view hgeditor @ 28638:44319097e7b9

crecord: re-enable reviewing a patch before comitting it

The "r" option for this feature was copied into Mercurial from
crecord, but the actual implementation never made it into hg until
now. It's a moderately useful feature that allows the user to edit the
patch in a text editor before comitting it for good.

This requires a test, so we must also enable a corresponding testing
'R' option that skips the confirmation dialogue. In addition, we also
need a help text for the editor when reviewing the final patch.

As for why this is a useful feature if we can already edit hunks in an
editor, I would like to offer the following points:

    * editing hunks does not show the entire patch all at once

      ** furthermore, the hunk "tree" in the TUI has no root that could be
         selected for edition

    * it is helpful to be able to see the entire final patch for
      confirmation

      ** within this view, the unselected hunks are hidden, which is
         visusally cleaner

      ** this works as a final review of the complete result, which is
         a bit more difficult to do conceptually via hunk editing

    * this feature was already in crecord, so it was an oversight to
      not bring it to core

    * it works and is consistent with editing hunks

#!/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 $?