Do not normalize into NFC the values of form fields

Source/wtf/text/TextEncoding.cpp

Index: Source/wtf/text/TextEncoding.cpp
diff --git a/Source/wtf/text/TextEncoding.cpp b/Source/wtf/text/TextEncoding.cpp
index 90a31d487f99ff88e57b3ff08605d7a6e8429242..b2e8807e357181590c34589fbb851aca397494b4 100644
--- a/Source/wtf/text/TextEncoding.cpp
+++ b/Source/wtf/text/TextEncoding.cpp
@@ -66,6 +66,11 @@ String TextEncoding::decode(const char* data, size_t length, bool stopOnError, b
 
 CString TextEncoding::encode(const String& string, UnencodableHandling handling) const
 {
+    return encode(string, NFCNormalization, handling);
+}
+
+CString TextEncoding::encode(const String& string, NormalizationMode mode, UnencodableHandling handling) const
+{
     if (!m_name)
         return CString();
 
@@ -76,27 +81,35 @@ CString TextEncoding::encode(const String& string, UnencodableHandling handling)
     // unaffected by NFC. This is effectively the same as saying that all
     // Latin-1 text is already normalized to NFC.
     // Source: http://unicode.org/reports/tr15/
-    if (string.is8Bit())
+    if ((mode == NoNormalization || mode == NFCNormalization)
+        && string.is8Bit())
         return newTextCodec(*this)->encode(string.characters8(), string.length(), handling);
 
-    // FIXME: What's the right place to do normalization?
-    // It's a little strange to do it inside the encode function.
-    // Perhaps normalization should be an explicit step done before calling encode.
-
     const UChar* source = string.characters16();
     size_t length = string.length();
 
     Vector<UChar> normalizedCharacters;
 
+    UNormalizationMode unormMode;
+    switch (mode) {
+    case NoNormalization:
+        unormMode = UNORM_NONE;
+        break;
+    case NFCNormalization:
+        unormMode = UNORM_NFC;
+        break;
+    }
+
     UErrorCode err = U_ZERO_ERROR;
-    if (unorm_quickCheck(source, length, UNORM_NFC, &err) != UNORM_YES) {
-        // First try using the length of the original string, since normalization to NFC rarely increases length.
+    if (mode != NoNormalization
+        && unorm_quickCheck(source, length, unormMode, &err) != UNORM_YES) {
+        // First try using the length of the original string, since normalization might not increase the length.
         normalizedCharacters.grow(length);
-        int32_t normalizedLength = unorm_normalize(source, length, UNORM_NFC, 0, normalizedCharacters.data(), length, &err);
+        int32_t normalizedLength = unorm_normalize(source, length, unormMode, 0, normalizedCharacters.data(), length, &err);
         if (err == U_BUFFER_OVERFLOW_ERROR) {
             err = U_ZERO_ERROR;
             normalizedCharacters.resize(normalizedLength);
-            normalizedLength = unorm_normalize(source, length, UNORM_NFC, 0, normalizedCharacters.data(), normalizedLength, &err);
+            normalizedLength = unorm_normalize(source, length, unormMode, 0, normalizedCharacters.data(), normalizedLength, &err);
         }
         ASSERT(U_SUCCESS(err));