878705 - Clicking near scrollbar thumb scrolls down a page

Status: VERIFIED FIXED

(Core :: Widget: Cocoa, defect)

Description

[Jesse Ruderman]

1. Load a page that scrolls
     (e.g. https://www.squarefree.com/)
2. Scroll to make the scrollbar appear.
     (e.g. using two fingers on the trackpad)
3. Click 1 pixel or 2 pixels to the LEFT of the scrollbar thumb.

Result: Firefox scrolls down a page, as if I had clicked BELOW the thumb.

Comment 1

[Jesse Ruderman]

Attachment: screenshot showing where to click

Comment 2

[Markus Stange [:mstange]]

Attachment: patch

The left border of the scrollbar isn't covered by the scrollbar thumb, so clicks to it don't end up in nsSliderFrame::StartDrag, but in nsSliderFrame::HandlePress (normal case) or in the scroll-to-click branch of nsSliderFrame::HandleEvent (scroll-to-click case).
This patch makes us ignore clicks next to the thumb.

Comment 3

[Markus Stange [:mstange]]

Attachment: patch

Comment 4

[Robert Strong (they/them - no direct email)]

Markus, is this ready to be pushed? If so, I can land it if you like.

Comment 5

[Markus Stange [:mstange]]

Unfortunately not yet. Tryserver found a bug in the patch, there's one condition that I missed in the refactoring.

Comment 6

[Markus Stange [:mstange]]

Attachment: patch

The previous patch didn't make sure that clicking with the wrong mouse button causes no scrolling. It only checked it for the scroll-to-click case.

Comment 7

[Markus Stange [:mstange]]

https://hg.mozilla.org/integration/mozilla-inbound/rev/1ac9367a6c23

Comment 8

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/mozilla-central/rev/1ac9367a6c23

Comment 9

[Robert Strong (they/them - no direct email)]

Markus, would you have a problem with uplifting this to Aurora? If not, could you request approval for aurora? Thanks!

Comment 10

[Robert Strong (they/them - no direct email)]

comment #9

Comment 11

[Markus Stange [:mstange]]

Comment on attachment 760775 [details] [diff] [review]
patch

[Approval Request Comment]
Bug caused by (feature/regressing bug #): bug 636564
User impact if declined: unintended scrolling when clicking in the wrong place
Testing completed (on m-c, etc.): 5 days on mozilla-central
Risk to taking this patch (and alternatives if risky): low risk
String or IDL/UUID changes made by this patch: none

Comment 12

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/releases/mozilla-aurora/rev/38342c15a73b

Comment 13

[Bogdan Maris, Desktop QA]

Mozilla/5.0 (Macintosh; Intel Mac OS X 10.9; rv:23.0) Gecko/20100101 Firefox/23.0

Verified as fixed on Firefox 23 beta 9 (buildID: 20130725195523) and latest Nightly (buildID: 20130725171558).

Comment 14

[Bogdan Maris, Desktop QA]

Mozilla/5.0 (Macintosh; Intel Mac OS X 10.7; rv:24.0) Gecko/20100101 Firefox/24.0
Mozilla/5.0 (Macintosh; Intel Mac OS X 10.7; rv:26.0) Gecko/20100101 Firefox/26.0

Verified as fixed on Firefox 24 beta 2 (buildID: 20130812173056) and latest Nightly (buildID: 20130813030205).