Bug#22541: Better info on snprintf bug

[Kevin Ryde <user42@zip.com.au>]

Giuliano P Procida <gpp10@cam.ac.uk> writes:
>
> Here is some more! Please ignore previous witterings which indicated
> that I had forgotten that size_t is unsigned!
> 
> #include <stdio.h>
> #include <stdarg.h>
> int main () {
>   char b[9];
>   int stat;
>   int  i;
>   for (i = 0; i < 5; ++i) {
>     stat = snprintf (b, i, "foo");
>     printf ("i %u, got %d, exp %d\n", i, stat, (size_t) i < 4 ? -1 : 3);
>   }
>   for (i = -1; i < 5; ++i) {
>     stat = snprintf (b, i, "foo");
>     printf ("i %u, got %d, exp %d\n", i, stat, (size_t) i < 4 ? -1 : 3);
>   }
>   return 0;
> }
> 
> i 0, got 0, exp -1    <- sick
> i 1, got -1, exp -1   <- works OK
> i 2, got -1, exp -1
> i 3, got -1, exp -1
> i 4, got 3, exp 3
> i 4294967295, got 3, exp 3 <- throw in MAX_UINT
> i 0, got 0, exp -1    <- sick
> i 1, got 3, exp -1    <- BROKEN this time
> i 2, got -1, exp -1
> i 3, got -1, exp -1
> i 4, got 3, exp 3


I just gave snprintf() a try in libc6 2.1.2-11 and it now returns 3 in
all the above cases, which is correct per the change to ISO C9x
described in the info docs for snprintf(), so I think this bug could
be closed.