Ignore 7-bit encodings

third_party/WebKit/Source/platform/text/TextEncodingDetector.cpp

 /*
  * Copyright (C) 2008, 2009 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 28 matching lines @@
     const char* hintEncodingName, WTF::TextEncoding* detectedEncoding)
 {
     *detectedEncoding = WTF::TextEncoding();
     int consumedBytes;
     bool isReliable;
     Encoding encoding = CompactEncDet::DetectEncoding(
         data, length, nullptr, nullptr, nullptr,
         EncodingNameAliasToEncoding(hintEncodingName),
         UNKNOWN_LANGUAGE,
         CompactEncDet::WEB_CORPUS,
-        false, // Include 7-bit encodings
+        false, // Include 7-bit encodings to detect ISO-2022-JP
         &consumedBytes,
         &isReliable);
-    if (encoding != UNKNOWN_ENCODING) {
-        *detectedEncoding = WTF::TextEncoding(MimeEncodingName(encoding));
-        return true;
+    if (encoding == UNKNOWN_ENCODING)
+        return false;
+
+    // 7-bit encodings (except ISO-2022-JP) are not supported in WHATWG encoding
+    // standard. Mark them as ASCII to keep the raw bytes intact.
+    switch (encoding) {
+    case HZ_GB_2312:
+    case ISO_2022_KR:
+    case ISO_2022_CN:
+    case UTF7:
+        encoding = ASCII_7BIT;
+        break;
+    default:
+        break;
     }
-    return false;
+    *detectedEncoding = WTF::TextEncoding(MimeEncodingName(encoding));
+    return true;
 }
 
 } // namespace blink