Re: [PATCH 3/2] dir.c: fix dir re-inclusion rules with "NODIR" and "MUSTBEDIR"

> On Fri, Mar 18, 2016 at 11:51 AM, Durham Goode <durham@fb.com> wrote:
>> On 3/17/16 4:49 PM, Junio C Hamano wrote:
>>> Thanks for these 5 patches, two of which need to be discarded ;-).
>>> I think you can pick either one of 1/2, pick the one that says
>>> "non-NULL" (as opposed to "something") in the log message for 2/2.
>>>
>>> Durham, does it fix your issues if you apply the 1/2 and 2/2 (but
>>> not 3/2) on top of 2.8-rc?
>>>
>>> Duy, how comfortable are you with the idea of including this two in
>>> 2.8 final?  We have long passed the final -rc, and while it is
>>> probably OK to prolong the cycle and do another -rc, we cannot keep
>>> going like "oops, there is another thing discovered by somebod new"
>>> forever.
>>>
>>> Thanks.
>> Patches 1+2 fix the repro steps in the report, yes.  But I've found another
>> case that produces different results in 2.8 than in 2.7:
>>
>> Given a repo with files:
>>
>> dir1/dir2/show/file
>> dir1/dir2/hide/file
>>
>> and a sparse-checkout of
>>
>> /*
>> /dir1/dir2/show
>> !/dir1/dir2/
> I would say this is "undefined behavior" patterns. The intention of
> "!" pattern is to revert a subset of a matched pattern, e.g.
> !/dir1/dir2/show/something. Combining lines 2 and 3 together,
> "!dir1/dir2/" is not only supposed to revert dir1/dir2/show entirely,
> but extend the reversion outside of it. At least to me that's not
> intended.

>
> Skipping that tricky pair, the pairs "/*" and "!/dir1/dir2/" means
> "exclude everything except dir1/dir2" (in .gitignore sense) or
> "include everything except dir1/dir2" in sparse checkout sense. Which
> results in empty worktree. 1+2 trips when the trailing slash in the
> last rule exists and includes both files in show/hide. Patch 3/2 fixes
> the tripping and exclude both. If the last rule is "!/dir1/dir2" then
> 1+2 results in empty worktree as well.
>