Window Node Top bar doesn't reappear when Mode changed back to "Windowed" from "FullScreen"

[omarbassam88]

Godot version:

18c51d3

OS/device including version:

Linux POP OS 20.04 LTS Godot 4.0 with the Vulkan setup.

Issue description:

The New Window Node, when you change the mode from "Windowed" to "Fullscreen" it works fine. However, if you change it back to "Windowed", the top bar doesn't come back.

Steps to reproduce:

1. Add Window Node
2. Change the Mode from "Windowed" to "FullScreen".
3. Change it back again to "Windowed".

Minimal reproduction project:

[Rubonnek]

Are you using x11 or wayland?

[omarbassam88]

Are you using x11 or wayland?

I am on POP OS that uses X11.

[Rubonnek]

This seems to be a duplicate of #40037 -- could you try the borderless test there and see if the top bar doesn't come back?

This is also related to #40007 as toggling fullscreen changes the borderless value.

[omarbassam88]

I guess the Issues you mentioned are related to the Main window manager of the Editor and the settings in the Project settings. I was actually talking about the new "Window" Node presented in the new Godot 4.

Maybe they are related, or they are the same issue under the hood. I don't know.

[akien-mga]

I tested if this was still reproducible in current master (d29e17d) and it seems fixed.

Using this script:

extends Control

func _ready():
	$/root.gui_embed_subwindows = false
	
	var w = Window.new()
	w.title = "Hi"
	w.position = Vector2(200, 200)
	w.size = Vector2(300, 100)
	var l = Label.new()
	l.text = "I'm the subwindow"
	w.add_child(l)
	add_child(w)

	w.mode = Window.MODE_WINDOWED
	await get_tree().create_timer(2.0).timeout

	w.mode = Window.MODE_FULLSCREEN
	await get_tree().create_timer(2.0).timeout

	w.mode = Window.MODE_WINDOWED

Here's how it looks like on Mageia 9 KDE Plasma/KWin on X11:

simplescreenrecorder-2022-07-19_10.21.25.mp4

I do reproduce a situation where the window title bar disappears while being in windowed, but that's on the main window when setting fullscreen in project settings, which doesn't work properly (that's #54065).