--- a/image/decoders/nsBMPDecoder.cpp
+++ b/image/decoders/nsBMPDecoder.cpp
@@ -273,17 +273,18 @@ nsBMPDecoder::WriteInternal(const char* 
             return;
         }
 
         PRUint32 real_height = (mBIH.height > 0) ? mBIH.height : -mBIH.height;
 
         // Post our size to the superclass
         PostSize(mBIH.width, real_height);
         if (HasError()) {
-          // Setting the size led to an error.
+          // Setting the size lead to an error; this can happen when for example
+          // a multipart channel sends an image of a different size.
           return;
         }
 
         // We have the size. If we're doing a size decode, we got what
         // we came for.
         if (IsSizeDecode())
             return;
 

--- a/image/decoders/nsGIFDecoder2.cpp
+++ b/image/decoders/nsGIFDecoder2.cpp
@@ -915,17 +915,18 @@ nsGIFDecoder2::WriteInternal(const char 
           mGIFStruct.screen_height = mGIFStruct.height;
           mGIFStruct.screen_width = mGIFStruct.width;
           mGIFStruct.x_offset = 0;
           mGIFStruct.y_offset = 0;
         }    
         // Create the image container with the right size.
         BeginGIF();
         if (HasError()) {
-          // Setting the size led to an error.
+          // Setting the size lead to an error; this can happen when for example
+          // a multipart channel sends an image of a different size.
           mGIFStruct.state = gif_error;
           return;
         }
 
         // If we were doing a size decode, we're done
         if (IsSizeDecode())
           return;
       }

--- a/image/decoders/nsIconDecoder.cpp
+++ b/image/decoders/nsIconDecoder.cpp
@@ -96,17 +96,18 @@ nsIconDecoder::WriteInternal(const char 
       case iconStateHaveHeight:
 
         // Grab the Height
         mHeight = (PRUint8)*aBuffer;
 
         // Post our size to the superclass
         PostSize(mWidth, mHeight);
         if (HasError()) {
-          // Setting the size led to an error.
+          // Setting the size lead to an error; this can happen when for example
+          // a multipart channel sends an image of a different size.
           mState = iconStateFinished;
           return;
         }
 
         // If We're doing a size decode, we're done
         if (IsSizeDecode()) {
           mState = iconStateFinished;
           break;

--- a/image/decoders/nsJPEGDecoder.cpp
+++ b/image/decoders/nsJPEGDecoder.cpp
@@ -258,17 +258,18 @@ nsJPEGDecoder::WriteInternal(const char 
       PR_LOG(gJPEGDecoderAccountingLog, PR_LOG_DEBUG,
              ("} (JPEG_SUSPENDED)"));
       return; /* I/O suspension */
     }
 
     // Post our size to the superclass
     PostSize(mInfo.image_width, mInfo.image_height);
     if (HasError()) {
-      // Setting the size led to an error.
+      // Setting the size lead to an error; this can happen when for example
+      // a multipart channel sends an image of a different size.
       mState = JPEG_ERROR;
       return;
     }
 
     /* If we're doing a size decode, we're done. */
     if (IsSizeDecode())
       return;
 

--- a/image/decoders/nsPNGDecoder.cpp
+++ b/image/decoders/nsPNGDecoder.cpp
@@ -514,17 +514,18 @@ nsPNGDecoder::info_callback(png_structp 
 
   /* Are we too big? */
   if (width > MOZ_PNG_MAX_DIMENSION || height > MOZ_PNG_MAX_DIMENSION)
     longjmp(png_jmpbuf(decoder->mPNG), 1);
 
   // Post our size to the superclass
   decoder->PostSize(width, height);
   if (decoder->HasError()) {
-    // Setting the size led to an error.
+    // Setting the size lead to an error; this can happen when for example
+    // a multipart channel sends an image of a different size.
     longjmp(png_jmpbuf(decoder->mPNG), 1);
   }
 
   if (color_type == PNG_COLOR_TYPE_PALETTE)
     png_set_expand(png_ptr);
 
   if (color_type == PNG_COLOR_TYPE_GRAY && bit_depth < 8)
     png_set_expand(png_ptr);

--- a/image/public/imgIRequest.idl
+++ b/image/public/imgIRequest.idl
@@ -47,17 +47,17 @@ interface nsIPrincipal;
 
 /**
  * imgIRequest interface
  *
  * @author Stuart Parmenter <stuart@mozilla.com>
  * @version 0.1
  * @see imagelib2
  */
-[scriptable, uuid(a5a785a8-9881-11e1-aaff-001fbc092072)]
+[scriptable, uuid(d35a9adb-8328-4b64-b06f-72a165acd080)]
 interface imgIRequest : nsIRequest
 {
   /**
    * the image container...
    * @return the image object associated with the request.
    * @attention NEED DOCS
    */
   readonly attribute imgIContainer image;
@@ -128,21 +128,16 @@ interface imgIRequest : nsIRequest
   imgIRequest clone(in imgIDecoderObserver aObserver);
 
   /**
    * The principal gotten from the channel the image was loaded from.
    */
   readonly attribute nsIPrincipal imagePrincipal;
 
   /**
-   * Whether the request is multipart (ie, multipart/x-mixed-replace)
-   */
-  readonly attribute bool multipart;
-
-  /**
    * CORS modes images can be loaded with.
    *
    * By default, all images are loaded with CORS_NONE and cannot be used
    * cross-origin in context like WebGL.
    *
    * If an HTML img element has the crossorigin attribute set, the imgIRequest
    * will be validated for cross-origin usage with CORS, and, if successful,
    * will have its CORS mode set to the relevant type.

--- a/image/src/RasterImage.cpp
+++ b/image/src/RasterImage.cpp
@@ -338,17 +338,17 @@ RasterImage::AdvanceFrame(TimeStamp aTim
   // just checking for mFrames.Length() because decoders append their frames
   // before they're filled in.
   NS_ABORT_IF_FALSE(mDecoder || nextFrameIndex <= mFrames.Length(),
                     "How did we get 2 indices too far by incrementing?");
 
   // If we don't have a decoder, we know we've got everything we're going to
   // get. If we do, we only display fully-downloaded frames; everything else
   // gets delayed.
-  bool haveFullNextFrame = (mMultipart && mBytesDecoded == 0) || !mDecoder ||
+  bool haveFullNextFrame = !mDecoder ||
                            nextFrameIndex < mDecoder->GetCompleteFrameCount();
 
   // If we're done decoding the next frame, go ahead and display it now and
   // reinit with the next frame's delay time.
   if (haveFullNextFrame) {
     if (mFrames.Length() == nextFrameIndex) {
       // End of Animation, unless we are looping forever
 
@@ -1131,19 +1131,24 @@ RasterImage::SetSize(PRInt32 aWidth, PRI
     return NS_ERROR_FAILURE;
 
   // Ensure that we have positive values
   // XXX - Why isn't the size unsigned? Should this be changed?
   if ((aWidth < 0) || (aHeight < 0))
     return NS_ERROR_INVALID_ARG;
 
   // if we already have a size, check the new size against the old one
-  if (!mMultipart && mHasSize &&
+  if (mHasSize &&
       ((aWidth != mSize.width) || (aHeight != mSize.height))) {
-    NS_WARNING("Image changed size on redecode! This should not happen!");
+
+    // Alter the warning depending on whether the channel is multipart
+    if (!mMultipart)
+      NS_WARNING("Image changed size on redecode! This should not happen!");
+    else
+      NS_WARNING("Multipart channel sent an image of a different size");
 
     // Make the decoder aware of the error so that it doesn't try to call
     // FinishInternal during ShutdownDecoder.
     if (mDecoder)
       mDecoder->PostResizeError();
 
     DoError();
     return NS_ERROR_UNEXPECTED;
@@ -1205,24 +1210,20 @@ RasterImage::EnsureFrame(PRUint32 aFrame
     if (*imageData && paletteData && *paletteData) {
       return NS_OK;
     }
     if (*imageData && !paletteData) {
       return NS_OK;
     }
   }
 
-  // Not reusable, so replace the frame directly.
   DeleteImgFrame(aFrameNum);
-  mFrames.RemoveElementAt(aFrameNum);
-  nsAutoPtr<imgFrame> newFrame(new imgFrame());
-  nsresult rv = newFrame->Init(aX, aY, aWidth, aHeight, aFormat, aPaletteDepth);
-  NS_ENSURE_SUCCESS(rv, rv);
-  return InternalAddFrameHelper(aFrameNum, newFrame.forget(), imageData,
-                                imageLength, paletteData, paletteLength);
+  return InternalAddFrame(aFrameNum, aX, aY, aWidth, aHeight, aFormat,
+                          aPaletteDepth, imageData, imageLength,
+                          paletteData, paletteLength);
 }
 
 nsresult
 RasterImage::EnsureFrame(PRUint32 aFramenum, PRInt32 aX, PRInt32 aY,
                          PRInt32 aWidth, PRInt32 aHeight,
                          gfxASurface::gfxImageFormat aFormat,
                          PRUint8** imageData, PRUint32* imageLength)
 {
@@ -1485,41 +1486,16 @@ RasterImage::AddSourceData(const char *a
 
   // We should not call this if we're already finished adding source data
   NS_ABORT_IF_FALSE(!mHasSourceData, "Calling AddSourceData() after calling "
                                      "sourceDataComplete()!");
 
   // This call should come straight from necko - no reentrancy allowed
   NS_ABORT_IF_FALSE(!mInDecoder, "Re-entrant call to AddSourceData!");
 
-  // Starting a new part's frames, let's clean up before we add any
-  // This needs to happen just before we start getting EnsureFrame() call(s),
-  // so that there's no gap for anything to miss us.
-  if (mBytesDecoded == 0) {
-    // Our previous state may have been animated, so let's clean up
-    bool wasAnimating = mAnimating;
-    if (mAnimating) {
-      StopAnimation();
-      mAnimating = false;
-    }
-    mAnimationFinished = false;
-    if (mAnim) {
-      delete mAnim;
-      mAnim = nsnull;
-    }
-    // If there's only one frame, this could cause flickering
-    int old_frame_count = mFrames.Length();
-    if (old_frame_count > 1) {
-      for (int i = 0; i < old_frame_count; ++i) {
-        DeleteImgFrame(i);
-      }
-      mFrames.Clear();
-    }
-  }
-
   // If we're not storing source data, write it directly to the decoder
   if (!StoringSourceData()) {
     rv = WriteToDecoder(aBuffer, aCount);
     CONTAINER_ENSURE_SUCCESS(rv);
 
     // We're not storing source data, so this data is probably coming straight
     // from the network. In this case, we want to display data as soon as we
     // get it, so we want to flush invalidations after every write.
@@ -1639,17 +1615,17 @@ RasterImage::SourceDataComplete()
   if (CanDiscard()) {
     nsresult rv = DiscardTracker::Reset(&mDiscardTrackerNode);
     CONTAINER_ENSURE_SUCCESS(rv);
   }
   return NS_OK;
 }
 
 nsresult
-RasterImage::NewSourceData(const char* aMimeType)
+RasterImage::NewSourceData()
 {
   nsresult rv;
 
   if (mError)
     return NS_ERROR_FAILURE;
 
   // The source data should be complete before calling this
   NS_ABORT_IF_FALSE(mHasSourceData,
@@ -1674,18 +1650,16 @@ RasterImage::NewSourceData(const char* a
 
   // The decoder was shut down and we didn't flag an error, so we should be decoded
   NS_ABORT_IF_FALSE(mDecoded, "Should be decoded in NewSourceData");
 
   // Reset some flags
   mDecoded = false;
   mHasSourceData = false;
 
-  mSourceDataMimeType.Assign(aMimeType);
-
   // We're decode-on-load here. Open up a new decoder just like what happens when
   // we call Init() for decode-on-load images.
   rv = InitDecoder(/* aDoSizeDecode = */ false);
   CONTAINER_ENSURE_SUCCESS(rv);
 
   return NS_OK;
 }
 

--- a/image/src/RasterImage.h
+++ b/image/src/RasterImage.h
@@ -299,17 +299,17 @@ public:
    * value. Should this just return void?
    */
   nsresult AddSourceData(const char *aBuffer, PRUint32 aCount);
 
   /* Called after the all the source data has been added with addSourceData. */
   nsresult SourceDataComplete();
 
   /* Called for multipart images when there's a new source image to add. */
-  nsresult NewSourceData(const char *aMimeType);
+  nsresult NewSourceData();
 
   /**
    * A hint of the number of bytes of source data that the image contains. If
    * called early on, this can help reduce copying and reallocations by
    * appropriately preallocating the source data buffer.
    *
    * We take this approach rather than having the source data management code do
    * something more complicated (like chunklisting) because HTTP is by far the

--- a/image/src/imgRequest.cpp
+++ b/image/src/imgRequest.cpp
@@ -763,29 +763,24 @@ NS_IMETHODIMP imgRequest::OnStartRequest
       mIsMultiPartChannel = true;
 
   // If we're not multipart, we shouldn't have an image yet
   NS_ABORT_IF_FALSE(mIsMultiPartChannel || !mImage,
                     "Already have an image for non-multipart request");
 
   // If we're multipart, and our image is initialized, fix things up for another round
   if (mIsMultiPartChannel && mImage) {
-    // Update the content type for this new part
-    nsCOMPtr<nsIChannel> partChan(do_QueryInterface(aRequest));
-    partChan->GetContentType(mContentType);
-    if (mContentType.EqualsLiteral(SVG_MIMETYPE) ||
-        mImage->GetType() == imgIContainer::TYPE_VECTOR) {
-      // mImage won't be reusable due to format change or a new SVG part
-      // Reset the tracker and forget that we have data for OnDataAvailable to
-      // treat its next call as a fresh image.
-      mStatusTracker = new imgStatusTracker(nsnull);
-      mGotData = false;
-    } else if (mImage->GetType() == imgIContainer::TYPE_RASTER) {
+    if (mImage->GetType() == imgIContainer::TYPE_RASTER) {
       // Inform the RasterImage that we have new source data
-      static_cast<RasterImage*>(mImage.get())->NewSourceData(mContentType.get());
+      static_cast<RasterImage*>(mImage.get())->NewSourceData();
+    } else {  // imageType == imgIContainer::TYPE_VECTOR
+      nsCOMPtr<nsIStreamListener> imageAsStream = do_QueryInterface(mImage);
+      NS_ABORT_IF_FALSE(imageAsStream,
+                        "SVG-typed Image failed QI to nsIStreamListener");
+      imageAsStream->OnStartRequest(aRequest, ctxt);
     }
   }
 
   /*
    * If mRequest is null here, then we need to set it so that we'll be able to
    * cancel it if our Cancel() method is called.  Note that this can only
    * happen for multipart channels.  We could simply not null out mRequest for
    * non-last parts, if GetIsLastPart() were reliable, but it's not.  See

--- a/image/src/imgRequest.h
+++ b/image/src/imgRequest.h
@@ -126,18 +126,16 @@ public:
   }
 
   // Set the cache validation information (expiry time, whether we must
   // validate, etc) on the cache entry based on the request information.
   // If this function is called multiple times, the information set earliest
   // wins.
   static void SetCacheValidation(imgCacheEntry* aEntry, nsIRequest* aRequest);
 
-  bool GetMultipart() const { return mIsMultiPartChannel; }
-
   // The CORS mode for which we loaded this image.
   PRInt32 GetCORSMode() const { return mCORSMode; }
 
   // The principal for the document that loaded this image. Used when trying to
   // validate a CORS image load.
   already_AddRefed<nsIPrincipal> GetLoadingPrincipal() const
   {
     nsCOMPtr<nsIPrincipal> principal = mLoadingPrincipal;

--- a/image/src/imgRequestProxy.cpp
+++ b/image/src/imgRequestProxy.cpp
@@ -553,27 +553,16 @@ NS_IMETHODIMP imgRequestProxy::GetImageP
   if (!mPrincipal)
     return NS_ERROR_FAILURE;
 
   NS_ADDREF(*aPrincipal = mPrincipal);
 
   return NS_OK;
 }
 
-/* readonly attribute bool multipart; */
-NS_IMETHODIMP imgRequestProxy::GetMultipart(bool *aMultipart)
-{
-  if (!mOwner)
-    return NS_ERROR_FAILURE;
-
-  *aMultipart = mOwner->GetMultipart();
-
-  return NS_OK;
-}
-
 /* readonly attribute PRInt32 CORSMode; */
 NS_IMETHODIMP imgRequestProxy::GetCORSMode(PRInt32* aCorsMode)
 {
   if (!mOwner)
     return NS_ERROR_FAILURE;
 
   *aCorsMode = mOwner->GetCORSMode();
 
@@ -701,20 +690,16 @@ void imgRequestProxy::OnStopContainer(im
 {
   LOG_FUNC(gImgLog, "imgRequestProxy::OnStopContainer");
 
   if (mListener && !mCanceled) {
     // Hold a ref to the listener while we call it, just in case.
     nsCOMPtr<imgIDecoderObserver> kungFuDeathGrip(mListener);
     mListener->OnStopContainer(this, image);
   }
-
-  // Multipart needs reset for next OnStartContainer
-  if (mOwner && mOwner->GetMultipart())
-    mSentStartContainer = false;
 }
 
 void imgRequestProxy::OnStopDecode(nsresult status, const PRUnichar *statusArg)
 {
   LOG_FUNC(gImgLog, "imgRequestProxy::OnStopDecode");
 
   if (mListener && !mCanceled) {
     // Hold a ref to the listener while we call it, just in case.

--- a/image/src/imgRequestProxy.h
+++ b/image/src/imgRequestProxy.h
@@ -248,13 +248,13 @@ private:
   bool mListenerIsStrongRef;
   bool mDecodeRequested;
 
   // Whether we want to defer our notifications by the non-virtual Observer
   // interfaces as image loads proceed.
   bool mDeferNotifications;
 
   // We only want to send OnStartContainer once for each proxy, but we might
-  // get multiple OnStartContainer calls.
+  // get multiple OnStartContainer calls (e.g. from multipart/x-mixed-replace).
   bool mSentStartContainer;
 };
 
 #endif // imgRequestProxy_h__

--- a/image/test/mochitest/Makefile.in
+++ b/image/test/mochitest/Makefile.in
@@ -81,20 +81,16 @@ include $(topsrcdir)/config/rules.mk
                 test_bug89419-1.html \
                 test_bug89419-2.html \
                 test_bug552605-1.html \
                 test_bug552605-2.html \
                 bug552605.sjs \
                 bug671906-iframe.html \
                 bug671906.sjs \
                 test_bug671906.html \
-                test_bug733553.html \
-                bug733553-iframe.html \
-                bug733553.sjs \
-                animated-gif2.gif \
 		test_error_events.html \
 		error-early.png \
 		test_drawDiscardedImage.html \
                 $(NULL)
 
 # Tests disabled due to intermittent orange
 # test_bug435296.html disabled - See bug 578591
 # test_bug478398.html disabled - See bug 579139

deleted file mode 100644
--- a/image/test/mochitest/bug733553-iframe.html
+++ /dev/null
@@ -1,7 +0,0 @@
-<html>
-<head>
-<title>Bug 733553 iframe</title>
-<body>
-<img src="bug733553.sjs" id="image1" />
-</body>
-</html>

deleted file mode 100644
--- a/image/test/mochitest/bug733553.sjs
+++ /dev/null
@@ -1,77 +0,0 @@
-/* Any copyright is dedicated to the Public Domain.
- * http://creativecommons.org/publicdomain/zero/1.0/
- */
-
-var bodyPartIndex = 0;
-var bodyParts = [
-  ["red.png", "image/png"],
-  ["red.png", "image/png"], // Tests actually begin here
-  ["animated-gif2.gif", "image/gif"],
-  ["red.png", "image/png"],
-  ["lime100x100.svg", "image/svg+xml"],
-  ["big.png", "image/png"],
-  ["animated-gif2.gif", "image/gif"],
-  ["red.png", "image/png"],
-  ["lime100x100.svg", "image/svg+xml"]
-];
-var timer = Components.classes["@mozilla.org/timer;1"];
-var partTimer = timer.createInstance(Components.interfaces.nsITimer);
-
-function getFileAsInputStream(aFilename) {
-  var file = Components.classes["@mozilla.org/file/directory_service;1"]
-             .getService(Components.interfaces.nsIProperties)
-             .get("CurWorkD", Components.interfaces.nsIFile);
-
-  file.append("tests");
-  file.append("image");
-  file.append("test");
-  file.append("mochitest");
-  file.append(aFilename);
-
-  var fileStream = Components.classes['@mozilla.org/network/file-input-stream;1']
-                   .createInstance(Components.interfaces.nsIFileInputStream);
-  fileStream.init(file, 1, 0, false);
-  return fileStream;
-}
-
-function handleRequest(request, response)
-{
-  response.setHeader("Content-Type",
-                     "multipart/x-mixed-replace;boundary=BOUNDARYOMG", false);
-  response.setHeader("Cache-Control", "no-cache", false);
-  response.setStatusLine(request.httpVersion, 200, "OK");
-  // We're sending parts off in a delayed fashion, to let the tests occur.
-  response.processAsync();
-  response.write("--BOUNDARYOMG\r\n");
-  sendParts(response);
-}
-
-function sendParts(response) {
-  if (bodyParts.length > bodyPartIndex) {
-    partTimer.initWithCallback(getSendNextPart(response), 200,
-                               Components.interfaces.nsITimer.TYPE_ONE_SHOT);
-  }
-  else {
-    sendClose(response);
-  }
-}
-
-function sendClose(response) {
-  response.write("--BOUNDARYOMG--\r\n");
-  response.finish();
-}
-
-function getSendNextPart(response) {
-  var part = bodyParts[bodyPartIndex++];
-  var nextPartHead = "Content-Type: " + part[1] + "\r\n\r\n";
-  var inputStream = getFileAsInputStream(part[0]);
-  return function () {
-    response.bodyOutputStream.write(nextPartHead, nextPartHead.length);
-    response.bodyOutputStream.writeFrom(inputStream, inputStream.available());
-    inputStream.close();
-    // Toss in the boundary, so the browser can know this part is complete
-    response.write("--BOUNDARYOMG\r\n");
-    sendParts(response);
-  }
-}
-

deleted file mode 100644
--- a/image/test/mochitest/test_bug733553.html
+++ /dev/null
@@ -1,55 +0,0 @@
-<!DOCTYPE HTML>
-<html>
-<!--
-https://bugzilla.mozilla.org/show_bug.cgi?id=733553
--->
-<head>
-  <title>Test for Bug 733553</title>
-  <script type="application/javascript" src="/MochiKit/MochiKit.js"></script>
-  <script type="application/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
-  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>
-</head>
-<body>
-<a target="_blank" href="https://bugzilla.mozilla.org/show_bug.cgi?id=733553">Mozilla Bug 733553</a>
-<p id="display"></p>
-<pre id="test">
-<script type="application/javascript">
-
-SimpleTest.waitForExplicitFinish();
-
-var testIndex = 0;
-var testParts = [
-  [1, "red.png"],
-  [40, "animated-gif2.gif"],
-  [1, "red.png"],
-  [100, "lime100x100.svg"],
-  [3000, "big.png"],
-  [40, "animated-gif2.gif"],
-  [1, "red.png"]
-];
-
-function initializeOnload() {
-  var iframeelem = document.getElementById('test-iframe');
-  var firstimg = iframeelem.contentDocument.getElementById('image1');
-  firstimg.addEventListener("load", imageLoad, false);
-}
-
-function imageLoad(aEvent) {
-  if (testParts.length > testIndex) {
-    var [width, fileName] = testParts[testIndex++];
-    is(aEvent.target.width, width,
-       "Test " + (testIndex - 1) + " " + fileName + " width not correct");
-  }
-  else {
-    aEvent.target.removeEventListener("load", arguments.callee, false);
-    SimpleTest.finish();
-  }
-}
-
-</script>
-</pre>
-<div id="content"> <!-- style="display: none" -->
-<iframe id="test-iframe" src="http://mochi.test:8888/tests/image/test/mochitest/bug733553-iframe.html" onload="initializeOnload()"></iframe>
-</div>
-</body>
-</html>

--- a/layout/generic/nsImageFrame.cpp
+++ b/layout/generic/nsImageFrame.cpp
@@ -647,20 +647,17 @@ nsImageFrame::OnStopDecode(imgIRequest *
   NS_ASSERTION(imageLoader, "Who's notifying us??");
   PRInt32 loadType = nsIImageLoadingContent::UNKNOWN_REQUEST;
   imageLoader->GetRequestType(aRequest, &loadType);
   if (loadType != nsIImageLoadingContent::CURRENT_REQUEST &&
       loadType != nsIImageLoadingContent::PENDING_REQUEST) {
     return NS_ERROR_FAILURE;
   }
 
-  bool multipart = false;
-  aRequest->GetMultipart(&multipart);
-
-  if (loadType == nsIImageLoadingContent::PENDING_REQUEST || multipart) {
+  if (loadType == nsIImageLoadingContent::PENDING_REQUEST) {
     NotifyNewCurrentRequest(aRequest, aStatus);
   }
 
   return NS_OK;
 }
 
 void
 nsImageFrame::NotifyNewCurrentRequest(imgIRequest *aRequest,