Some CSS-filters broken in Firefox Nightly 48/49+

[metasieben]

Environment

Firefox: 48+ rev >= ae7413abfa4d3954a6a4ce7c1613a7100f367f9a
AdblockPlus: 2.7.3.4174-beta

Every Nightly version after 2016-04-18 shows this behaviour.

How to reproduce

1. add this to the custom filters: twitch.tv##div[class='clearfix upsell-banner recent-past-broadcast']
2. go here: ​https://www.twitch.tv/previouslyrecorded_live

Observed behaviour

3. (if channel ist offline) there is a banner >Watch PreviouslyRecorded_Live's Last Broadcast!< with the class 'div.clearfix.upsell-banner.recent-past-broadcast' which should not be visible.

Expected behaviour

3. (if channel ist offline) banner with the class 'div.clearfix.upsell-banner.recent-past-broadcast' should be blocked.

somewhere between these Nightly versions(18.04. / 19.04.) something changed in Firefox and ADP is no longer able to block these styles?

here the regression-range:
​https://hg.mozilla.org/integration/mozilla-inbound/pushloghtml?fromchange=1f16d3da9280e40ada252acf8110b91ee1edbb08&tochange=ae7413abfa4d3954a6a4ce7c1613a7100f367f9a

[metasieben]

mozilla-central pushlog: ​https://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=1f16d3da9280e40ada252acf8110b91ee1edbb08&tochange=ae7413abfa4d3954a6a4ce7c1613a7100f367f9a

[trev]

Do you happen to use Mac OS X? Because ​bug 1187099 is back and I just filed #4139 on addressing this.

[metasieben]

yes, i am.

[trev]

Let's resolve this issue as a duplicate then, #4139 is already under review.