Re: [PATCH v2] diff -c -p: do not die on submodules

From: Alex Riesen <raa.lkml@gmail.com>
Date: Apr 29, 2009, 22:19 UTC
Message-ID: <81b0412b0904291519m41035200n408b6ab409eed127@mail.gmail.com>
In-Reply-To: <alpine.DEB.1.00.0904300011140.10279@pacific.mpi-cbg.de>

2009/4/30 Johannes Schindelin <Johannes.Schindelin@gmx.de>:

Show 30 quoted lines

> Hi,
>
> On Wed, 29 Apr 2009, Alex Riesen wrote:
>
>> 2009/4/29 Junio C Hamano <gitster@pobox.com>:
>> > +
>> > +       if (S_ISGITLINK(mode)) {
>> > +               blob = xmalloc(100);
>> > +               *size = snprintf(blob, 100,
>> > +                                "Subproject commit %s\n", sha1_to_hex(sha1));
>>
>> snprintf returns a signed value. It also has a bad record of returning
>> negative values for obscure reasons (on obscure platforms, admittedly).
>>
>> For this particular case,
>>
>>   strcpy(blob, "Subproject commit ");
>>   strcat(blob, sha1_to_hex(sha1));
>>   strcat(blob, "\n");
>>   *size = strlen(blob); /* that's a constant */
>>
>> could be considered.
>
> Actually, we know _exactly_ the size of the thing.  It is 18+40+1.  But I
> think that *size wants to have the size, not the length.  So add 1.
>
> In any case, I don't think that we have to jump through hoops here:
> snprintf() is _most_ unlikely to return something negative here.  So I'd
> say that readability trumps paranoia here.
>

http://www.google.com/search?q=snprintf+negative+return+value

First link: http://bytes.com/groups/c/590845-snprintf-return-value

Look for "(Windows, mingw)"