'Use system theme' option in Dash to Dock breaks Ubuntu Dock theme on revert

[Ads20000]

To reproduce
------------
Enable Dash to Dock.
Go into its settings.
Set 'use system theme'.
Disable Dash to Dock (to revert to Ubuntu Dock).
It will be a completely solid darker colour and won't go transparent when you move windows away from it.

Expected behavior
-----------------
After enabling 'use system theme' and reverting to Ubuntu Dock, the Ubuntu Dock uses its usual theme (because it doesn't support the 'use system theme' setting).

[Ads20000 (ads20000)]

There seem to be other problems with enabling and then disabling Dash to Dock:

The active items on the dock have the orange underline rather than the orange dot
There's more padding between the items which wasn't there originally - the whole dock is thicker

[Ads20000 (ads20000)]

I wasn't able to use ubuntu-bug because I'm on extension version 0.7.1 from artful-proposed.

[Daniel van Vugt (vanvugt)]

Thank you for reporting this bug to Ubuntu.
Ubuntu 17.10 (artful) reached end-of-life on July 19, 2018.

See this document for currently supported Ubuntu releases:
https://wiki.ubuntu.com/Releases

We appreciate that this bug may be old and you might not be interested in discussing it any more. But if you are then please upgrade to the latest Ubuntu version and re-test. If you then find the bug is still present in the newer Ubuntu version, please add a comment here telling us which new version it is in.