Here is a list of some relevant bugs from bugzilla.mozilla.org:
Original MNG support, and outcry upon MNG removal.
Libmng footprint reduction.
Libpng footprint reduction.
Checkins of June 2 or June 3, 2003, that may have broken MNG/JNG support.
Other bugs that we will fix:
JNG compiler optimization bug.
Fix checked in to 1.4.x branch 15 Dec 03! Thanks, mkaply.
Many windows opening when trying to view an unsupported format. At first
we thought this was a MNG bug but we see it if we remove JPEG support and
try to view a jpeg, regardless of whether opi's patch has been applied or
not. UPDATE 7 Feb 05: Chris Biesinger has uploaded a patch that appears to
fix the problem. UPDATE 18 Feb 05: Chris' patch has been checked in to trunk
and Firefox branch of CVS.
Other bugs that we might as well fix if we can:
Chrome should use PNG instead of GIF.
bug #75558 and
Alpha channel scaling bug. MNG and JNG, but not GIF, have the
same problem as well. A patch has been approved and was checked in to
the trunk on 23 November 2003.
libpng namespace bug (checked in to trunk on 31 October 2003). We can use
"MOZ_" prefix in libmng as well.
Third-party library namespace bug.)
Use bicubic interpolation when displaying interlace passes.
Work with W3C on standardizing MNG.
There was no bug report for this, but as illustrated at the bottom of the
opossum demo, MNG and JNG were not
useable as CSS background images. This was reported on March 5, 2004, in
and immediately fixed by Alexander Opitz with the following little patch:
+ mObserver->OnStopFrame(nsnull, NS_REINTERPRET_CAST(imgContainerMNG*,
+ mObserver->OnStopContainer(nsnull, mImageContainer);
+ mObserver->OnStopDecode(nsnull, NS_OK, nsnull);