Improve indexOf for one byte string receiver to work with other string classes.

runtime/vm/dart_api_impl_test.cc

 // Copyright (c) 2012, 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 "bin/builtin.h"
 #include "include/dart_api.h"
 #include "include/dart_debugger_api.h"
 #include "include/dart_mirrors_api.h"
 #include "include/dart_native_api.h"
 #include "platform/assert.h"
@@ skipping 7244 matching lines @@
   EXPECT_VALID(Dart_StringStorageSize(str_arg, &arg_size));
   EXPECT_EQ(size, arg_size);
   char* str_data = new char[size];
   Dart_Handle result =
       Dart_MakeExternalString(str,
                               str_data,
                               size,
                               str_data,
                               &ExternalStringDeoptimize_Finalize);
   EXPECT_VALID(result);
+  EXPECT(Dart_IsExternalString(result));
   Dart_ExitScope();
 }
 
 
 static Dart_NativeFunction ExternalStringDeoptimize_native_lookup(
     Dart_Handle name, int argument_count) {
   return reinterpret_cast<Dart_NativeFunction>(&A_change_str_native);
 }
 
 
@@ skipping 123 matching lines @@
   Dart_Handle result = Dart_Invoke(lib,
                                    NewString("main"),
                                    0,
                                    NULL);
   int64_t value = 0;
   result = Dart_IntegerToInt64(result, &value);
   EXPECT_VALID(result);
   EXPECT_EQ(8, value);
 }
 
+
+TEST_CASE(ExternalStringIndexOf) {
+    const char* kScriptChars =
+      "main(String pattern) {\n"
+      "  var str = 'Hello World';\n"
+      "  return str.indexOf(pattern);\n"
+      "}\n";
+  Dart_Handle lib =
+      TestCase::LoadTestScript(kScriptChars, NULL);
+
+  uint8_t data8[] = { 'W' };
+  Dart_Handle ext8 = Dart_NewExternalLatin1String(data8, ARRAY_SIZE(data8),
+                                                  data8, NULL);
+  EXPECT_VALID(ext8);
+  EXPECT(Dart_IsString(ext8));
+  EXPECT(Dart_IsExternalString(ext8));
+
+  Dart_Handle dart_args[1];
+  dart_args[0] = ext8;
+  Dart_Handle result = Dart_Invoke(lib,
+                                   NewString("main"),
+                                   1,
+                                   dart_args);
+  int64_t value = 0;
+  result = Dart_IntegerToInt64(result, &value);
+  EXPECT_VALID(result);
+  EXPECT_EQ(6, value);
+}
+
 }  // namespace dart