Editing hidden panels: the red line showing which panel is at issue seems too thin to be usable

[LinuxOnTheDesktop]

 * Cinnamon version (cinnamon --version) 4.0.10
   - Please specify if you are using the daily builds PPA (https://launchpad.net/~linuxmint-daily-build-team/+archive/ubuntu/daily-builds). No.
 * Distribution - (Mint 17.2, Arch, Fedora 25, etc...) 19.1
 * Graphics hardware *and* driver used: Intel UHD Graphics 620; 3.0 Mesa 18
 * 32 or 64 bit: 64
 * Attach /home/<username>/.xsession-errors, or /var/log/syslog

Issue

When using the panel configuration window (pictured below), and where the panel in question is hidden (set to auto-hide), a thin red line indicates which panel is being edited.

The line appears at the screen edge where the panel appears. On my system, with three hidden panels, this line is very hard to see and hence I cannot know which panel I am editing.

I am not managing to capture the red line in screenshots, for some reason.

Steps to reproduce

Have three hidden panels. Try to edit one of them.

Expected behaviour

A more visible indication of which panel is being edited. A thicker line - three times as thick, perhaps? - would do it.

Other information

[JosephMcc]

The proper solution would probably be to just unhide the panel when it's being edited.

[itzexor]

This change makes it just show briefly when it is initially highlighted, which is the best solution I can think of. Changing the width of the hidden panel would complicate the clipping and tweening code, and always showing it would prevent testing of autohide settings.

[LinuxOnTheDesktop]

Excellent - though I don't think the change has readed the main or even the alpha Cinnamon (the PPA) yet.

This problem seems of a similar sort.

[Odyseus]

Hello, everybody.

@LinuxOnTheDesktop: Look at the reference just above itzexor message. The fix hasn't been merged yet.