Fix MinGW-Bug [2445962]; (reported by Keishi Suenaga).

winsup/mingw/mingwex/getopt.c

@@ -87,6 +87,14 @@ enum
 
 int optopt = getopt_unknown;	/* return value for option being evaluated   */
 
+/* Some BSD applications expect to be able to reinitialise `getopt' parsing
+ * by setting a global variable called `optreset'.  We provide an obfuscated
+ * API, which allows applications to emulate this brain damage; however, any
+ * use of this is non-portable, and is strongly discouraged.
+ */
+#define optreset  __mingw_optreset
+int optreset = 0;
+
 static __inline__
 int getopt_missing_arg( const CHAR *optstring )
 {
@@ -313,7 +321,7 @@ int getopt_parse( int mode, getopt_std_args, ... )
   static const CHAR *nextchar = NULL;
   static int optmark = 0;
 
-  if( optind < optbase )
+  if( (optreset |= (optind < 1)) || (optind < optbase) )
   {
     /* POSIX does not prescribe any definitive mechanism for restarting
      * a `getopt' scan, but some applications may require such capability.
@@ -325,7 +333,25 @@ int getopt_parse( int mode, getopt_std_args, ... )
      * adjusting all of the internal placeholders to one less than the
      * adjusted `optind' value, (but never to less than zero).
      */
-    optmark = optbase = argind = (optind > 0) ? optind - 1 : 0;
+    if( optreset )
+    {
+      /* User has explicitly requested reinitialisation...
+       * We need to reset `optind' to it's normal initial value of 1,
+       * to avoid a potential infinitely recursive loop; by doing this
+       * up front, we also ensure that the remaining placeholders will
+       * be correctly reinitialised to no less than zero.
+       */
+      optind = 1;
+
+      /* We also need to clear the `optreset' request...
+       */
+      optreset = 0;
+    }
+
+    /* Now, we may safely reinitialise the internal placeholders, to
+     * one less than `optind', without fear of making them negative.
+     */
+    optmark = optbase = argind = optind - 1;
     nextchar = NULL;
   }