bug#18680: [PATCH] Check if argv[0] is NULL in scm_boot_guile to avoid segfault

[Mark H Weaver]

Nala Ginrut <nalagin...@gmail.com> writes:

> This patch is for master branch, but the bug also appears in the
> current stable-2.0 I think.
>
> With the recent patch from Eli Zaretskii, there'd be one more step for 
> argv[0]:
> scm_i_mirror_backslashes (argv[0]);
>
> But this cause my program segfault, since I have such line:
> scm_boot_guile(0, {NULL}, &guilemain, NULL);
>
> According to C11, it's allowed[1].
> argv[argc] should be NULL.
> If the value of argc is greater than zero, the string pointed to by argv[0]
> represents the program name. But if argc is zero, argv[0] will be NULL, so
> we have to check it first to avoid segfault.

Fixed in b9ace68613395fda26f3f3d7dc2ac9bc52cd7f2a on the stable-2.0
branch.  It'll go into master on the next merge.

     Thanks,
       Mark