For multipart images we create a MultipartImage which contains each part. Each part in turn is a VectorImage or RasterImage. The MultipartImage and each part image all have their own ProgressTracker. The ProgressTracker for the MultipartImage observes the notifications of each part image via the IProgressObserver interface. This interfaces notably has no way to notify about an image error. So when a part image has an error it never gets propagated to the MultipartImage's ProgressTracker. This confuses our assertions about consistency of progress notifications. In this case we expect that when we get the load complete notification then we either have the size of the image or we encountered an error. So if the first part of a multipart image is broken and we are unable to get a size from it we will trigger this assertion.
There are two ways to fix this. One would be to propagate errors to the MultipartImage's ProgressTracker. This would put the ProgressTracker for the MultipartImage permanently into error state and prevent showing the images from the remaining parts if one part image had an error.
So in this patch I create a way to tell a ProgressTracker that is is for a multipart image, and use that to relax the assertions. As far as I can tell our code should be able to handle "ignoring" an error in a bad part image.
Addtionaly there is a way that an error flag can get propagated to the MultipartImage's tracker: in MultipartImage::FinishTransition we get the progress directly from the part image and notify for it. This seems like an oversight as the comment at
https://dxr.mozilla.org/mozilla-central/rev/bfa85d23df57c8a1db17c99b267667becc1c4afd/image/imgRequest.cpp#989
indicates that we don't want one bad part to prevent later parts from displaying. So we add the error flag to the ones we filter out when we propagate progress.
I found these issues locally by moving all of imagelib's .cpp files to SOURCES instead of UNIFIED_SOURCES. (That change isn't part of this patch, though.)
MozReview-Commit-ID: 97Xpfu8eFE6
The bulk of this commit was generated with a script, executed at the top
level of a typical source code checkout. The only non-machine-generated
part was modifying MFBT's moz.build to reflect the new naming.
CLOSED TREE makes big refactorings like this a piece of cake.
# The main substitution.
find . -name '*.cpp' -o -name '*.cc' -o -name '*.h' -o -name '*.mm' -o -name '*.idl'| \
xargs perl -p -i -e '
s/nsRefPtr\.h/RefPtr\.h/g; # handle includes
s/nsRefPtr ?</RefPtr</g; # handle declarations and variables
'
# Handle a special friend declaration in gfx/layers/AtomicRefCountedWithFinalize.h.
perl -p -i -e 's/::nsRefPtr;/::RefPtr;/' gfx/layers/AtomicRefCountedWithFinalize.h
# Handle nsRefPtr.h itself, a couple places that define constructors
# from nsRefPtr, and code generators specially. We do this here, rather
# than indiscriminantly s/nsRefPtr/RefPtr/, because that would rename
# things like nsRefPtrHashtable.
perl -p -i -e 's/nsRefPtr/RefPtr/g' \
mfbt/nsRefPtr.h \
xpcom/glue/nsCOMPtr.h \
xpcom/base/OwningNonNull.h \
ipc/ipdl/ipdl/lower.py \
ipc/ipdl/ipdl/builtin.py \
dom/bindings/Codegen.py \
python/lldbutils/lldbutils/utils.py
# In our indiscriminate substitution above, we renamed
# nsRefPtrGetterAddRefs, the class behind getter_AddRefs. Fix that up.
find . -name '*.cpp' -o -name '*.h' -o -name '*.idl' | \
xargs perl -p -i -e 's/nsRefPtrGetterAddRefs/RefPtrGetterAddRefs/g'
if [ -d .git ]; then
git mv mfbt/nsRefPtr.h mfbt/RefPtr.h
else
hg mv mfbt/nsRefPtr.h mfbt/RefPtr.h
fi
