1863194 - fling zooms map during scroll

Status: RESOLVED FIXED

(Core :: Panning and Zooming, defect, P3)

Description

[Timothy Nikkel (:tnikkel)]

Open https://agriculture.canada.ca/en/agricultural-production/weather/canadian-drought-monitor and place your mouse cursor in the middle of the page. Do a fling downwards to scroll down. The fling will stop when your cursor is over the map and then zoom the map.

Comment 1

[Botond Ballo [:botond]]

cc Dan, this is the sort of thing that we hoped would be fixed by bug 1168182.

Comment 2

[Timothy Nikkel (:tnikkel)]

Another page where I see this
https://zwiftinsider.com/sgurr-8/

Comment 3

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

The severity field is not set for this bug.
:botond, could you have a look please?

For more information, please visit BugBot documentation.

Comment 4

[Hiroyuki Ikezoe (:hiro)]

Note that I don't see this issue on my Linux box since, I believe, there's no momentum pan phase, it's rather FlingAnimation. If I don't do a fling, if I do rather keep panning, I can see the issue.

Comment 5

[Hiroyuki Ikezoe (:hiro)]

Attachment: a sub frame loaded in an OOP iframe

Comment 6

[Hiroyuki Ikezoe (:hiro)]

A reduced test case is; data:text/html,<iframe src="https://bug1863194.bmoattachments.org/attachment.cgi?id=9368590" style="margin-top: 30vh; margin-bottom:100vh;width: 80vw; height:40vh">

So, this is because a wheel event listener doing preventDefault() in a cross-origin iframe.

And as Dan pointed out to me in our weekly meeting, this check in UpdateWheelEventTarget is related. I confirmed dropping the check fixes this bug, I am not sure whether we can simply drop it or not though.

Comment 7

[Dan Robertson (:dlrobertson)]

(In reply to Hiroyuki Ikezoe (:hiro) from comment #6)

A reduced test case is; data:text/html,<iframe src="https://bug1863194.bmoattachments.org/attachment.cgi?id=9368590" style="margin-top: 30vh; margin-bottom:100vh;width: 80vw; height:40vh">

So, this is because a wheel event listener doing preventDefault() in a cross-origin iframe.

And as Dan pointed out to me in our weekly meeting, this check in UpdateWheelEventTarget is related. I confirmed dropping the check fixes this bug, I am not sure whether we can simply drop it or not though.

I think the check can be dropped. IIRC I added that check largely just because I thought it seemed like the right thing to do, but I didn't think about bugs like this.

Comment 8

[Dan Robertson (:dlrobertson)]

Attachment: Bug 1863194 - Do not terminate wheel transaction on browsing context change. r=hiro,smaug,#webdriver-reviewers

We should continue to use a wheel transaction for wheel events when the
browsing context changes from the current context. Avoiding the override
of the event target with the current wheel transaction can halt a page
scroll when the mouse moves over a out-of-process subframe.

Comment 9

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/f946717df0fd
Do not terminate wheel transaction on browsing context change. r=hiro,smaug

Comment 10

[Sandor Molnar[:smolnar]]

Backed out for causing wd failures @ webdriver/tests/bidi/input/perform_actions/wheel.py

Backout link: https://hg.mozilla.org/integration/autoland/rev/e0428c780b518e590137a3f9eece3a415d35e5df

Push with failures

Failure log -> TEST-UNEXPECTED-FAIL | /webdriver/tests/bidi/input/perform_actions/wheel.py | test_scroll_shadow_tree[outer-closed] - assert 0 == 1

Comment 11

[Dan Robertson (:dlrobertson)]

I haven't been able to reproduce this locally, but I'll try to repro via a try push.

Comment 12

[Dan Robertson (:dlrobertson)]

This now happens on google searches for me. For example, when searching for a particular location near me, if I scroll down the page over the map of nearby points of interest, the map zooms out.

Comment 13

[Timothy Nikkel (:tnikkel)]

Did google maps change? Did we change?

Comment 14

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/3ea5312f88de
Do not terminate wheel transaction on browsing context change. r=hiro,smaug,webdriver-reviewers,Sasha

Comment 15

[Cosmin Sabou [:CosminS]]

https://hg.mozilla.org/mozilla-central/rev/3ea5312f88de