https://searchfox.org/mozilla-central/rev/95cf843de977805a3951f9137f5ff1930599d94e/gfx/layers/apz/util/TouchActionHelper.cpp#24

This needs fixing for proper support of touch-action:pinch-zoom. I forgot about this code when I mentored bug 1329241 with the rest of the implementation.

The TouchActionHelper codepath is only used in some fallback scenarios, so I'm not sure if a lot of real world sites would be affected. I only realized the problem due to unrelated code browsing. It's a pretty small fix, I'll try to write a test that exercises the scenario as well. We'll want to uplift to 85 so it rides with bug 1329241.

https://treeherder.mozilla.org/#/jobs?repo=try&revision=5ec6930a24c51cfb9d7b8a8bbe5213a7aef478aa

Oops. This should be better: https://treeherder.mozilla.org/#/jobs?repo=try&revision=da4d2a919cd0b5820c243bdec9f8cceb0d20abb8

The code in TouchActionHelper didn't get updated with the
rest of the touch-action:pinch-zoom implementation. This
patch corrects that and adds a test that exercises the
relevant scenario.

https://hg.mozilla.org/mozilla-central/rev/87d37f9061c7

Comment on attachment 9192944 [details]
Bug 1682170 - Update TouchActionHelper to support touch-action:pinch-zoom. r?botond

Beta/Release Uplift Approval Request

• User impact if declined: In some cases, web content with touch-action:pinch-zoom may not work as intended.
• Is this code covered by automated tests?: Yes
• Has the fix been verified in Nightly?: No
• Needs manual test from QE?: No
• If yes, steps to reproduce:
• List of other uplifts needed: None
• Risk to taking this patch: Low
• Why is the change risky/not risky? (and alternatives if risky): Pretty small, well-understood change. Comes with test.
• String changes made/needed: none

Comment on attachment 9192944 [details]
Bug 1682170 - Update TouchActionHelper to support touch-action:pinch-zoom. r?botond

approved for 85.0b2

https://hg.mozilla.org/releases/mozilla-beta/rev/cfaf16c49656