main/libpng: Regression in edge?
A few days ago, APNG support was disabled in libpng, because of a problem with rendering in Chromium.
So far as I could tell, the problem is that Chromium implements it's own APNG decoder, which clashes with libpng builds that have APNG decoding enabled by the patch. This has always been the case, but only now a user needed APNGs to work in Chromium without flickering and requested APNG support to be removed from libpng.
I understand that if a problem can be solved by removing a patch, this will always be the preferred solution. However, APNG support was added to libpng in Alpine more than a decade ago, so I would argue that removing APNG support now is not a good solution, as for all this time users could depend on libpng in Alpine having APNG support when writing their applications.
Another problem is that all Mozilla products will now have to use the bundled libpng. It's never good to rely on bundled libraries, as it takes much longer for CVEs to be patched than in a system library. In general on Linux, Firefox is the most popular browser, so I assume this is also true for Alpine Linux, which means that more users would be affected.
I therefore suggests the following:
- Commit 301074dd is reverted so APNG is again supported with system libpng.
- Commit 3f616f19, 321f5476, c004295d and bd5ffea5 are reverted so all Mozilla products again are linked against system libpng.
- Chromium is rebuild with bundled libpng so APNGs will not flicker.
What do you think about this?