Avoid redundant allocation of accessor names.

runtime/vm/object_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 "platform/globals.h"
 
 #include "vm/assembler.h"
 #include "vm/bigint_operations.h"
 #include "vm/class_finalizer.h"
 #include "vm/dart_api_impl.h"
@@ skipping 1318 matching lines @@
     EXPECT_EQ(twostr.Length()*2 + onestr.Length(), two_one_two_str.Length());
     uint16_t two_one_two[] = { 0x05E6, 0x05D5, 0x05D5, 0x05D9, 0x05D9,
                                'o', 'n', 'e', ' ', 'b', 'y', 't', 'e',
                                0x05E6, 0x05D5, 0x05D5, 0x05D9, 0x05D9 };
     intptr_t two_one_two_len = sizeof(two_one_two) / sizeof(two_one_two[0]);
     EXPECT(two_one_two_str.Equals(two_one_two, two_one_two_len));
   }
 }
 
 
+TEST_CASE(StringHashConcat) {
+  EXPECT_EQ(String::Handle(String::New("onebyte")).Hash(),
+            String::HashConcat(String::Handle(String::New("one")),
+                               String::Handle(String::New("byte"))));
+  uint16_t clef_utf16[] = { 0xD834, 0xDD1E };
+  const String& clef = String::Handle(String::FromUTF16(clef_utf16, 2));
+  int32_t clef_utf32[] = { 0x1D11E };
+  EXPECT(clef.Equals(clef_utf32, 1));
+  intptr_t hash32 = String::Hash(clef_utf32, 1);
+  EXPECT_EQ(hash32, clef.Hash());
+  EXPECT_EQ(hash32, String::HashConcat(
+      String::Handle(String::FromUTF16(clef_utf16, 1)),
+      String::Handle(String::FromUTF16(clef_utf16 + 1, 1))));
+}
+
+
 TEST_CASE(StringSubStringDifferentWidth) {
   // Create 1-byte substring from a 1-byte source string.
   const char* onechars =
       "\xC3\xB6\xC3\xB1\xC3\xA9";
 
   const String& onestr = String::Handle(String::New(onechars));
   EXPECT(!onestr.IsNull());
   EXPECT(onestr.IsOneByteString());
   EXPECT(!onestr.IsTwoByteString());
 
@@ skipping 2850 matching lines @@
   EXPECT_VALID(h_result);
   Integer& result = Integer::Handle();
   result ^= Api::UnwrapHandle(h_result);
   String& foo = String::Handle(String::New("foo"));
   Integer& expected = Integer::Handle();
   expected ^= foo.HashCode();
   EXPECT(result.IsIdenticalTo(expected));
 }
 
 }  // namespace dart