tentatively fix getopt state corruption for NOFORK applets

1 files changed, 24 insertions, 2 deletions

diff --git a/libbb/vfork_daemon_rexec.c b/libbb/vfork_daemon_rexec.c
index 4e6ecde67..3a386c5c9 100644
--- a/libbb/vfork_daemon_rexec.c
+++ b/libbb/vfork_daemon_rexec.c
@@ -131,12 +131,34 @@ int run_nofork_applet_prime(struct nofork_save_area *old, int applet_no, char **
 
         applet_name = APPLET_NAME(applet_no);
         xfunc_error_retval = EXIT_FAILURE;
-        /*option_mask32 = 0; - not needed */
-        /* special flag for xfunc_die(). If xfunc will "die"
+
+        /* Special flag for xfunc_die(). If xfunc will "die"
          * in NOFORK applet, xfunc_die() sees negative
          * die_sleep and longjmp here instead. */
         die_sleep = -1;
 
+        /* Reset the libc getopt() function, which keeps internal state.
+         *
+         * BSD-derived getopt() functions require that optind be reset to 1 in
+         * order to reset getopt() state.  This used to be generally accepted
+         * way of resetting getopt().  However, glibc's getopt()
+         * has additional getopt() state beyond optind, and requires that
+         * optind be set zero to reset its state.  So the unfortunate state of
+         * affairs is that BSD-derived versions of getopt() misbehave if
+         * optind is set to 0 in order to reset getopt(), and glibc's getopt()
+         * will core ump if optind is set 1 in order to reset getopt().
+         * 
+         * More modern versions of BSD require that optreset be set to 1 in
+         * order to reset getopt().   Sigh.  Standards, anyone?
+         */
+#ifdef __GLIBC__
+        optind = 0;
+#else /* BSD style */
+        optind = 1;
+        /* optreset = 1; */
+#endif
+        /* option_mask32 = 0; - not needed */
+
         argc = 1;
         while (argv[argc])
                 argc++;