1815370 - about:preferences "Default Font" menu gets unexpected text-selections inside of & around it, if you click and hold to open the menu

Status: VERIFIED FIXED

(Firefox :: Menus, defect, P1)

Description

[Daniel Holbert [:dholbert]]

STR:

1. Open Firefox preferences (about:preferences)
2. Type "font" into the search field
3. Left-click the dropdown menu for the default font, and do not release the mousebutton.
4. Still holding down your mouse button, move your mouse up and down to change the highlighted entry. Move it side to side as well.

ACTUAL RESULTS:
As you move the mouse up and down over the menu, various entries seem to have their text selected (though it's only certain entries that are selectable like this, for some reason -- it always seems to be the same ones).

If you move the mouse side to side, the adjacent text (the "Size" label and the "Advanced" button) get selected as well.

EXPECTED RESULTS:
No such text-selection, when my extended click is really just trying to pick an entry from the menu.

mozregression range:
https://hg.mozilla.org/integration/autoland/pushloghtml?fromchange=0c989b2bcd7882a9e7106e7879ab8933c2e09071&tochange=47c002d3637247e71ee901f32421deaecc9d8ea3
--> Regression from Bug 1805414

I can reproduce in latest Nightly on macOS and on Linux (Ubuntu 22.04, with Wayland)

Comment 1

[Daniel Holbert [:dholbert]]

Attachment: screencast

Comment 2

[BugBot [:suhaib / :marco]]

Set release status flags based on info from the regressing bug 1805414

:emilio, since you are the author of the regressor, bug 1805414, could you take a look? Also, could you set the severity field?

For more information, please visit auto_nag documentation.

Comment 3

[Emilio Cobos Álvarez [:emilio]]

Attachment: Bug 1815370 - Change XUL's user-select set-up to just specify it once. r=dholbert,dao,Gijs

user-select has used-value-time pseudo-inheritance1, so specifying it
on the root should be enough to make it work everywhere it matters.
Specifying it on all elements is somewhat inefficient.

We only had a handful of overrides2 so I think this is relatively
safe. This would only be a behavior change for pages with html roots but
also XUL inside (in which case some XUL could become selectable). We
don't seem to have many looking at 3 (the important one being
browser.xhtml, which is adjusted here).

Remove useless overrides (including search-textbox, since the input it
contains is always selectable anyways), and it only has the input and a
couple icons.

Comment 4

[Emilio Cobos Álvarez [:emilio]]

Attachment: Bug 1815370 - Tweak user-select setup in about:preferences to make menulists non-selectable. r=Gijs,dao

They weren't selectable before, by virtue of being a XUL frame, but that
was pure luck.

Depends on D169166

Comment 6

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/ea1678d5f738
Change XUL's user-select set-up to just specify it once. r=Gijs
https://hg.mozilla.org/integration/autoland/rev/f3989d95c89a
Tweak user-select setup in about:preferences to make menulists non-selectable. r=Gijs,settings-reviewers

Comment 7

[Serban Stanca [:SerbanS]]

https://hg.mozilla.org/mozilla-central/rev/ea1678d5f738
https://hg.mozilla.org/mozilla-central/rev/f3989d95c89a

Comment 8

[BugBot [:suhaib / :marco]]

The patch landed in nightly and beta is affected.
:emilio, is this bug important enough to require an uplift?

• If yes, please nominate the patch for beta approval.
• If no, please set status-firefox111 to wontfix.

For more information, please visit auto_nag documentation.

Comment 9

[Emilio Cobos Álvarez [:emilio]]

I believe this is rather risky to uplift.

Comment 10

[Ardelean Oana, Desktop Test Engineering [:oardelean]]

Reproducible with a 2023-02-12 Nightly build on macOS 12.
Verified as fixed on Firefox 112.0b2(build ID: 20230314181505) and Nightly 113.0a1(build ID: 20230315092641) on macOS 12, Windows 10, Ubuntu 22.