1353249 - [e10s] select - options styling doesn't work properly if CSS selector :hover is present

Status: NEW

(Core :: Layout: Form Controls, defect, P3)

Description

[684sigma]

Attachment: options styling doesn't work (CSS selector hover), by reporter.html

I noticed a problem in Nightly 55 (found in Video Download Helper extension). It doesn't happen in ESR 45.
:hover selector in CSS don't always styles options in <select> drop-down properly.
There're three ways to reproduce the bug.


First:
1. Open attached page
2. Click on <select> and move mouse away

Result: First, second, fourth, fifth options contain red text on pink background.
Expected: Should contain black text on white background.


Second:
1. Open attached page
2. Press Tab to focus <select>, press F4 to open <select>
3. Hover mouse over the fifth option

Result: First four options contain black text on white background.
Expected: Should contain red text on pink background.


Third:
1. Open attached page
2. Click on <select>
3. Hover mouse over the first option

Result: Last four options contain red text on pink background
Expected: Should contain blue text on lightblue background

Comment 1

[684sigma]

Tested on Nightly 2017-04-03, User Agent Mozilla/5.0 (Windows NT 6.1; WOW64; rv:55.0) Gecko/20100101 Firefox/55.0

Comment 2

[Mats Palmgren (inactive)]

> First:
> 1. Open attached page
> 2. Click on <select> and move mouse away
> Result: First, second, fourth, fifth options contain red text on pink background.

That's not the result I see in a current Nightly on Linux.
I see: the <select> and all <option>s have default styling
(with or without e10s enabled)

There *is* a bug with e10s enabled though -- just after the <select> is clicked
(before the "move mouse away" step) it should render the <option>s in the dropdown
menu in pink/red colors per the "select:hover option" rule.  It does not.
(That part works in non-e10s mode though.)

> Expected: Should contain black text on white background.

It's debatable whether that's the desired rendering.  It's what Chrome does,
but that might just be a bug in Chrome.  I don't see why the :hover rules
should apply when the mouse is outside all parts of the select/options.

Comment 3

[Sylvestre Ledru [:Sylvestre]]

Moving to p3 because no activity for at least 1 year(s).
See https://github.com/mozilla/bug-handling/blob/master/policy/triage-bugzilla.md#how-do-you-triage for more information

Comment 4

[Firefox Bug Husbandry Bot]

See bug 1547409. Moving webcompat whiteboard tags to project flags.