diff -r 000000000000 -r 6474c204b198 image/decoders/icon/qt/nsIconChannel.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/image/decoders/icon/qt/nsIconChannel.cpp	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,119 @@
+/* vim:set ts=2 sw=2 sts=2 cin et: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include <QIcon>
+
+#include <stdlib.h>
+#include <unistd.h>
+
+#include "mozilla/Endian.h"
+
+#include "nsMimeTypes.h"
+#include "nsIMIMEService.h"
+
+#include "nsIStringBundle.h"
+
+#include "nsNetUtil.h"
+#include "nsIURL.h"
+
+#include "nsIconChannel.h"
+#include "nsGtkQtIconsConverter.h"
+
+NS_IMPL_ISUPPORTS(nsIconChannel,
+                  nsIRequest,
+                  nsIChannel)
+
+static nsresult
+moz_qicon_to_channel(QImage *image, nsIURI *aURI,
+                     nsIChannel **aChannel)
+{
+  NS_ENSURE_ARG_POINTER(image);
+
+  int width = image->width();
+  int height = image->height();
+
+  NS_ENSURE_TRUE(height < 256 && width < 256 && height > 0 && width > 0,
+                 NS_ERROR_UNEXPECTED);
+
+  const int n_channels = 4;
+  long int buf_size = 2 + n_channels * height * width;
+  uint8_t * const buf = (uint8_t*)NS_Alloc(buf_size);
+  NS_ENSURE_TRUE(buf, NS_ERROR_OUT_OF_MEMORY);
+  uint8_t *out = buf;
+
+  *(out++) = width;
+  *(out++) = height;
+
+  const uchar * const pixels = image->bits();
+  int rowextra = image->bytesPerLine() - width * n_channels;
+
+  // encode the RGB data and the A data
+  const uchar * in = pixels;
+  for (int y = 0; y < height; ++y, in += rowextra) {
+    for (int x = 0; x < width; ++x) {
+      uint8_t r = *(in++);
+      uint8_t g = *(in++);
+      uint8_t b = *(in++);
+      uint8_t a = *(in++);
+#define DO_PREMULTIPLY(c_) uint8_t(uint16_t(c_) * uint16_t(a) / uint16_t(255))
+#if MOZ_LITTLE_ENDIAN
+      *(out++) = DO_PREMULTIPLY(b);
+      *(out++) = DO_PREMULTIPLY(g);
+      *(out++) = DO_PREMULTIPLY(r);
+      *(out++) = a;
+#else
+      *(out++) = a;
+      *(out++) = DO_PREMULTIPLY(r);
+      *(out++) = DO_PREMULTIPLY(g);
+      *(out++) = DO_PREMULTIPLY(b);
+#endif
+#undef DO_PREMULTIPLY
+    }
+  }
+
+  NS_ASSERTION(out == buf + buf_size, "size miscalculation");
+
+  nsresult rv;
+  nsCOMPtr<nsIStringInputStream> stream =
+    do_CreateInstance("@mozilla.org/io/string-input-stream;1", &rv);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  rv = stream->AdoptData((char*)buf, buf_size);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  return NS_NewInputStreamChannel(aChannel, aURI, stream,
+                                  NS_LITERAL_CSTRING(IMAGE_ICON_MS));
+}
+
+nsresult
+nsIconChannel::Init(nsIURI* aURI)
+{
+
+  nsCOMPtr<nsIMozIconURI> iconURI = do_QueryInterface(aURI);
+  NS_ASSERTION(iconURI, "URI is not an nsIMozIconURI");
+
+  nsAutoCString stockIcon;
+  iconURI->GetStockIcon(stockIcon);
+
+  nsAutoCString iconSizeString;
+  iconURI->GetIconSize(iconSizeString);
+
+  uint32_t desiredImageSize;
+  iconURI->GetImageSize(&desiredImageSize);
+
+  nsAutoCString iconStateString;
+  iconURI->GetIconState(iconStateString);
+  bool disabled = iconStateString.EqualsLiteral("disabled");
+
+  // This is a workaround for https://bugzilla.mozilla.org/show_bug.cgi?id=662299
+  // Try to find corresponding freedesktop icon and fallback to empty QIcon if failed.
+  QIcon icon = QIcon::fromTheme(QString(stockIcon.get()).replace("gtk-", "edit-"));
+  QPixmap pixmap = icon.pixmap(desiredImageSize, desiredImageSize, disabled ? QIcon::Disabled : QIcon::Normal);
+
+  QImage image = pixmap.toImage();
+
+  return moz_qicon_to_channel(&image, iconURI,
+                              getter_AddRefs(mRealChannel));
+}