(_getopt_internal): Don't recognize an option name as ambiguous if it's a prefix for more than one name but the other struct option values are identical.

posix/getopt.c

@@ -673,7 +673,9 @@ _getopt_internal (argc, argv, optstring, longopts, longind, long_only)
 		pfound = p;
 		indfound = option_index;
 	      }
-	    else
+	    else if (pfound->has_arg != p->has_arg
+		     || pfound->flag != p->flag
+		     || pfound->val != p->val)
 	      /* Second or later nonexact match found.  */
 	      ambig = 1;
 	  }