String::NewExternal should not crash the renderer.

test/cctest/test-api.cc

Index: test/cctest/test-api.cc
diff --git a/test/cctest/test-api.cc b/test/cctest/test-api.cc
index 8fd87434c1b27aaeb5c31ce8af06026aa834cc62..b4cf5cf4a9891e7442ac307a71b34bc761ac5927 100644
--- a/test/cctest/test-api.cc
+++ b/test/cctest/test-api.cc
@@ -742,6 +742,53 @@ THREADED_TEST(UsingExternalOneByteString) {
 }
 
 
+class DummyResource : public v8::String::ExternalStringResource {
+ public:
+  virtual const uint16_t* data() const { return string_; }
+  virtual size_t length() const { return 1 << 30; }
+
+ private:
+  uint16_t string_[10];
+};
+
+
+class DummyOneByteResource : public v8::String::ExternalOneByteStringResource {
+ public:
+  virtual const char* data() const { return string_; }
+  virtual size_t length() const { return 1 << 30; }
+
+ private:
+  char string_[10];
+};
+
+
+THREADED_TEST(NewExternalForVeryLongString) {
+  {
+    LocalContext env;
+    v8::HandleScope scope(env->GetIsolate());
+    v8::TryCatch try_catch;
+    DummyOneByteResource r;
+    v8::Local<v8::String> str = v8::String::NewExternal(CcTest::isolate(), &r);
+    CHECK(str.IsEmpty());
+    CHECK(try_catch.HasCaught());
+    String::Utf8Value exception_value(try_catch.Exception());
+    CHECK_EQ("RangeError: Invalid string length", *exception_value);
+  }
+
+  {
+    LocalContext env;
+    v8::HandleScope scope(env->GetIsolate());
+    v8::TryCatch try_catch;
+    DummyResource r;
+    v8::Local<v8::String> str = v8::String::NewExternal(CcTest::isolate(), &r);
+    CHECK(str.IsEmpty());
+    CHECK(try_catch.HasCaught());
+    String::Utf8Value exception_value(try_catch.Exception());
+    CHECK_EQ("RangeError: Invalid string length", *exception_value);
+  }
+}
+
+
 THREADED_TEST(ScavengeExternalString) {
   i::FLAG_stress_compaction = false;
   i::FLAG_gc_global = false;