[Affected versions]:

• Fx 75.0a1 (2020-02-13)
• Fx 74.0b2
• Fx 73.0

[Affected platforms]:

• Ubuntu 18.04

[Steps to reproduce]:

1. Go to any site
2. Click the Print option from File (Menu Bar)
3. Click on the Page Setup
4. Open the Paper size dropdown

[Expected result]:

• No additional space is displayed inside the dropdown

[Actual result]:

• Extra white space is displayed on top of the dropdown

[Regression range]:

• Reproducible on Fx 73.0a1 (2020-01-03); I will provide additional info asap.

[Additional notes]:

• Once the dropdown is scrolled all the way down and then up, the extra space disappears
• I can't see this issue on any other dropdowns from Page Setup

Anca, do you have an update on this bug? Is that a recent regression?

This issue is a regression, but an old one, I could narrow a regression window to the following:

• Last good revision: c321d84038519dcf1670d59fd2c5c00ad8a85a55 (2015-11-26)
• First bad revision: 47b49b0d32360fab04b11ff9120970979c426911 (2015-11-27)
• Pushlog:
  https://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=c321d84038519dcf1670d59fd2c5c00ad8a85a55&tochange=47b49b0d32360fab04b11ff9120970979c426911

Note that, while attempting to search the regression range, I couldn't reproduce this issue on every machine. I don't know what could trigger it, using two test machines with the same Ubuntu 18.04.4 (graphics AMD Rs780), I ended up reproducing it on one machine and not on the other. Also, the issue is reproducible with an Ubuntu 18.04.4 (graphics Intel HD Graphics 5500). If reproducible once, the issue is always reproducible on that test machine, with the provided steps on a clean or dirty profile.

If I can provide additional information let me know!

Thanks, given that this is an old regression, a potential fix could ride the trains.

The priority flag is not set for this bug.
:heycam, could you have a look please?

For more information, please visit auto_nag documentation.

The attached screencast appears to be broken (or incompatible with my system, at least) - could you try again to provide a screenshot of the issue? Thanks.

Huh, interesting. What was the current setting of the Paper Size option, before you clicked to open the menu? Normally, I'd expect the popup to appear with the current option aligned with the menu so that it starts out where the mouse is.

If you close the popup (but don't close the Print dialog) and then open it again, does it behave the same every time?

(In reply to Jonathan Kew (:jfkthame) from comment #7)

What was the current setting of the Paper Size option, before you clicked to open the menu?

• A4

If you close the popup (but don't close the Print dialog) and then open it again, does it behave the same every time?

• Yes, is the same behavior, the only way the space disappears (while the dropdown is opened) is when it is scrolled down until the extra space is no longer visible and then scrolled all the way up, but once I re-opened it, the issue reproduces all over again

• the white space is getting larger while scrolling down the dropdown, the image provided in comment 6 was took after scrolling a little bit down.

This is not an issue in our code. I can see the same issue on gedit on Ubuntu 18.04.