Ghost selection when working with several tabs

[maoschanz]

Description

data stored in the selection buffer might not be displayed in a few specific scenarii, misleading the user into thinking it's lost

Steps to reproduce the bug

1. previewing a transformation of the selection
2. opening a new image (ctrl+t)
3. changing the active tool to a tool which isn't a selection tool, nor another transformation tool (eg the pencil)
4. coming back to the initial image

result:

• it keeps the pencil as the active tool window-wide, which includes the tab of the initially edited image (correct?)
• it doesn't deselect the area (correct? incorrect?)
  • but the app doesn't know how to handle the selection buffer when the tool is the pencil, so it displays a transparent area missing pixels, as if the data was lost
  • yet the data is not lost, if you enable a selection tool it's displayed again (correct)
  • but the transformation has been cancelled (incorrect?)

System

• Device (desktop computer/tablet/phone/...): any
• OS: any
• Desktop environment: any
• Package format: any
• App version: 1.1.x