123.1 Tunnel portal not displayed in underground mode when overbuild

[Flemmbrav]

Looks like this:


Basically, the way you build last, lasts here.
Which just doesn't look right at the end of a tunnel, as the portal isn't displayed that way.

This visual bug only happens in underground mode.

[prissi]

In tests in never showed a portal in the away facing end. I could not generate something like you showed.