Require exact match of vm arguments.

runtime/bin/main.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include <stdlib.h>
 #include <string.h>
 #include <stdio.h>
 
 #include "include/dart_api.h"
 #include "include/dart_debugger_api.h"
@@ skipping 245 matching lines @@
 };
 
 
 static bool ProcessMainOptions(const char* option) {
   int i = 0;
   const char* name = main_options[0].option_name;
   int option_length = strlen(option);
   while (name != NULL) {
     int length = strlen(name);
     if ((option_length >= length) && (strncmp(option, name, length) == 0)) {
-      if (!main_options[i].process(option + length)) {
-        Log::PrintErr("Invalid option specification : '%s'\n", option);
+      if (main_options[i].process(option + length)) {
+        return true;
       }
-      return true;
     }
     i += 1;
     name = main_options[i].option_name;
   }
   return false;
 }
 
 
 // Convert all the arguments to UTF8. On Windows, the arguments are
 // encoded in the current code page and not UTF8.
@@ skipping 594 matching lines @@
 
   return Process::GlobalExitCode();
 }
 
 }  // namespace bin
 }  // namespace dart
 
 int main(int argc, char** argv) {
   return dart::bin::main(argc, argv);
 }