LWN: Comments on "Firefox 69.0 released"

Firefox 69.0 released

flussence — Sun, 15 Sep 2019 19:52:09 +0000

GIFs can be streamed, as can MJPEGs. The code to do so was written a quarter century ago, but in the intervening time the ability for the user to stop playback by pressing Escape was taken away.

Firefox 69.0 released

tialaramex — Sun, 08 Sep 2019 19:35:03 +0000

What would it mean to prevent the whole GIF animation from loading?

You would only know this is animated after loading and parsing the GIF. Maybe, if it is streamed already, you can stop the stream, but it may just not be streamed, I don't know.

Trying to act on partial data is a fool's game, this is where loads of nasty Oracle bugs in cryptographic code arise, if you insist on doing full recognition first before acting on the data you never get into trouble this way. If GIFs can be streamed (again, I don't know) then somebody has to already do all the heavy lifting to cope with partial recognition safely, but if not you're adding a LOT of fragile code.

Firefox 69.0 released

roc — Fri, 06 Sep 2019 11:10:54 +0000

I don't have the reference in front of me, but in HN a Mozilla developer mentioned that checking whether a file exists can cost several ms on Windows with a HDD. And these files are on the critical startup path, on every startup, neither of which "phone-home requests" are.

Firefox 69.0 released

flussence — Thu, 05 Sep 2019 23:24:46 +0000

How much does one CSS file cost startup performance, compared to, say, the ~15MB of phone-home requests it makes on first run? Do they have actual benchmarks or is this just someone making busywork?

Firefox 69.0 released

sroracle — Thu, 05 Sep 2019 07:35:37 +0000

Indeed: Firefox 68 ships with logic to automatically enable this about:config switch if userChrome.css / userContent.css is already used. See Bugzilla #1541233 and #1550157.

Firefox 69.0 released

bartoc — Wed, 04 Sep 2019 21:21:20 +0000

Does it prevent the whole animation from loading though? Or just from playing

Firefox 69.0 released

apoelstra — Wed, 04 Sep 2019 16:22:07 +0000

An important part of the release notes

>Firefox no longer loads userChrome.css or userContent.css by default improving start-up performance. Users who wish to customize Firefox by using these files can set the toolkit.legacyUserProfileCustomizations.stylesheets preference to true to restore this ability

I believe (from various Reddit threads) that if you update from Firefox 68 that this option will be set automatically but I'm not sure if that requires auto-updating or anything like that.

Among many many other things, userChrome.css is needed to hide the original tab bar when using TreeStyleTab, so users of TST may find (yet again) that their Firefox has visibly broken with this update. Setting the about:config setting and restarting fixes it.

Firefox 69.0 released

spiroharvey — Wed, 04 Sep 2019 07:01:55 +0000

AMAZING! Now my life is complete.
Thank you, you're on my Christmas card list.

Firefox 69.0 released

zwenna — Wed, 04 Sep 2019 06:31:34 +0000

> Next I'd love to see an option to permanently disable animations on GIFs. :)

image.animation_mode has been there for 15+ years.

Firefox 69.0 released

spiroharvey — Wed, 04 Sep 2019 06:07:28 +0000

That's great blocking autoplaying videos. I wasn't actually aware the feature was already there to stop sound playing, so it's nice too they're making strides in this area.

Next I'd love to see an option to permanently disable animations on GIFs. :)