Internalize strings in-place

test/cctest/test-strings.cc

Index: test/cctest/test-strings.cc
diff --git a/test/cctest/test-strings.cc b/test/cctest/test-strings.cc
index d7b51f8274cbaf35058f14ad7ebb38ac2866d1fb..ff3b7bddaa094edf0e5b68ad15a420378838b74f 100644
--- a/test/cctest/test-strings.cc
+++ b/test/cctest/test-strings.cc
@@ -1195,6 +1195,31 @@ class OneByteVectorResource : public v8::String::ExternalOneByteStringResource {
   i::Vector<const char> data_;
 };
 
+TEST(InternalizeExternal) {
+  i::Isolate* isolate = CcTest::i_isolate();
+  Factory* factory = isolate->factory();
+  // This won't leak; the external string mechanism will call Dispose() on it.
+  OneByteVectorResource* resource =
+      new OneByteVectorResource(i::Vector<const char>("prop", 4));
+  {
+    v8::HandleScope scope(CcTest::isolate());
+    v8::Local<v8::String> ext_string =
+        v8::String::NewExternalOneByte(CcTest::isolate(), resource)
+            .ToLocalChecked();
+    Handle<String> string = v8::Utils::OpenHandle(*ext_string);
+    CHECK(string->IsExternalString());
+    CHECK(!string->IsInternalizedString());
+    CHECK(isolate->heap()->InNewSpace(*string));
+    factory->InternalizeName(string);
+    CHECK(string->IsThinString());
+    CcTest::CollectGarbage(i::NEW_SPACE);
+    CcTest::CollectGarbage(i::NEW_SPACE);
+    CHECK(string->IsInternalizedString());
+    CHECK(!isolate->heap()->InNewSpace(*string));
+  }
+  CcTest::CollectGarbage(i::OLD_SPACE);
+  CcTest::CollectGarbage(i::OLD_SPACE);
+}
 
 TEST(SliceFromExternal) {
   FLAG_string_slices = true;