Default to binary encoding when loading MHTML files.

Source/core/loader/archive/MHTMLParser.cpp

 /*
  * Copyright (C) 2011 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 121 matching lines @@
 
     RefPtr<MHTMLArchive> subframe = MHTMLArchive::create();
     subframe->setMainResource(resource);
     m_frames.append(subframe);
 }
 
 PassRefPtr<ArchiveResource> MHTMLParser::parseNextPart(const MIMEHeader& mimeHeader, const String& endOfPartBoundary, const String& endOfDocumentBoundary, bool& endOfArchiveReached)
 {
     ASSERT(endOfPartBoundary.isEmpty() == endOfDocumentBoundary.isEmpty());
 
+    // If no content transfer encoding is specified, default to binary encoding.
+    MIMEHeader::Encoding contentTransferEncoding = mimeHeader.contentTransferEncoding();
+    if (contentTransferEncoding == MIMEHeader::Unknown)
+        contentTransferEncoding = MIMEHeader::Binary;
+
     RefPtr<SharedBuffer> content = SharedBuffer::create();
     const bool checkBoundary = !endOfPartBoundary.isEmpty();
     bool endOfPartReached = false;
-    if (mimeHeader.contentTransferEncoding() == MIMEHeader::Binary) {
+    if (contentTransferEncoding == MIMEHeader::Binary) {
         if (!checkBoundary) {
             LOG_ERROR("Binary contents requires end of part");
             return 0;
         }
         m_lineReader.setSeparator(endOfPartBoundary.utf8().data());
         Vector<char> part;
         if (!m_lineReader.nextChunk(part)) {
             LOG_ERROR("Binary contents requires end of part");
             return 0;
          }
@@ skipping 17 matching lines @@
     } else {
         String line;
         while (!(line = m_lineReader.nextChunkAsUTF8StringWithLatin1Fallback()).isNull()) {
             endOfArchiveReached = (line == endOfDocumentBoundary);
             if (checkBoundary && (line == endOfPartBoundary || endOfArchiveReached)) {
                 endOfPartReached = true;
                 break;
             }
             // Note that we use line.utf8() and not line.ascii() as ascii turns special characters (such as tab, line-feed...) into '?'.
             content->append(line.utf8().data(), line.length());
-            if (mimeHeader.contentTransferEncoding() == MIMEHeader::QuotedPrintable) {
+            if (contentTransferEncoding == MIMEHeader::QuotedPrintable) {
                 // The line reader removes the \r\n, but we need them for the content in this case as the QuotedPrintable decoder expects CR-LF terminated lines.
                 content->append("\r\n", 2);
             }
         }
     }
     if (!endOfPartReached && checkBoundary) {
         LOG_ERROR("No bounday found for MHTML part.");
         return 0;
     }
 
     Vector<char> data;
-    switch (mimeHeader.contentTransferEncoding()) {
+    switch (contentTransferEncoding) {
     case MIMEHeader::Base64:
         if (!base64Decode(content->data(), content->size(), data)) {
             LOG_ERROR("Invalid base64 content for MHTML part.");
             return 0;
         }
         break;
     case MIMEHeader::QuotedPrintable:
         quotedPrintableDecode(content->data(), content->size(), data);
         break;
     case MIMEHeader::EightBit:
@@ skipping 27 matching lines @@
 {
     return m_resources.size();
 }
 
 ArchiveResource* MHTMLParser::subResourceAt(size_t index) const
 {
     return m_resources[index].get();
 }
 
 }