1509710 - "pointermove" events should not trigger when dragging a scrollbar handle

Status: RESOLVED FIXED

(Core :: DOM: UI Events & Focus Handling, defect, P3)

Description

[romain.petit.entreprise]

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/70.0.3538.110 Safari/537.36

Steps to reproduce:

Drag a scrollbar handle using cursor, please see this fiddle:
https://jsfiddle.net/vafp2yxj/


Actual results:

While dragging the scroll handle, the "pointermove" event is triggered.


Expected results:

The "pointermove" event should not be triggered.

There is no clear spec about this, but from javascript point of view there is no way to detect that the user is dragging the scroll handle, so all js listener will likely interfer with native scrolling.
Not triggering the "pointermove" event is the choice made by other major browsers, FF is the only one acting like this.

Comment 1

[Edgar Chen [:edgar]]

Attachment: Bug 1509710 - Prevent dispatching pointermove events targeted at a slider frame to web content, if the scrollbar is being dragged;

Comment 2

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/c2d9108fee93
Prevent dispatching pointermove events targeted at a slider frame to web content, if the scrollbar is being dragged; r=smaug

Comment 3

[Sandor Molnar[:smolnar]]

Backed out for causing mochitest failures in test_pointermove_drag_scrollbar

Backout link: https://hg.mozilla.org/integration/autoland/rev/a1fde5b38e5aa0c0c56a4be016703e9fcd44a21e

Push with failures: https://treeherder.mozilla.org/jobs?repo=autoland&selectedTaskRun=C03yG4rWSEaBnzyo_yYiPQ.0&resultStatus=testfailed%2Cbusted%2Cexception%2Crunning%2Cpending%2Crunnable&revision=c2d9108fee938f4ce0031f47ce2195895b6a898a&searchStr=mochi%2Cplain

Failure log: https://treeherder.mozilla.org/logviewer?job_id=327823664&repo=autoland&lineNumber=2386

"INFO - TEST-START | dom/events/test/pointerevents/test_pointermove_drag_scrollbar.html
[task 2021-01-26T13:06:41.976Z] 13:06:41 INFO - Buffered messages logged at 13:06:36
[task 2021-01-26T13:06:41.977Z] 13:06:41 INFO - add_task | Entering test test_pointer_mouse_event
[task 2021-01-26T13:06:41.977Z] 13:06:41 INFO - TEST-PASS | dom/events/test/pointerevents/test_pointermove_drag_scrollbar.html | should receive pointerdown event
[task 2021-01-26T13:06:41.977Z] 13:06:41 INFO - Buffered messages finished
[task 2021-01-26T13:06:41.977Z] 13:06:41 WARNING - TEST-UNEXPECTED-FAIL | dom/events/test/pointerevents/test_pointermove_drag_scrollbar.html | should not receive pointermove event
[task 2021-01-26T13:06:41.977Z] 13:06:41 INFO - SimpleTest.ok@SimpleTest/SimpleTest.js:417:16
[task 2021-01-26T13:06:41.977Z] 13:06:41 INFO - test_pointer_mouse_event@dom/events/test/pointerevents/test_pointermove_drag_scrollbar.html:60:5
[task 2021-01-26T13:06:41.977Z] 13:06:41 INFO - TEST-PASS | dom/events/test/pointerevents/test_pointermove_drag_scrollbar.html | should receive pointerup event
[task 2021-01-26T13:06:41.978Z] 13:06:41 INFO - TEST-PASS | dom/events/test/pointerevents/test_pointermove_drag_scrollbar.html | should receive mousedown event
[task 2021-01-26T13:06:41.978Z] 13:06:41 WARNING - TEST-UNEXPECTED-FAIL | dom/events/test/pointerevents/test_pointermove_drag_scrollbar.html | should not receive mousemove event
[task 2021-01-26T13:06:41.978Z] 13:06:41 INFO - SimpleTest.ok@SimpleTest/SimpleTest.js:417:16
[task 2021-01-26T13:06:41.978Z] 13:06:41 INFO - test_pointer_mouse_event@dom/events/test/pointerevents/test_pointermove_drag_scrollbar.html:65:5
[task 2021-01-26T13:06:41.978Z] 13:06:41 INFO - TEST-PASS | dom/events/test/pointerevents/test_pointermove_drag_scrollbar.html | should receive mouseup event"

Comment 4

[Edgar Chen [:edgar]]

https://treeherder.mozilla.org/#/jobs?repo=try&revision=50484397858d047736cd6094537ca664c439eba5

Comment 5

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/d2a9f662587b
Prevent dispatching pointermove events targeted at a slider frame to web content, if the scrollbar is being dragged; r=smaug

Comment 6

[Andreea Pavel [:apavel]]

https://hg.mozilla.org/mozilla-central/rev/d2a9f662587b