The editor viewport with wrong size

[Geequlim]

Operating system or device - Godot version:
Godot 3.0 on Arch Linux - x86_64 compiled with 4286aef

Issue description:

The window size in project settings is 1024x600 but the viewport of the editor canvas seems to be 1294x815.

• The panel should be the same size as viewport.
• The viewport size is not same with the rectange drawing in the canvas.
• The viewport size may be changed by other nodes.
  
  

Steps to reproduce:

• Create a panel as the root node
• Set the size of the panel to be fill parent
• Zoom the canvas

[bojidar-bg]

Uhm. Sure it isn't a feature again?