view hgeditor @ 42136:10a6725dca6e

compression: introduce an official `zstd-revlog` requirement

This requirement supersedes `exp-compression-zstd`. However, we keep support for
the old requirement.

Strictly speaking, we do not need to add a new requirement, there are no logic
change making "new" repo incompatible with mercurial client using a version
that support `exp-compression-zstd`.

The choice to introduce a new requirement is motivated by the following:

* The previous requirement was explicitly "experimental". Using it by default
  could confuse users.

* adding support for a hypothetical third compression engine will requires new
  code, and will comes with its own requirement tool.

* We won't use it as the default for a while since I do not think we support
  zstd on all platform. I can imagine we'll gain another (unrelated but on my
  default) requirement by the time we turn this zstd by default.

#!/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 $?