view hgeditor @ 34639:a568a46751b6

selectors2: do not use platform.system()

`platform.system()` may have a side effect spawning a shell executing
`uname -p`, which may print a warning when the current directory is removed:

  shell-init: error retrieving current directory: getcwd: cannot access parent directories: No such file or directory

This patch changes selectors2 to test the `sys.platform` string, which is a
much safer way to detect Jython.

Jython's `sys.platform` looks like this:

  Jython 2.7.1 (default:0df7adb1b397, Jun 30 2017, 19:02:43)
  [OpenJDK 64-Bit Server VM (Oracle Corporation)] on java1.8.0_144
  Type "help", "copyright", "credits" or "license" for more information.
  >>> import sys
  >>> sys.platform
  'java1.8.0_144 ( ==linux2 for targets )'

Differential Revision: https://phab.mercurial-scm.org/D1018

#!/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 $?