ID 370947 - Pinned layer stack palettes are not hidden when pressing spacebar

Problem summary
In Mari spacebar can be used to maximize a palette or for example to hide all palettes temporarily for full screen viewport.
Pinned layer stack palettes do not work the same way and are not temporarily hidden when pressing spacebar, rather they remain open.

Customer reported version

Customer reported platform

Steps to reproduce

1) Open the default head example project

2) Go to Channels palette and click on one of the channels 'layer stack' icon. A floating layer stack palette will appear.

3) Grab the floating panel and dock it 

4) With the cursor over the viewport, press space. All palettes disappear except the docked one.

5) Close any docked layer stack palettes and press space over the viewport. The remaining palettes are hidden as expected, until the next time spacebar is pressed.  

Workaround
Unknown. 

Reproduced by support

This bug has been reproduced in:

Mari 4.2v1 - Windows 10 - CentOS 7
Mari 4.1v1 - Windows 10
Mari 4.0v1 - Windows 10
Mari 3.4v1 - Windows 10 - CentOS 7 - unable to reproduce

Earliest version tested

Mari 3.4v1 - The functionality did not exist in this or earlier versions

Expected behaviour

Pinned layer stack palettes should be hidden when pressing spacebar, and restored when space is hit again.

Actual behaviour

Pinned layer stack palettes always stay open.