*: move getopt reset code to better place(s)

1 files changed, 23 insertions, 4 deletions

diff --git a/libbb/getopt32.c b/libbb/getopt32.c
index 2452eb0a5..80d5d2822 100644
--- a/libbb/getopt32.c
+++ b/libbb/getopt32.c
@@ -473,11 +473,30 @@ getopt32(char **argv, const char *applet_opts, ...)
                 }
         }
 
-        /* In case getopt32 was already called, reinit some state */
+        /* In case getopt32 was already called:
+         * reset the libc getopt() function, which keeps internal state.
+         *
+         * BSD-derived getopt() functions require that optind be set 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 to 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 dump 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;
-        /* optarg = NULL; opterr = 0; optopt = 0; ?? */
+        /* optreset = 1; */
+#endif
+        /* optarg = NULL; opterr = 0; optopt = 0; - do we need this?? */
 
-        /* Note: just "getopt() <= 0" will not work good for
+        /* Note: just "getopt() <= 0" will not work well for
          * "fake" short options, like this one:
          * wget $'-\203' "Test: test" http://kernel.org/
          * (supposed to act as --header, but doesn't) */
@@ -487,7 +506,7 @@ getopt32(char **argv, const char *applet_opts, ...)
 #else
         while ((c = getopt(argc, argv, applet_opts)) != -1) {
 #endif
-                c &= 0xff; /* fight libc's sign extends */
+                c &= 0xff; /* fight libc's sign extension */
  loop_arg_is_opt:
                 for (on_off = complementary; on_off->opt != c; on_off++) {
                         /* c==0 if long opt have non NULL flag */