1303903 - No longer fire DOMMouseScroll event on browser while the | menupopup, panel | is displayed

Status: RESOLVED WONTFIX

(Core :: Widget, defect, P3)

Description

[Alice0775 White]

my addon[1] stops working after landing bug 982121.

[1] https://addons.mozilla.org/en-US/firefox/addon/bug643770stop-autoscroll-by


Steps to Reproduce:
0. Enable chrome debug. i.e. devtools.chrome.enabled=true
1. Open Browser Console and Scratchpad
2. Run the following code as browser code
    window.addEventListener("DOMMouseScroll", function(event) {
      console.log("DOMMouseScroll");
    }, true);

3. Open any popup such as menupopup, contextmenu, autoscroll marker
4. Turn mouse wheel on browser (not on the popup)

Actual Results:
The wheel event does not fire

Expected Results:
The wheel event should fire

Regression window:
https://hg.mozilla.org/integration/fx-team/pushloghtml?fromchange=c6e90a3857c019e418c113f31dec86ca43e60243&tochange=4cab5471b2fa42dd7d0560f8f35dcc4e82a9414e

Regressed by:
4cab5471b2fa	Gijs Kruitbosch — Bug 982121 - consume wheel events when popups are open, r=enndeakin

Comment 1

[Jim Mathies [:jimm]]

Expected behavior from the work in bug 982121?

Comment 2

[:Gijs (he/him)]

(In reply to Jim Mathies [:jimm] from comment #1)
> Expected behavior from the work in bug 982121?

I think so. Doublechecking with Neil.

Comment 3

[Neil Deakin]

Yes, this would be expected.

Comment 4

[Alice0775 White]

I do not agree. I think this is just unexpected side effect of bug 982121.

And I can agree that the event does not fire if it is bubbling phase.
However, The event should fire, because the listener is attached to the top most browser element and capturing phase. 

And this is braking addon. There are no workaround.

Comment 5

[Alice0775 White]

I suggest that bug 982121 should be backed out.

Comment 6

[Neil Deakin]

We should instead just fix 213496/643770 (which are duplicates, I think)

Comment 7

[Marcia Knous [:marcia]]

Tracking 52+ since this affects extension compat.

Comment 8

[Andrew Overholt [:overholt]]

Neil clarified for me that what he meant by comment 6 was that fixing bug 213496 (or the potential-dupe bug 643770), we would obviate the need for the addon that got broken but the change in bug 982121. Neil said he'd take a look at how hard it would be to fix bug 213496 (or bug 643770) so I'll set needinfo here to keep it in his queue. Thanks, Neil.

Comment 9

[Neil Deakin]

The patch in bug 643770 will fix the underlying bug the addon was created for. The addon could just add rolluponmousewheel to the popup as well as the patch there does and have this work in current releases, and has the benefit that it will work on Mac and Linux as well, which the addon doesn't handle as far as I can tell.

Comment 10

[Alice0775 White]

(In reply to Neil Deakin from comment #9)
> The patch in bug 643770 will fix the underlying bug the addon was created
> for. The addon could just add rolluponmousewheel to the popup as well as the
> patch there does and have this work in current releases, and has the benefit
> that it will work on Mac and Linux as well, which the addon doesn't handle
> as far as I can tell.


What about the event capture phase and it is targeted root window .
The event is no longer fired.

I do not understand why?

Comment 11

[Marcia Knous [:marcia]]

Tracking 52- based on bug resolution.