1938158 - <select> menu-popups have a thin strip where :hover stops applying to select button

Status: NEW

(Core :: Layout: Form Controls, defect)

Description

[Daniel Holbert [:dholbert]]

STR:

1. Load attached testcase.
2. Click the button to open the <select> menu-popup.
3. Move your mouse off the bottom of the select menu-popup, and very slowly move your mouse inside the menu-popup to hover the last menu entry.

ACTUAL RESULTS:

• When your cursor starts to enter the menu-popup, the button gains hover-styling (turning blue)
• Then it briefly flashes back to its unhovered styling (turning orange)
• Then it flashes back to hover styling (turning orange)

EXPECTED RESULTS:
No such brief flicker/flash. Assuming we want the menu-popup to trigger hover styling on the button at all, it should do so consistently.

Comment 1

[Daniel Holbert [:dholbert]]

Attachment: testcase 1

Comment 2

[Daniel Holbert [:dholbert]]

Attachment: screencast of bug

Comment 3

[Daniel Holbert [:dholbert]]

Attachment: another screencast of bug

Here's a second screencast where I've zoomed in 500% to make the geometry slightly easier to see.

A few observations:

• As far as I can tell, it's not possible for me to pause my cursor on whatever the boundary/dead-sone is here. The flicker is always just a brief flicker, no matter how slowly I move my mouse (or how much I try to stop moving it in the dead-zone).
• The flicker of unhovered styling only happens as I move my cursor inwards, into the menu. If I move my mouse back outwards, there's no flicker (the hover styling isn't lost until I actually exit the menu-popup).

Comment 4

[Daniel Holbert [:dholbert]]

Attachment: screencast of bug on Windows

I can reproduce on Windows too; here's a screencast there. On Windows, the flicker seems to happen as I enter the popup as well as when I exit it.