1199433 - First notch of wheel scroll is ignored

Status: RESOLVED WORKSFORME

(Core :: Widget: Gtk, defect)

Description

[Ian Nartowicz]

User Agent: Mozilla/5.0 (X11; Linux i686; rv:38.0) Gecko/20100101 Firefox/38.0
Build ID: 20150514102509

Steps to reproduce:

1. Open page with vertical scrollbar
2. Move the mouse pointer from outside the Firefox window to within the content area
3. Roll the mouse wheel one notch
4. Toll a second notch


Actual results:

The first notch does nothing.  The second and subsequent wheel rolls work as expected.


Expected results:

First notch should scroll too.

This is recent, perhaps only in the last couple of weeks, and may be Linux only.  It has been reproduced on Cinnamon and Openbox.  One person has reported it on Windows 7.  It may occur when a page is first loaded, but bringing the mouse from outside the window is easier to reproduce.

Comment 1

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

Do you have the pref layers.async-pan-zoom.enabled set to true or false? If it is set to false, can you use mozregression to find a regression window?

Comment 2

[Ian Nartowicz]

mozregression says:
Last good revision: 1ee54e043b9b
First bad revision: 939320b957c5
Pushlog: https://hg.mozilla.org/integration/mozilla-inbound/pushloghtml?fromchange=1ee54e043b9b&tochange=939320b957c5

Comment 3

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

Thanks!

Comment 4

[AnAkkk]

Maybe related to https://bugzilla.mozilla.org/show_bug.cgi?id=1182700

Comment 5

[Andrew Comminos [:acomminos]]

This is an upstream bug with GDK_SCROLL_SMOOTH; see https://bugzilla.redhat.com/show_bug.cgi?id=1226706.

Comment 6

[GetOperational]

Can confirm I experience this with Firefox nightly on Ubuntu 15.04 on Cinnamon UI.
Also happens with a blank Firefox profile, no add-ons.

Mozilla/5.0 (X11; Linux x86_64; rv:43.0) Gecko/20100101 Firefox/43.0

Comment 7

[Ian Nartowicz]

There are at least two upstream bugs raised in Gnome.  One describes this situation exactly.  The other seems more closely related to bug 1182700.  A patch was produced to fix both, but backed out for causing other problems.  It looks for all the world like something that just happened recently (GTK 3.16) but I don't even have GTK 3.16 and I see problems.  Maybe they've been there all along and I never noticed until Firefox flipped to GTK3.

Comment 8

[Ian Nartowicz]

I have reproduced this problem in other applications going back as far as GTK 3.4 (possibly older, but I don't have older versions to test), so definitely a longstanding GTK3 problem.  I guess I just don't use wheel scrolling much in other applications and never noticed.

Comment 9

[Ian Nartowicz]

Did this go away?  I don't seem to be able to reproduce it in nightly any more.

Comment 10

[GetOperational]

The bug seems to have gone away for me as well.

Firefox nightly 46.0a1 (2015-12-23)
Ubuntu 15.10
Cinnamon ui 2.8.6

Comment 11

[Ian Nartowicz]

It isn't an upstream fix.  I can still get the problem in other GTK3 apps.  What happened?  Is it because XINPUT2 was disabled?