Fix BOM handling in TextResourceDecoder on partial data

third_party/WebKit/Source/core/html/parser/TextResourceDecoderTest.cpp

+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "core/html/parser/TextResourceDecoder.h"
+
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace blink {
+
+namespace {
+
+const char kUTF16TextMimeType[] = "text/plain; charset=utf-16";
+
+} // namespace
+
+TEST(TextResourceDecoderTest, BasicUTF16)
+{
+    std::unique_ptr<TextResourceDecoder> decoder = TextResourceDecoder::create(kUTF16TextMimeType);
+    WTF::String decoded;
+
+    const unsigned char fooLE[] = {0xff, 0xfe, 0x66, 0x00, 0x6f, 0x00, 0x6f, 0x00};
+    decoded = decoder->decode(reinterpret_cast<const char*>(fooLE), sizeof(fooLE));
+    decoded = decoded + decoder->flush();
+    EXPECT_EQ("foo", decoded);
+
+    decoder = TextResourceDecoder::create(kUTF16TextMimeType);
+    const unsigned char fooBE[] = {0xfe, 0xff, 0x00, 0x66, 0x00, 0x6f, 0x00, 0x6f};
+    decoded = decoder->decode(reinterpret_cast<const char*>(fooBE), sizeof(fooBE));
+    decoded = decoded + decoder->flush();
+    EXPECT_EQ("foo", decoded);
+}
+
+TEST(TextResourceDecoderTest, UTF16Pieces)
+{
+    std::unique_ptr<TextResourceDecoder> decoder = TextResourceDecoder::create(kUTF16TextMimeType);
+
+    WTF::String decoded;
+    const unsigned char foo[] = {0xff, 0xfe, 0x66, 0x00, 0x6f, 0x00, 0x6f, 0x00};
+    for (char c : foo)
+        decoded = decoded + decoder->decode(reinterpret_cast<const char*>(&c), 1);
+    decoded = decoded + decoder->flush();
+    EXPECT_EQ("foo", decoded);
+}
+
+} // namespace blink