[pechtcha: Bug in scanf &Co (Was Re: Error message from antiword since upgrade to cygwin 1.5.10)]

[Jeff Johnston]

I have checked in a patch.  When the 0 was read, some flags were cleared, 
however, these flags should have been reset again when the x was found since the 
0 was actually part of the hex prefix and not a digit.

-- Jeff J.

Christopher Faylor wrote:
> ----- Forwarded message from Igor Pechtchanski <pechtcha> -----
> 
> From: Igor Pechtchanski
> To: cygwin
> Cc: "Gerrit P. Haase"
> Subject: Bug in scanf &Co (Was Re: Error message from antiword since upgrade to cygwin 1.5.10)
> Date: Wed, 2 Jun 2004 14:04:33 -0400 (EDT)
> In-Reply-To: <Pine.GSO.4.58.0406021327090.18478@slinky.cs.nyu.edu>
> 
> On Wed, 2 Jun 2004, Igor Pechtchanski wrote:
> 
> 
>>On Wed, 2 Jun 2004, Gerrit P. Haase wrote:
>>
>>[snip]
>>
>>>Everything works ok with cygwin-1.5.9.  I'll try to recompile with
>>>1.5.10 later, maybe that helps...
>>>
>>>Gerrit
>>
>>Try the attached patch.  FWIW, it seems like there's a bug here, but
>>sscanf used to mask it.  Was there a change in the sscanf implementation
>>since 1.5.9?
>>        Igor
> 
> 
> Never mind.  This is a bug in the newlib scanf family implementation
> (actually, in __svfscanf_r in libc/stdio/vfscanf.c) that causes it to read
> strings of the form 0x0+ incorrectly.  Attached is a testcase that
> demonstrates the bug.  I suspect the following change:
> 
> 2004-04-21  J"orn Rennecke
> 
>         * libc/stdio/vfscanf.c (NNZDIGITS): New define.
>         (__svfscanf_r): In integer conversions, leave out leading zeroes
>         which are not part of a base prefix.
>         Keep track of width truncation to fit into buf, not counting left-out
>         zeroes against width till the truncation has been compensated for.
> 
> #include <stdlib.h>
> #include <stdio.h>
> 
> int main(char ac, char *av[]) {
>   const char *str1 = "0x1 0x0 0x3";
>   const char *str2 = "0x1 0x2 0x3";
>   unsigned int i,j,k;
>   sscanf(str1, "%x %x %x", &i, &j, &k);
>   printf("Values are: %x %x %x\n", i, j, k);
>   sscanf(str2, "%x %x %x", &i, &j, &k);
>   printf("Values are: %x %x %x\n", i, j, k);
> }
> 
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