hgeditor

demandimport: fix a crash in LazyFinder.__delattr__

I was tinkering with `with hgdemandimport.deactivated()` wrapped around loading
the keyring module, and got spew that seemed to be confirmed by PyCharm.  But I
can't believe we haven't seen this before (and phabricator uses the same
pattern):

    ** Unknown exception encountered with possibly-broken third-party extension "mercurial_keyring" 1.4.3 (keyring 23.11.0, backend unknown)
    ** which supports versions unknown of Mercurial.
    ** Please disable "mercurial_keyring" and try your action again.
    ** If that fixes the bug please report it to https://foss.heptapod.net/mercurial/mercurial_keyring/issues
    ** Python 3.9.15 (main, Oct 13 2022, 04:28:25) [GCC 7.5.0]
    ** Mercurial Distributed SCM (version 6.3.1)
    ** Extensions loaded: absorb, attorc 20220315, blackbox, eol, extdiff, fastannotate, lfs, mercurial_keyring 1.4.3 (keyring 23.11.0, backend unknown), phabblocker 20220315, phabricator 20220315, purge, rebase, schemes, share, show, strip, uncommit
    Traceback (most recent call last):
      File "/usr/local/bin/hg", line 59, in <module>
        dispatch.run()
      File "/usr/local/lib/python3.9/site-packages/mercurial/dispatch.py", line 143, in run
        status = dispatch(req)
      File "/usr/local/lib/python3.9/site-packages/mercurial/dispatch.py", line 232, in dispatch
        status = _rundispatch(req)
      File "/usr/local/lib/python3.9/site-packages/mercurial/dispatch.py", line 276, in _rundispatch
        ret = _runcatch(req) or 0
      File "/usr/local/lib/python3.9/site-packages/mercurial/dispatch.py", line 451, in _runcatch
        return _callcatch(ui, _runcatchfunc)
      File "/usr/local/lib/python3.9/site-packages/mercurial/dispatch.py", line 461, in _callcatch
        return scmutil.callcatch(ui, func)
      File "/usr/local/lib/python3.9/site-packages/mercurial/scmutil.py", line 153, in callcatch
        return func()
      File "/usr/local/lib/python3.9/site-packages/mercurial/dispatch.py", line 441, in _runcatchfunc
        return _dispatch(req)
      File "/usr/local/lib/python3.9/site-packages/mercurial/dispatch.py", line 1265, in _dispatch
        return runcommand(
      File "/usr/local/lib/python3.9/site-packages/mercurial/dispatch.py", line 899, in runcommand
        ret = _runcommand(ui, options, cmd, d)
      File "/usr/local/lib/python3.9/site-packages/mercurial/dispatch.py", line 1277, in _runcommand
        return cmdfunc()
      File "/usr/local/lib/python3.9/site-packages/mercurial/dispatch.py", line 1263, in <lambda>
        d = lambda: util.checksignature(func)(ui, *args, **strcmdopt)
      File "/usr/local/lib/python3.9/site-packages/mercurial/util.py", line 1880, in check
        return func(*args, **kwargs)
      File "/root/mercurial_keyring/mercurial_keyring/mercurial_keyring.py", line 962, in cmd_keyring_check
        user, pwd, source, final_url = handler.get_credentials(
      File "/root/mercurial_keyring/mercurial_keyring/mercurial_keyring.py", line 497, in get_credentials
        keyring_pwd = password_store.get_http_password(keyring_url, actual_user)
      File "/root/mercurial_keyring/mercurial_keyring/mercurial_keyring.py", line 287, in get_http_password
        return self._read_password_from_keyring(
      File "/root/mercurial_keyring/mercurial_keyring/mercurial_keyring.py", line 335, in _read_password_from_keyring
        keyring = import_keyring()
>> `with hgdemandimport.deactivated()` inserted here
      File "/root/mercurial_keyring/mercurial_keyring/mercurial_keyring.py", line 120, in import_keyring
        return _import_keyring()
      File "/root/mercurial_keyring/mercurial_keyring/mercurial_keyring.py", line 133, in _import_keyring
        mod, was_imported_now = meu.direct_import_ext(
      File "/usr/lib/python3.9/site-packages/mercurial_extension_utils.py", line 1381, in direct_import_ext
        __import__(module_name)
      File "<frozen importlib._bootstrap>", line 1007, in _find_and_load
      File "<frozen importlib._bootstrap>", line 986, in _find_and_load_unlocked
      File "<frozen importlib._bootstrap>", line 680, in _load_unlocked
      File "/usr/local/lib/python3.9/site-packages/hgdemandimport/demandimportpy3.py", line 46, in exec_module
        self.loader.exec_module(module)
      File "/usr/lib/python3.9/site-packages/keyring/__init__.py", line 1, in <module>
        from .core import (
      File "<frozen importlib._bootstrap>", line 1007, in _find_and_load
      File "<frozen importlib._bootstrap>", line 986, in _find_and_load_unlocked
      File "<frozen importlib._bootstrap>", line 680, in _load_unlocked
      File "/usr/local/lib/python3.9/site-packages/hgdemandimport/demandimportpy3.py", line 46, in exec_module
        self.loader.exec_module(module)
      File "/usr/lib/python3.9/site-packages/keyring/core.py", line 11, in <module>
        from . import backend, credentials
      File "<frozen importlib._bootstrap>", line 1007, in _find_and_load
      File "<frozen importlib._bootstrap>", line 986, in _find_and_load_unlocked
      File "<frozen importlib._bootstrap>", line 680, in _load_unlocked
      File "/usr/local/lib/python3.9/site-packages/hgdemandimport/demandimportpy3.py", line 46, in exec_module
        self.loader.exec_module(module)
      File "/usr/lib/python3.9/site-packages/keyring/backend.py", line 13, in <module>
        from .py312compat import metadata
      File "<frozen importlib._bootstrap>", line 1007, in _find_and_load
      File "<frozen importlib._bootstrap>", line 986, in _find_and_load_unlocked
      File "<frozen importlib._bootstrap>", line 680, in _load_unlocked
      File "/usr/local/lib/python3.9/site-packages/hgdemandimport/demandimportpy3.py", line 46, in exec_module
        self.loader.exec_module(module)
      File "/usr/lib/python3.9/site-packages/keyring/py312compat.py", line 10, in <module>
        import importlib_metadata as metadata  # type: ignore
      File "<frozen importlib._bootstrap>", line 1007, in _find_and_load
      File "<frozen importlib._bootstrap>", line 986, in _find_and_load_unlocked
      File "<frozen importlib._bootstrap>", line 680, in _load_unlocked
      File "/usr/local/lib/python3.9/site-packages/hgdemandimport/demandimportpy3.py", line 46, in exec_module
        self.loader.exec_module(module)
      File "/usr/lib/python3.9/site-packages/importlib_metadata/__init__.py", line 715, in <module>
        class MetadataPathFinder(NullFinder, DistributionFinder):
      File "/usr/lib/python3.9/site-packages/importlib_metadata/_compat.py", line 24, in install
        disable_stdlib_finder()
      File "/usr/lib/python3.9/site-packages/importlib_metadata/_compat.py", line 43, in disable_stdlib_finder
        del finder.find_distributions
      File "/usr/local/lib/python3.9/site-packages/hgdemandimport/demandimportpy3.py", line 88, in __delattr__
        return delattr(object.__getattribute__(self, "_finder"))
    TypeError: delattr expected 2 arguments, got 1

#!/bin/sh
#
# This is an example of using HGEDITOR to create of diff to review the
# changes while committing.

# If you want to pass your favourite editor some other parameters
# only for Mercurial, modify this:
case "${EDITOR}" in
    "")
        EDITOR="vi"
        ;;
    emacs)
        EDITOR="$EDITOR -nw"
        ;;
    gvim|vim)
        EDITOR="$EDITOR -f -o"
        ;;
esac


HGTMP=""
cleanup_exit() {
    rm -rf "$HGTMP"
}

# Remove temporary files even if we get interrupted
trap "cleanup_exit" 0 # normal exit
trap "exit 255" HUP INT QUIT ABRT TERM

HGTMP=$(mktemp -d ${TMPDIR-/tmp}/hgeditor.XXXXXX)
[ x$HGTMP != x -a -d $HGTMP ] || {
  echo "Could not create temporary directory! Exiting." 1>&2
  exit 1
}

(
    grep '^HG: changed' "$1" | cut -b 13- | while read changed; do
        "$HG" diff "$changed" >> "$HGTMP/diff"
    done
)

cat "$1" > "$HGTMP/msg"

MD5=$(which md5sum 2>/dev/null) || \
    MD5=$(which md5 2>/dev/null)
[ -x "${MD5}" ] && CHECKSUM=`${MD5} "$HGTMP/msg"`
if [ -s "$HGTMP/diff" ]; then
    $EDITOR "$HGTMP/msg" "$HGTMP/diff" || exit $?
else
    $EDITOR "$HGTMP/msg" || exit $?
fi
[ -x "${MD5}" ] && (echo "$CHECKSUM" | ${MD5} -c >/dev/null 2>&1 && exit 13)

mv "$HGTMP/msg" "$1"

exit $?