Bug 517543 - need a STATUS_DECODE_COMPLETE for imgIRequest.r=joe

layout/xul/base/src/tree/src/nsTreeBodyFrame.cpp

@@ -2175,8 +2175,10 @@ nsTreeBodyFrame::GetImage(PRInt32 aRowIndex, nsTreeColumn* aCol, PRBool aUseCont
     imgIRequest *imgReq = entry.request;
     imgReq->GetImageStatus(&status);
     imgReq->GetImage(aResult); // We hand back the image here.  The GetImage call addrefs *aResult.
-    PRBool animated = PR_FALSE;
-    if (*aResult)
+    PRBool animated = PR_TRUE; // Assuming animated is the safe option
+
+    // We can only call GetAnimated if we're decoded
+    if (*aResult && (status & imgIRequest::STATUS_DECODE_COMPLETE))
       (*aResult)->GetAnimated(&animated);
 
     if ((!(status & imgIRequest::STATUS_LOAD_COMPLETE)) || animated) {

modules/libpr0n/public/imgIContainer.idl

@@ -85,7 +85,10 @@ interface imgIContainer : nsISupports
   readonly attribute PRInt32 height;
 
   /**
-   * Whether this image is animated.
+   * Whether this image is animated. You can only be guaranteed that querying
+   * this will not throw if STATUS_DECODE_COMPLETE is set on the imgIRequest.
+   *
+   * @throws NS_ERROR_NOT_AVAILABLE if the animated state cannot be determined.
    */
   readonly attribute boolean animated;
 

modules/libpr0n/public/imgIRequest.idl

@@ -90,6 +90,8 @@ interface imgIRequest : nsIRequest
    *
    * STATUS_FRAME_COMPLETE: The first frame has been
    * completely decoded.
+   *
+   * STATUS_DECODE_COMPLETE: The whole image has been decoded.
    */
   //@{
   const long STATUS_NONE             = 0x0;
@@ -98,6 +100,7 @@ interface imgIRequest : nsIRequest
   const long STATUS_LOAD_COMPLETE    = 0x4;
   const long STATUS_ERROR            = 0x8;
   const long STATUS_FRAME_COMPLETE   = 0x10;
+  const long STATUS_DECODE_COMPLETE  = 0x20;
   //@}
 
   /**

modules/libpr0n/src/imgContainer.cpp

@@ -152,6 +152,7 @@ imgContainer::imgContainer() :
   mDiscardTimer(nsnull),
   mHasSourceData(PR_FALSE),
   mDecoded(PR_FALSE),
+  mHasBeenDecoded(PR_FALSE),
   mDecoder(nsnull),
   mWorker(nsnull),
   mBytesDecoded(0),
@@ -299,6 +300,7 @@ NS_IMETHODIMP imgContainer::ExtractFrame(PRUint32 aWhichFrame,
   img->Init(nsnull, "", INIT_FLAG_NONE);
   img->SetSize(aRegion.width, aRegion.height);
   img->mDecoded = PR_TRUE; // Also, we need to mark the image as decoded
+  img->mHasBeenDecoded = PR_TRUE;
 
   // If a synchronous decode was requested, do it
   if (aFlags & FLAG_SYNC_DECODE) {
@@ -483,8 +485,20 @@ NS_IMETHODIMP imgContainer::GetAnimated(PRBool *aAnimated)
 
   NS_ENSURE_ARG_POINTER(aAnimated);
 
-  *aAnimated = (mAnim != nsnull);
-  
+  // If we have mAnim, we can know for sure
+  if (mAnim) {
+    *aAnimated = PR_TRUE;
+    return NS_OK;
+  }
+
+  // Otherwise, we need to have been decoded to know for sure, since if we were
+  // decoded at least once mAnim would have been created for animated images
+  if (!mHasBeenDecoded)
+    return NS_ERROR_NOT_AVAILABLE;
+
+  // We know for sure
+  *aAnimated = PR_FALSE;
+
   return NS_OK;
 }
 
@@ -953,6 +967,7 @@ NS_IMETHODIMP imgContainer::DecodingComplete(void)
   // XXX - these should probably be combined when we fix animated image
   // discarding with bug 500402.
   mDecoded = PR_TRUE;
+  mHasBeenDecoded = PR_TRUE;
   if (mAnim)
     mAnim->doneDecoding = PR_TRUE;
 

modules/libpr0n/src/imgContainer.h

@@ -327,6 +327,7 @@ private: // data
 
   // Do we have the frames in decoded form?
   PRBool                     mDecoded;
+  PRBool                     mHasBeenDecoded;
 
   friend class imgDecodeWorker;
 

modules/libpr0n/src/imgRequest.cpp

@@ -681,6 +681,10 @@ NS_IMETHODIMP imgRequest::OnStopDecode(imgIRequest *aRequest,
   // entry size to take this into account.
   UpdateCacheEntrySize();
 
+  // If we were successful, set STATUS_DECODE_COMPLETE
+  if (NS_SUCCEEDED(aStatus))
+    mImageStatus |= imgIRequest::STATUS_DECODE_COMPLETE;
+
   // ImgContainer and everything below it is completely correct and
   // bulletproof about its handling of decoder notifications.
   // Unfortunately, here and above we have to make some gross and
@@ -711,7 +715,8 @@ NS_IMETHODIMP imgRequest::OnDiscard(imgIRequest *aRequest)
   mState &= ~stateBitsToClear;
 
   // Clear the status bits we no longer deserve.
-  PRUint32 statusBitsToClear = imgIRequest::STATUS_FRAME_COMPLETE;
+  PRUint32 statusBitsToClear = imgIRequest::STATUS_FRAME_COMPLETE
+                               | imgIRequest::STATUS_DECODE_COMPLETE;
   mImageStatus &= ~statusBitsToClear;
 
   // Update the cache entry size, since we just got rid of frame data