--trust-exit-code not working

Hello!,

Firstly, thank you very much to those that contributed the patch; I
truly appreciate it. I haven't been able to make it work in 2.2.0.rc1,
though. I'm not sure whether it's my fault, or the patch', but a 'git
difftool --trust-exit-code' call with vimdiff as the diff tool and
exiting with :cq doesn't seem to make it quit. git simply keeps
pushing files to be diffed. Similarly, if I set meld as the tool and
kill it, git will reopen meld with new files.

Sorry for bringing that up so late; I've been fairly busy. I did test
it some days ago and didn't manage to make it work, either.

Thank you,

Adria