Fix for bug 1229: Unary operator plus is not allowed ... except for literals.

runtime/lib/math.cc

 // Copyright (c) 2011, 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 <ctype.h>  // isspace.
 
 #include "vm/bootstrap_natives.h"
 
 #include "vm/bigint_operations.h"
 #include "vm/exceptions.h"
@@ skipping 71 matching lines @@
                            bool* is_positive,
                            String** value) {
   if ((tokens.length() == 2) &&
       (tokens[0].kind == literal_kind) &&
       (tokens[1].kind == Token::kEOS)) {
     *is_positive = true;
     *value = tokens[0].literal;
     return true;
   }
   if ((tokens.length() == 3) &&
-      ((tokens[0].kind == Token::kADD) || (tokens[0].kind == Token::kSUB)) &&
+      ((tokens[0].kind == Token::kTIGHTADD) ||
+          (tokens[0].kind == Token::kSUB)) &&
       (tokens[1].kind == literal_kind) &&
       (tokens[2].kind == Token::kEOS)) {
     // Check there is no space between "+/-" and number.
     if ((tokens[0].offset + 1) != tokens[1].offset) {
       return false;
     }
-    *is_positive = tokens[0].kind == Token::kADD;
+    *is_positive = tokens[0].kind == Token::kTIGHTADD;
     *value = tokens[1].literal;
     return true;
   }
   return false;
 }
 
 
 DEFINE_NATIVE_ENTRY(MathNatives_parseInt, 1) {
   GET_NATIVE_ARGUMENT(String, value, arguments->At(0));
   Scanner scanner(value, String::Handle());
@@ skipping 63 matching lines @@
       return;
     }
   }
 
   GrowableArray<const Object*> args;
   args.Add(&value);
   Exceptions::ThrowByType(Exceptions::kBadNumberFormat, args);
 }
 
 }  // namespace dart