Re: [PATCH] compat: convert modes to use portable file type values

From: Junio C Hamano <gitster@pobox.com>
Date: Dec 1, 2014, 20:09 UTC
Message-ID: <xmqq7fybp1xb.fsf@gitster.dls.corp.google.com>
In-Reply-To: <CAEvUa7nsz1UX5+qakPGW=wTR_VRJU3r+VkgVt9qiCDUz30MweA@mail.gmail.com>

David Michael <fedora.dm0@gmail.com> writes:

Show 16 quoted lines

>> Huh?  I am confused.  Since when is it legal to give NULL as statbuf
>> to (l)stat(2)?
>>
>> Wouldn't something like this be sufficient and necessary?
>>
>>         int rc = stat(path, buf);
>>         if (rc)
>>                 return rc;
>>
>> That is, let the underlying stat(2) diagnose any and all problems
>> (and leave clues in errno) and parrot its return value to the caller
>> to signal the failure?
>
> Alright, it wasn't immediately clear to me from the OpenGroup page on
> stat() if that would always be safe.  I will just test the return code
> in v2.

It is irrelevant if that is safe or not. As long as we are emulating the underlying stat(), whether it is unsafe for stat(), we should just throw whatever the user throws at us at the underlying stat() and let it behave as if our emulation layer were not there.

Which is what the above snippet does.