Introduce String::fromUTF8Lenient() and use it for cache_name in CacheStorage API.

third_party/WebKit/Source/wtf/text/WTFStringTest.cpp

Index: third_party/WebKit/Source/wtf/text/WTFStringTest.cpp
diff --git a/third_party/WebKit/Source/wtf/text/WTFStringTest.cpp b/third_party/WebKit/Source/wtf/text/WTFStringTest.cpp
index 319320f0341fb6e9908cd03ea3596f5b4b007c87..12c2d4b7d4165fbe9da8db8aad5912830906e692 100644
--- a/third_party/WebKit/Source/wtf/text/WTFStringTest.cpp
+++ b/third_party/WebKit/Source/wtf/text/WTFStringTest.cpp
@@ -66,6 +66,35 @@ void testNumberToStringECMAScript(double number, const char* reference)
     EXPECT_STREQ(reference, numberString.data());
 }
 
+void testRoundTripConvertSuccess(const UChar* characters, unsigned length)
+{
+    String utf16String(characters, length);
+    EXPECT_FALSE(utf16String.isNull());
+    std::string utf8String(utf16String.utf8().data(), utf16String.utf8().length());
+    String utf16NewString = String::fromUTF8(utf8String.data(), utf8String.length());
+    EXPECT_FALSE(utf16NewString.isNull());
+    EXPECT_TRUE(utf16String == utf16NewString);
+}
+
+void testRoundTripConvertFailure(const UChar* characters, unsigned length)
+{
+    String utf16String(characters, length);
+    EXPECT_FALSE(utf16String.isNull());
+    std::string utf8String(utf16String.utf8().data(), utf16String.utf8().length());
+    String utf16NewString = String::fromUTF8(utf8String.data(), utf8String.length());
+    EXPECT_TRUE(utf16NewString.isNull());
+}
+
+void testRoundTripLenientConvert(const UChar* characters, unsigned length)
+{
+    String utf16String(characters, length);
+    EXPECT_FALSE(utf16String.isNull());
+    std::string utf8String(utf16String.utf8().data(), utf16String.utf8().length());
+    String utf16NewString = String::fromUTF8Lenient(utf8String.data(), utf8String.length());
+    EXPECT_FALSE(utf16NewString.isNull());
+    EXPECT_TRUE(utf16String == utf16NewString);
+}
+
 } // anonymous namespace
 
 TEST(StringTest, NumberToStringECMAScriptBoundaries)
@@ -401,4 +430,48 @@ TEST(StringTest, Lower)
     EXPECT_STREQ("link", String::fromUTF8("LIN\xE2\x84\xAA").lower().utf8().data());
 }
 
+TEST(StringTest, RoundTripConvert)
+{
+    for (UChar uchar = 0; uchar <= 0xD7FF; ++uchar)
+        testRoundTripConvertSuccess(&uchar, 1);
+    // String::fromUTF8() can't convert unpaired surrogates.
+    for (UChar uchar = 0xD800; uchar <= 0xDFFF; ++uchar)
+        testRoundTripConvertFailure(&uchar, 1);
+    for (UChar uchar = 0xE000; uchar != 0; ++uchar)
+        testRoundTripConvertSuccess(&uchar, 1);
+
+    // String::fromUTF8() can't convert word-swapped surrogates.
+    const UChar wordSwappedSurrogate[] = { 0xDC00, 0xD800 };
+    testRoundTripConvertFailure(wordSwappedSurrogate, 2);
+
+    // A correct surrogate pair.
+    const UChar correctSurrogatePair[] = { 0xD83D, 0xDCA9 };
+    testRoundTripConvertSuccess(correctSurrogatePair, 2);
+}
+
+TEST(StringTest, RoundTripLenientConvert)
+{
+    // String::fromUTF8Lenient() can convert all.
+    UChar uchar = 0;
+    do {
+        testRoundTripLenientConvert(&uchar, 1);
+    } while (++uchar);
+
+    // All characters in one string.
+    UChar buffer[0x10000];
+    uchar = 0;
+    do {
+        buffer[uchar] = uchar;
+    } while (++uchar);
+    testRoundTripLenientConvert(buffer, 0x10000);
+
+    // Word-swapped surrogates.
+    const UChar wordSwappedSurrogate[] = { 0xDC00, 0xD800 };
+    testRoundTripLenientConvert(wordSwappedSurrogate, 2);
+
+    // A correct surrogate pair.
+    const UChar correctSurrogatePair[] = { 0xD83D, 0xDCA9 };
+    testRoundTripLenientConvert(correctSurrogatePair, 2);
+}
+
 } // namespace WTF