hgeditor

largefiles: check existence of the file with case awareness of the filesystem

Before this patch, largefiles extension always unlinks largefiles
untracked on the target context in merging/updating after updating
working directory.

For example, it is assumed that the revision X consists of ".hglf/A"
(and "A" implicitly) and revision Y consists of "a" (not ".hglf/A").

In the case of updating from X to Y, largefiles extension tries to
unlink "A" after updating "a" in working directory. This causes
unexpected unlinking "a" on the case insensitive filesystem.

This patch checks existence of the file in the working context with
case awareness of the filesystem to prevent from such unexpected
unlinking.

"lfcommands._updatelfile()" also unlinks target file in the case
"largefile is tracked in the target context, but fails to be fetched".

This patch doesn't apply "repo.dirstate.normalize()" in this case,
because it should be already ensured in the manifest merging that
there is no normal file colliding against any largefiles.

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

# 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 $?