pid
$ cat dumb.pid >> $DAEMON_PIDS
$ hg clone http://localhost:$HGPORT/foo copy2
abort: HTTP Error 404: * (glob)
[100]
$ killdaemons.py