On Wed, Apr 15, 2009 at 12:40:26AM +0700, Robert Elz wrote:
> Date: Tue, 14 Apr 2009 16:11:13 +0200
> From: Joerg Sonnenberger <jo...@britannica.bec.de>
> Message-ID: <20090414141113.gd...@britannica.bec.de>
>
> | toupper() gets u_char arguments, not int. This cast is simply wrong.
>
> According to TFM ...
>
> SYNOPSIS
> #include <ctype.h>
>
> int
> toupper(int c);
>
> and
>
> CAVEATS
> The argument to toupper() must be EOF or representable as an unsigned
> char; otherwise, the behavior is undefined.
>
> If EOF is to be a valid parameter to toupper(), then the arg type
> cannot be u_char - however much you'd like it to be.
The cast added is definitely the wrong one.
The 'char' value 'row[...]' must not get promoted to a negative value
when used in toupper() - otherwise a -ve value can result and the behaviour
is undefined.
Looking at that function - it is absolutely horrid.
It almost contains:
foo[strlen(foo)] = 0;
David
--
David Laight: da...@l8s.co.uk
