What about something like this?

Oh, and you are right again.
The previous solution seems to fix it without a regression, but obviously the code itself feels at the very least "not good".

Updated!
I didn't think about this solution, thanks, clearly it's way better than mine.

Ping

Yep, that's exactly what I did to fix that the first time I tried to write a patch!
The problem is, it doesn't solve it.
It will show the name of a folder wrong, if its url in places contains trailing slash (and it's easy to do, the patch that you linked still allows users to manually create/edit such urls in "places").
(The version which just always strips the trailing slash: https://i.imgur.com/QR0GGnx.png)

As far as I understand, nope, that commit just changes the url which is going to be added to "places".
Firstly, it doesn't fix the bug, and secondly, a user still can add/modify a url in places so that it contains a trailing slash, and current version of dolphin will show it's name wrong (if opened manually, as on the screenshots in "Test Plan").

Done

If this is not a desired default behavior, I'll need some hints on how to make a setting for it.

Thanks,