Fix another message object leak.

Review URL: http://codereview.chromium.org/6269021

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@6495 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/messages.js

@@ -82,8 +82,11 @@ function FormatString(format, args) {
   var result = format;
   for (var i = 0; i < args.length; i++) {
     var str;
-    try { str = ToDetailString(args[i]); }
-    catch (e) { str = "#<error>"; }
+    try {
+      str = ToDetailString(args[i]);
+    } catch (e) {
+      str = "#<error>";
+    }
     result = ArrayJoin.call(StringSplit.call(result, "%" + i), str);
   }
   return result;
@@ -124,7 +127,9 @@ function ToDetailString(obj) {
     var constructor = obj.constructor;
     if (!constructor) return ToStringCheckErrorObject(obj);
     var constructorName = constructor.name;
-    if (!constructorName) return ToStringCheckErrorObject(obj);
+    if (!constructorName || !IS_STRING(constructorName)) {
+      return ToStringCheckErrorObject(obj);
+    }
     return "#<" + GetInstanceName(constructorName) + ">";
   } else {
     return ToStringCheckErrorObject(obj);

test/cctest/test-api.cc

@@ -2389,6 +2389,11 @@ TEST(APIThrowMessageOverwrittenToString) {
   CompileRun("asdf;");
   v8::Handle<Value> string = CompileRun("try { asdf; } catch(e) { e + ''; }");
   CHECK(string->Equals(v8_str("Whoops")));
+  CompileRun("ReferenceError.prototype.constructor = new Object();"
+             "ReferenceError.prototype.constructor.name = 1;"
+             "Number.prototype.toString = function() { return 'Whoops'; };"
+             "ReferenceError.prototype.toString = Object.prototype.toString;");
+  CompileRun("asdf;");
   v8::V8::RemoveMessageListeners(check_message);
 }