1259357 - mouseup event target is wrong when the mousedown element is in overflow:hidden

Status: UNCONFIRMED

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

Description

[Jumper Chen]

User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.11; rv:44.0) Gecko/20100101 Firefox/44.0
Build ID: 20160210153822

Steps to reproduce:

1. Go to this example code - https://jsfiddle.net/crg1bhw8/
2. Mousedown into the green area and keep it
3. Move to the blue area to release your mouse (i.e. mouse up upon the blue area)



Actual results:

You will see the console log with "Please mouse down on me"


Expected results:

You should see the console log with "Please mouse up on me", this result works on all the latest browsers (IE8~11, Edge, Safari, and Chrome) except Firefox.

Comment 1

[Andrew Overholt [:overholt]]

Is this a dupe of bug 1257813?

Comment 2

[Jumper Chen]

No, this issue is related to the CSS "overflow:hidden", without it everything works well.

Comment 3

[Andrew Overholt [:overholt]]

Oh, then maybe a dupe of bug 1265237?

Comment 4

[Markus Stange [:mstange]]

Is this bug a regression? I'd be surprised if it was. My guess is that this is caused by the automatic mouse capturing that scrollable elements do, at https://dxr.mozilla.org/mozilla-central/rev/5511d54a3f172c1d68f98cc55dce4de1d0ba1b51/layout/generic/nsFrame.cpp#3260

Comment 6

[Dennis Schubert [:denschub]]

Attachment: Standalone testcase

I accidentally built a testcase for this while trying to debug a WebCompat issue. As the initial report is hosted on jsfiddle and might disappear some day, the simplified testcase is attached.

Comment 7

[Dennis Schubert [:denschub]]

Flagging for WebCompat prioritization, as this breaks a JS table script, see bug 1529753.

Comment 8

[Karl Dubost💡 :karlcow]

This is still an issue but there is no known site currently affected by this bug.

Comment 10

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

Redirect a needinfo that is pending on an inactive user to the triage owner.
:mccr8, since the bug has recent activity, could you have a look please?

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