1405504 - Can no longer scroll the tab bar using touch on win 10 and Firefox beta 57.0b5. Touch scrolling works on Firefox 56.

Status: UNCONFIRMED

(Firefox :: Tabbed Browser, defect, P2)

Description

[alex.n.lowe]

After attempting to update to Firefox from version 56 to 57.0b5 beta, I found that I am unable to use the touch screen to scroll on the tab bar. Touch scrolling works perfectly fine on web pages, but I was unable to get the tab bar to move at all using the touch interface. My hardware is a Microsoft Surface pro 3 using the latest version of Windows 10 with all the updates installed. Because migrating to version 57 literally broke all my addons except uBlock Origin, it was easy to verify that the bug still occurs with no addons enabled. A new profile does not fix the issue either.

This is a regression from Firefox 56 to Firefox 57 beta, but I am unsure if it has been fixed in the nightly versions, and I was unable to locate any similar reported issues on Bugzilla, so I don’t know if this is a local issue or an issue that will affect more users. Hopefully someone else can confirm the issue or direct me to a version of Firefox where the issue has been fixed.

To reproduce this issue, create/open a new profile on Firefox 57.0b5, press ctrl+t about 50 times, and attempt to scroll the tab bar using a touch interface. Compare results between Firefox 56 and 57 to see the regression.

There is a possibly related issue: scrolling by using the surface track pad is significantly slower in Firefox 57 beta than the Firefox 56 release version. I'm unsure if it’s related to being unable to scroll using the touch interface, but it is unpleasant and it compounds the main issue. To define exactly what "slower" is, in 57 beta, slowly scroll both fingers across the length of the track pad only moves two tabs off the viewable area, and quickly swiping moves about half the tabs out of view. In Firefox 56, (and for the past few years I've had my surface) slowly scrolling both fingers across the track pad will move about half the tabs out of view, and quickly swiping the track pad will move from one end to the other end of any sane number of tabs. (I’m testing with 51 tabs.) The slow scrolling issue seems to get worse when the tab bar is almost about to hit one end of the tabs.

I am more than willing to help out with any additional information.

Comment 1

[[:philipp]]

hi, i am not able to reproduce the problem on a different touchscreen device with a similar form factor (lenovo miix 510). does this happen in normal or windows tablet mode and with a keyboard attached or not?

also if you could use the mozrgression tool from https://mozilla.github.io/mozregression/ in order to dig up a pushlog url for when the problem first started it may be very helpful to us in understanding the issue and getting it solved - there is a howto video on that page that explains the process...

Comment 2

[Cosmin Muntean [:cmuntean], Ecosystem QA]

I have managed to reproduce this issue on a Dell laptop with touch screen and on Microsoft Surface Pro 4 on latest Beta 57.0b6 using a new clean profile. But, after restart the issue is no longer reproducible. It seems that the same behavior can be observed on latest Firefox (56.0) release.
I have also tested this issue on latest Nightly (58.0a1) build, but the issue is not reproducible even if I'm using a new clean profile.

Alex, you can reproduce the issue even after restarting the browser? Also, can you please retest this issue on latest Nightly (58.0a1) build?

I have tried to use the mozregression tool in order to find what issue caused this and also what fixed this, but I haven't managed to find a bad build.

Philipp, can you also please test this using a new clean profile on your device?

Comment 3

[[:philipp]]

yes, i can replicate your results there: broken at first run in a new profile on release and beta, working on nightly (& esr52) and not reproducible via mozregression either.

Comment 4

[:Gijs (out for now; he/him)]

(In reply to alex.n.lowe from comment #0)
> There is a possibly related issue: scrolling by using the surface track pad
> is significantly slower in Firefox 57 beta than the Firefox 56 release
> version.

FWIW, this is tracked in bug 1403563. The touch stuff is still something to figure out, though, so if you could reply to the questions raised by other commenters that would be helpful.

Comment 5

[Kartikaya Gupta (email:[e-mail])]

I strongly suspect that the original reporter had e10s disabled in 56 (probably because of the addons he mentioned) and so wasn't getting APZ touch scrolling. In 57 without the addons e10s+APZ will be enabled and would result in the different behaviour. However I don't have a theory for the "first run" breakage reported by others; we used to have that issue with accessibility code disabling e10s after the first run but I thought that was resolved a while ago.

Comment 6

[BugBot [:suhaib / :marco/ :calixte]]

Redirect a needinfo that is pending on an inactive user to the triage owner.
:dao, since the bug has high priority, could you have a look please?

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