Re: Change in .gitignore handling: intended or bug?

From: Duy Nguyen <pclouds@gmail.com>
Date: Mar 5, 2016, 00:43 UTC
Message-ID: <CACsJy8BZm9pFdR+Njst7qZ1UnHUL9XpigM5pW+CLEicOc7ra8g@mail.gmail.com>
In-Reply-To: <xmqq4mcm17b4.fsf@gitster.mtv.corp.google.com>

On Sat, Mar 5, 2016 at 12:28 AM, Junio C Hamano <gitster@pobox.com> wrote:

Show 24 quoted lines

> Duy Nguyen <pclouds@gmail.com> writes:
>
>> On Fri, Mar 4, 2016 at 6:56 PM, Kevin Daudt <me@ikke.info> wrote:
>>> Verified that it's different in 2.7.0, but 2.7.2 gives expected output.
>>
>> Thanks. 2.7.1 reverts the faulty commit from 2.7.0 that generated two
>> other regression reports before this one. I guess it's all good then
>> (except for the people still on 2.7.0)
>
> Are we good at 2.8.0-rc0, too?  Somehow I had an impression that we
> queued "another attempt to do it differently" or something.
>
>  ... goes and looks ...
>
>     $ rungit maint status -suall
>     ?? baz/quux/corge/wibble.txt
>     ?? baz/quux/grault.txt
>     ?? foo/bar.txt
>     $ rungit master status -suall
>     ?? baz/quux/corge/wibble.txt
>     ?? baz/quux/grault.txt
>     ?? baz/waldo.txt
>     ?? foo/bar.txt
>     ?? foo/garply.txt

If you swap a60ea8f and bac65a2 so that we can have tracing even without the problematic commit a60ea8f (dir.c: fix match_pathname() - 2016-02-15). Without a60ea8f I got

GIT_TRACE_EXCLUDE=1 ~/w/git/temp/git status -suall 2>&1 >/dev/null
|grep waldo
07:25:05.639445 dir.c:952               exclude: baz/waldo.txt vs * at
line 1 => yes

(meaning, baz/waldo.txt matches "*" rule and is decided to be excluded)

with a60ea8f

> /tmp/abc $ GIT_TRACE_EXCLUDE=1 ~/w/git/temp/git status -suall 2>&1 >/dev/null |grep waldo

07:25:24.425125 dir.c:952 exclude: baz/waldo.txt vs /baz at line 4 => no

the decision is not taken earlier from line "!/baz" and it's decided to be re-included. Which I would argue is the correct thing because you ask to re-include the whole directory "baz". It should behave this way because exclude rules without '!' behave this way.

Because positive any negative rules can be nested, by adding a rule to reinclude what's inside baz..

    *
    !/foo
    !/foo/bar.txt
    !/baz
    /baz/*
    !/baz/quux
    !/baz/quux/**/*

you'll get baz/waldo.txt excluded.

Yes it's a behavior change. I think the old behavior is unintended. But it's probably out there long enough that many .gitignore files may rely on it and by making it right, I break them. Whether to revert the series is up to you. Let me know if I should send the revert patch.

-- 
Duy