diffutils bug

[Harti Brandt]

Hi all,

diffutils/src/util.c contains the following line:

            execl (pr_program, pr_program, "-h", name, 0);

Unfortunately this line invokes unspecified behaviour according to
C-rules, because for a variadic function the compiler cannot know, that
it has to convert the 0 to a null pointer. This is not a big problem
for systems where sizeof(char *) == sizeof(int) but breaks on other
systems. Note, that it is not enough to write

            execl (pr_program, pr_program, "-h", name, NULL);

because the compiler cannot know that it has to convert the null pointer
constant NULL to a pointer. Whether you write 0 or NULL you must
explicitely convert this to a pointer. The following patch should help:


--- util.c.orig Thu Oct 30 14:38:50 2003
+++ util.c      Thu Oct 30 14:38:19 2003
@@ -215,7 +215,7 @@
                close (pipes[0]);
              }

-           execl (pr_program, pr_program, "-h", name, 0);
+           execl (pr_program, pr_program, "-h", name, (char *)NULL);
            _exit (errno == ENOEXEC ? 126 : 127);
          }
        else

Best regards,
harti
-- 
harti brandt,
http://www.fokus.fraunhofer.de/research/cc/cats/employees/hartmut.brandt/private
address@hidden, address@hidden