Merge 73112 - 2010-12-02 Adam Barth <abarth@webkit.org>...

WebCore/platform/image-decoders/jpeg/JPEGImageDecoder.cpp

 /*
  * Copyright (C) 2006 Apple Computer, Inc.
  *
  * Portions are Copyright (C) 2001-6 mozilla.org
  *
  * Other contributors:
  *   Stuart Parmenter <stuart@mozilla.com>
  *
  * Copyright (C) 2007-2009 Torch Mobile, Inc.
  *
@@ skipping 190 matching lines @@
 
         switch (m_state) {
         case JPEG_HEADER:
             // Read file parameters with jpeg_read_header().
             if (jpeg_read_header(&m_info, true) == JPEG_SUSPENDED)
                 return false; // I/O suspension.
 
             // Let libjpeg take care of gray->RGB and YCbCr->RGB conversions.
             switch (m_info.jpeg_color_space) {
             case JCS_GRAYSCALE:
+            case JCS_YCbCr:
+                // Grayscale images get "upsampled" by libjpeg.  If we use
+                // their color profile, CoreGraphics will "upsample" them
+                // again, resulting in horizontal distortions.
+                m_decoder->setIgnoreGammaAndColorProfile(true);
+                // Note fall-through!
             case JCS_RGB:
-            case JCS_YCbCr:
                 m_info.out_color_space = JCS_RGB;
                 break;
             case JCS_CMYK:
             case JCS_YCCK:
                 // jpeglib cannot convert these to rgb, but it can convert ycck
                 // to cmyk.
                 m_info.out_color_space = JCS_CMYK;
                 break;
             default:
                 return m_decoder->setFailed();
@@ skipping 299 matching lines @@
     // has failed.
     if (!m_reader->decode(m_data->buffer(), onlySize) && isAllDataReceived())
         setFailed();
     // If we're done decoding the image, we don't need the JPEGImageReader
     // anymore.  (If we failed, |m_reader| has already been cleared.)
     else if (!m_frameBufferCache.isEmpty() && (m_frameBufferCache[0].status() == RGBA32Buffer::FrameComplete))
         m_reader.clear();
 }
 
 }