[PATCH] ussd: Fix text of RELEASE COMPLETE

[noselasd at fiane.dyndns.org]

On 10/08/2013 11:51 AM, Alexander Huemer wrote:
> On Tue, Oct 08, 2013 at 11:27:49AM +0200, Holger Hans Peter Freyther wrote:
>> On Sun, Oct 06, 2013 at 09:55:09PM +0200, Alexander Huemer wrote:
>>> Before the assigned value (0xFF) was truncated, reg->text[0] is of
>>> type char. A corresponding test for the same value in openbsc could
>>> only fail.
>>
>> Can you please explain?
>
> char is an signed 8bit type, so the maximum value is 0x7F. Well, at
> least usually. As I read, ANSI C does not dictate whether a variable
> declared as 'char' is signed or unsigned, gcc though defaults to signed.
> Excerpt from limits.h:
>
> [...]
> #  define SCHAR_MAX     127
> [...]
> #  ifdef __CHAR_UNSIGNED__ (this is not the case normally)
> [...]
> #   define CHAR_MAX     SCHAR_MAX
> [...]
>
> Example program:
>
> int main(void)
> {
>          char c = 0xFF;
>
>          if (c == 0xFF)
>                  return 0;
>
>          return 1;
> }
And this is because:

   char c = 0xff;
   c == 0xff;
   ^^     ^^
   |    an int
   |
promoted to int and sign extended in this expression

So it's really -1 == 255

c == (char)0xff; would be ok though