1424059 - [Fullscreen] If you drag and drop a Tab into the window, a large dark gap appears at the bottom of the page

Status: NEW

(Core :: Widget, defect, P3)

Description

[Mehmet]

Attachment: gap_fullscreen.mov

macOS 10.12.6
59.0a1 (2017-12-07) (64-Bit)

STR:

1.) Open a window
2.) Go into Fullscreen with SHIFT-CMD-F
3.) Be sure, that only one tab is in the Tab Bar
4.) Drag and drop this tab into the window's content

Actual: A large dark gap appears at the bottom of the page.

Expected: No gap.

A screencast is attached.

Comment 1

[Flore Allemandou [:flore]]

I can't reproduce that on latest nightly and Mac OS 10.13.1
Does it happen with a new profile ?

Comment 2

[Stephen A Pohl [:spohl]]

(see question in comment 1)

Comment 3

[Mehmet]

(In reply to Flore Allemandou [:flore] from comment #1)
> I can't reproduce that on latest nightly and Mac OS 10.13.1
> Does it happen with a new profile ?

I can reproduce it on 2 different devices with a new Profile: MacBook Air 11" and iMac 21,5". Both devices are from 2012 and have a Non-Retina screen.

Comment 4

[Stephen A Pohl [:spohl]]

I'm able to reproduce. The gap is exactly the height of the Dock. This can be verified by changing the size of the Dock.

Comment 5

[Mehmet]

(In reply to Stephen A Pohl [:spohl] from comment #4)
> I'm able to reproduce. The gap is exactly the height of the Dock. This can
> be verified by changing the size of the Dock.

Exactly! Thank you for confirming it.

Comment 6

[Flore Allemandou [:flore]]

That's why I could not reproduce: my dock is on the left side of the screen

Comment 7

[Mehmet]

(In reply to Flore Allemandou [:flore] from comment #6)
> That's why I could not reproduce: my dock is on the left side of the screen

It also happens, when the Dock is attached to the left or right side of the screen. Important is, that the "Hide Dock" Setting is *not* enabled.

If you don't noticing the issue, then I think, you have the "Hide Dock" setting enabled. If you take a closer look, then you'll see that the gap will be marginal in this case.

Comment 8

[Marius Coman [:mcoman], Ecosystem QA]

User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.12; rv:57.0) Gecko/20100101 Firefox/57.0
Firefox: 57.0.1, Build ID 20171128222554

I have managed to reproduce the issue on Mac 10.12, with Firefox release (57.0.1) and latest Nightly build (59.0a1). The issue is also reproducible on a new profile or with the safe mode activated. 

I've also encountered this issue on Windows 10 x64, but with a different behavior. After following the provided STR, the taskbar is display instead of the "dark gap" and and the Firefox toolbar is no longer displayed even if you hover the top part of the window. Here is a screen recording of the issue: https://goo.gl/XRF3yX.

The issue is also reproducible on Linux, but only if the launcher is displayed on the bottom of the screen (e.g. Archlinux 4.12). After following the STR, instead of the "dark gap", the footer of the page remains "stuck", even if you navigate to a different page. Here is a screen recording of the issue: https://goo.gl/YnEfZR.

I don't think that this issue is a regression since I've went back until Firefox 15 and the issue is still reproducible.
Considering this I will assign a component to this issue, in order to get the engineering team's opinion.