1507516 - HTML select cut off on non-retina monitors using retina Macs

Status: UNCONFIRMED

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

Description

[Ben Thomas]

Attachment: issue.png

User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.14; rv:64.0) Gecko/20100101 Firefox/64.0

Steps to reproduce:

Note: This is all in the scenario where you have a Retina Mac, and a non-retina monitor plugged in to it.

1. Set FireFox to open on you non-retina monitor by default.
2. Have any generic HTML select with many options (e.g. 20) on a page.
3. Straight after the browser opens, load that page and click the select, it will display all of the results the first time only.
4. Click the select again after closing it, now it will only show a limited number of results (in my case, 10). If you have multiple selects on the same page, clicking on any of them will also result in the others being cut off.
5. Refreshing the page results in all long select boxes being cut off, even if you have not opened any of them previously.

Example HTML to reproduce this issue: https://codepen.io/anon/pen/MzmRwr

The options are still there even when not displayed, as you can use the keyboard down arrow then tab to select them.
If you move the browser to a Retina monitor, the selects are displayed correctly.

Tested on MacOS High Sierra 10.13.6 and Mojave 10.14/10.14.1.
Confirmed on FireFox Developer edition 64.0b9 (64-bit) and Firefox 63.0.1 (64-bit).


Actual results:

Select boxes are cut off after a number of results.


Expected results:

Selext boxes should not be cut off.

Comment 1

[Ben Thomas]

Note: Still the case as of FireFox Developer edition 65.0b8 (64-bit) and Firefox 64.0 (64-bit).

This also only seems to occur when using a non-retina monitor at it's native resolution - it does not happen if you use a scaled resolution lower than the native resolution; so I'm thinking perhaps it's a bug related to DPI scaling?

Comment 2

[Ben Thomas]

Still the case as of FireFox Developer edition 68.0b11 (64-bit) and Firefox 67.0.3 (64-bit).
Any chance of this being looked at please? There haven't been any updates from the Mozilla side in the 7 months since it was opened.

Comment 3

[Sean Voisen (:svoisen)]

Hi Ben – We are planning to do some form control maintenance and updates in the coming months, so we will have this on our radar as part of that work. Thanks for filing this.