view hgeditor @ 5378:8a2915f57dfc

convert: add a mode where mercurial_sink skips empty revisions.

The getchanges function of some converter_source classes can return
some false positives.  I.e. they sometimes claim that a file "foo"
was changed in some revision, even though its contents are still the
same.

convert_svn is particularly bad, but I think this can also happen with
convert_cvs and, at least in theory, with mercurial_source.

For regular conversions this is not really a problem - as long as
getfile returns the right contents, we'll get a converted revision
with the right contents.  But when we use --filemap, this could lead
to superfluous revisions being converted.

Instead of fixing every converter_source, I decided to change
mercurial_sink to work around this problem.

When --filemap is used, we're interested only in revisions that touch
some specific files.  If a revision doesn't change any of these files,
then we're not interested in it (at least for revisions with a single
parent; merges are special).

For mercurial_sink, we abuse this property and rollback a commit if
the manifest text hasn't changed.  This avoids duplicating the logic
from localrepo.filecommit to detect unchanged files.

#!/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" 1 2 3 6 15 # HUP INT QUIT ABRT TERM

HGTMP="${TMPDIR-/tmp}/hgeditor.$RANDOM.$RANDOM.$RANDOM.$$"
(umask 077 && mkdir "$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 $?