bug#8254: race condition in dired.c's scmp function

[Paul Eggert <eggert@cs.ucla.edu>]

On 03/15/2011 12:06 AM, Eli Zaretskii wrote:
> How about a much simpler fix:
> 
>   while (l
>   	 && (c1 = DOWNCASE ((unsigned char) *s1++),
> 	     c2 = DOWNCASE ((unsigned char) *s2++),
> 	     c1 == c2))
>     l--;
> 
> (with suitable declarations of c1 and c2)?  Will that fix the
> undefined behavior?

Yes.  But surely it's better to fix the problem so that
usage of DOWNCASE is less error-prone.  Generally speaking,
code is easier to read and contains fewer errors
when function-like macros act like functions.