Re: [PATCH v12 5/5] read-cache: speed up has_dir_name (part 2)

> SZEDER Gábor <szeder.dev@gmail.com> writes:
> 
>>> +				 * last: xxx/yy-file (because '-' sorts before '/')
>>> +				 * this: xxx/yy/abc
>>
>> This is problematic, because the index can already contain 'xxx/yy' as
>> a file, when adding 'xxx/yy/abc', but since 'xxx/yy' as a file sorts
>> before 'xxx/yy-file', the short-circuiting here doesn't see it and
>> thus leaves the d-f collision undetected.  Consequently, even Git
>> porcelain commands can create tree objects with duplicate entries, as
>> demonstrated in the tests below.
> 
> Yeah, the "optimization" is quite bogus.  Thanks for catching it.
>