wireprotoserver: ensure that output stream gets flushed on exception
Previously flush was happening due to Python finalizer being run on
`BufferedWriter`. With upgrade to Python 3.11 this started randomly
failing.
My guess is that the finalizer on the raw `FileIO` object may
be running before the finalizer of `BufferedWriter` has a chance to run.
At any rate, since we're not relying on finalizers in the happy case
we should also not rely on them in case of exception.
#require test-repo
$ . "$TESTDIR/helpers-testrepo.sh"
$ cat <<'EOF' > scanhelptopics.py
> import re
> import sys
> if sys.platform == "win32":
> import msvcrt
> import os
> msvcrt.setmode(sys.stdout.fileno(), os.O_BINARY)
> stdout = getattr(sys.stdout, 'buffer', sys.stdout)
> topics = set()
> topicre = re.compile(br':hg:`help ([a-z0-9\-.]+)`')
> for fname in sys.argv:
> with open(fname, 'rb') as f:
> topics.update(m.group(1) for m in topicre.finditer(f.read()))
> for s in sorted(topics):
> stdout.write(b'%s\n' % s)
> EOF
$ cd "$TESTDIR"/..
Check if ":hg:`help TOPIC`" is valid:
(use "xargs -n1 -t" to see which help commands are executed)
$ testrepohg files 'glob:{hgdemandimport,hgext,mercurial}/**/*.py' \
> | sed 's|\\|/|g' \
> | xargs "$PYTHON" "$TESTTMP/scanhelptopics.py" \
> | xargs -n1 hg help --config extensions.phabricator= > /dev/null