Re: printf: %ls or %S does not work when string is of length 1.

[Corinna Vinschen <vinschen at redhat dot com>]

On Aug 27 14:31, Jeff Johnston wrote:
> Corinna Vinschen wrote:
>>
>>
>> I tracked this down to a problem in the function _wcsrtombs_r.
>>
>> The condition to write a converted character into the destination string
>> and to continue the loop is (wcsrtombs.c, line 48):
>>
>>   if (n <= len - bytes && bytes < len)
>>
>> The second half of this condition is wrong, AFAICS.  First of all, it
>> should be bytes <= len instead of bytes < len.  Second, this part of the
>> condition is already catched by the first part of the condition:
>>
>>   n <= len - bytes  <==>  n + bytes <= len
>>
>> with n always >= 0, bytes is always <= len if n + bytes is <= len.  So
>> the condition is redundant.
>>
>>   
> Thanks for looking at this Corinna.
>
> Actually, the second part is needed because the first equation is unsigned. 
>  Let's say len is 1 but bytes is 2.  len - bytes is (unsigned)-1.  We don't 
> want to write at this point.  Thus, we make the additional check that bytes 
> is actually <= len.  I just modified your change and checked it in.

Thank you.  But...  wouldn't

  if (n + bytes <= len)

have the same result?


Corinna

-- 
Corinna Vinschen
Cygwin Project Co-Leader
Red Hat