1761839 - Clicking on a dialog backdrop selects everything inside the dialog

Status: VERIFIED FIXED

(Core :: DOM: Core & HTML, defect)

Description

[hi]

Steps to reproduce:

Create a <dialog> and use the .showModal() method to open it. When it is open, click anywhere on the backdrop (anywhere outside the dialog itself).

Actual results:

When you click on the backdrop, it causes everything inside the dialog to be selected.

Example here: https://codepen.io/kevinpowell/pen/ZEvKgyN

Expected results:

Clicking outside the dialog itself should result in nothing happening.

You can force this by declaring ::backdrop { pointer-events: none } in CSS, but that shouldn't be required.

Comment 1

[Alice0775 White]

I can reproduce the issue in Nightly100.0a1 Wundows10.
And I can also reproduce the issue in 91.7esr when set dom.dialog_element.enabled to true.

Comment 2

[Emilio Cobos Álvarez [:emilio]]

Attachment: Bug 1761839 - Prevent undesired interactions between backdrop and selection. r=sefeng

Our selection code doesn't deal too well with pseudo frames in the top
layer. This prevents the bad interaction.

Comment 3

[Emilio Cobos Álvarez [:emilio]]

Attachment: Bug 1761839 - Allow user-select: none to override modal dialog selectability. r=sefeng

Instead of enforcing it in C++ use a UA rule instead, so that authors
can override it if needed.

Depends on D142582

Comment 4

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/ad790a1f6c5f
Prevent undesired interactions between backdrop and selection. r=sefeng
https://hg.mozilla.org/integration/autoland/rev/bb6c65e9df92
Allow user-select: none to override modal dialog selectability. r=sefeng

Comment 5

[Web Platform Test Sync Bot [:wpt-sync] (Matrix: #interop:mozilla.org)]

Created web-platform-tests PR https://github.com/web-platform-tests/wpt/pull/33459 for changes under testing/web-platform/tests

Comment 6

[Web Platform Test Sync Bot [:wpt-sync] (Matrix: #interop:mozilla.org)]

Upstream PR merged by moz-wptsync-bot

Comment 7

[Natalia Csoregi [:nataliaCs]]

https://hg.mozilla.org/mozilla-central/rev/ad790a1f6c5f
https://hg.mozilla.org/mozilla-central/rev/bb6c65e9df92

Comment 8

[Monica Chiorean]

I was able to reproduce the issue without the fix on Ubuntu 20.4 using build 100.0a1(20220330214842)
Verified as fixed on Ubuntu20.4/ Mac 10.13/ Win10 using build 100.0b5(20220412185818).