AIX bug malloc(0)

[Winona Brown]

make with aix5.1 compiler vac5 (xlc) was failing in checks until I added 
   if (n == 0)
       n = 1;
before calling malloc.

The technical reference for AIX 5L 5.1 says:

If the malloc or valloc subroutine is called with a size of 0, the subroutine
returns a null pointer

The better way to fix this would probably be to allow a NULL being returned
if malloc(0) was called.  

gnupg-1.0.7/util/memory.c

Winona