When passing a command-line to call an external diff command to the
difftool, we must be prepared for paths containing special characters,
e.g. backslashes in the temporary directory's path on Windows.
This patch is needed in preparation for the next commit, which will
make the MinGW version of Git *not* rewrite TMP to use forward slashes
instead of backslashes.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>