Correctly stringify mixed encoding indirect strings.

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 310d93c04ea8b9cadda0c1cbad1d3e25658b923f..f9d8fe630509c9944e7c5a4734cc002fce46f6b5 100644
--- a/test/cctest/test-strings.cc
+++ b/test/cctest/test-strings.cc
@@ -1017,6 +1017,64 @@ TEST(ExternalShortStringAdd) {
 }
 
 
+TEST(JSONStringifySliceMadeExternal) {
+  Isolate* isolate = Isolate::Current();
+  Zone zone(isolate);
+  CcTest::InitializeVM();
+
+  // Create a sliced string from a two-byte string.  The latter is turned
+  // into a one-byte external string.  Check that JSON.stringify works.
+  { v8::HandleScope handle_scope(CcTest::isolate());
+    v8::Handle<v8::String> underlying =
+        CompileRun("var underlying = '\u2603bcdefghijklmnopqrstuvwxyz';"
+                   "underlying")->ToString();
+    v8::Handle<v8::String> slice =
+        CompileRun("var slice = underlying.slice(1);"
+                   "slice")->ToString();
+    CHECK(v8::Utils::OpenHandle(*slice)->IsSlicedString());
+    CHECK(v8::Utils::OpenHandle(*underlying)->IsSeqTwoByteString());
+
+    int length = underlying->Length();
+    uint8_t* one_byte = zone.NewArray<uint8_t>(length + 1);
+    underlying->WriteOneByte(one_byte);
+    AsciiResource* resource =
+        new(&zone) AsciiResource(Vector<const char>(
+            reinterpret_cast<char*>(one_byte), length));
+    CHECK(underlying->MakeExternal(resource));
+    CHECK(v8::Utils::OpenHandle(*slice)->IsSlicedString());
+    CHECK(v8::Utils::OpenHandle(*underlying)->IsExternalAsciiString());
+
+    CHECK_EQ("\"bcdefghijklmnopqrstuvwxyz\"",
+             *v8::String::Utf8Value(CompileRun("JSON.stringify(slice)")));
+  }
+
+  // Create a sliced string from a one-byte string.  The latter is turned
+  // into a two-byte external string.  Check that JSON.stringify works.
+  { v8::HandleScope handle_scope(CcTest::isolate());
+    v8::Handle<v8::String> underlying =
+        CompileRun("var underlying = 'abcdefghijklmnopqrstuvwxyz';"
+                   "underlying")->ToString();
+    v8::Handle<v8::String> slice =
+        CompileRun("var slice = underlying.slice(1);"
+                   "slice")->ToString();
+    CHECK(v8::Utils::OpenHandle(*slice)->IsSlicedString());
+    CHECK(v8::Utils::OpenHandle(*underlying)->IsSeqOneByteString());
+
+    int length = underlying->Length();
+    uc16* two_byte = zone.NewArray<uc16>(length + 1);
+    underlying->Write(two_byte);
+    Resource* resource =
+        new(&zone) Resource(Vector<const uc16>(two_byte, length));
+    CHECK(underlying->MakeExternal(resource));
+    CHECK(v8::Utils::OpenHandle(*slice)->IsSlicedString());
+    CHECK(v8::Utils::OpenHandle(*underlying)->IsExternalTwoByteString());
+
+    CHECK_EQ("\"bcdefghijklmnopqrstuvwxyz\"",
+             *v8::String::Utf8Value(CompileRun("JSON.stringify(slice)")));
+  }
+}
+
+
 TEST(CachedHashOverflow) {
   // We incorrectly allowed strings to be tagged as array indices even if their
   // values didn't fit in the hash field.