hgeditor

Disable automatic line endings conversion on windows

The rationale behind this is that such conversion implies a particular
situation in which all files in the repo are terminated by only LF. This
is documented nowhere and it bit me sharply when I upgraded.

Furthermore, it works on the assumption that a file containing no NULL
characters are actually a text file. Therefore it cannot guarantee that
no binary file will be harmed in the process.

Currently, if a file already contains CRLF line endings when it is
copied to the working dir from the repo, then the version in the working
dir will be corrupted by an extra CR.

I'm working on a patch that will turn this into a warning. But as a side
effect, committing such a file back will strip it from its CR.

In all case, unrequested data modification can occur under the feet of
the user, which is bad(tm), ihmo.

#!/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"

CHECKSUM=`md5sum "$HGTMP/msg"`
if [ -s "$HGTMP/diff" ]; then
    $EDITOR "$HGTMP/msg" "$HGTMP/diff" || exit $?
else
    $EDITOR "$HGTMP/msg" || exit $?
fi
echo "$CHECKSUM" | md5sum -c >/dev/null 2>&1 && exit 13

mv "$HGTMP/msg" "$1"

exit $?