Grenade smoke is stopped from spreading when in shouldn't

[MarkusRamikin]

Fences, low hedges, broken inner walls of a UFO, behave like solid walls in that they stop the smoke grenade's cloud from expanding. In the original game smoke spread as you'd expect, unimpeded by such terrain features.

[MarkusRamikin]

Also some types of urban floor tiles, apparently.

[katastic]

A quick glance at the smoke code, it looks like it uses the same code for explosions (just no call to a startfire/setfire function) with no provision/alteration for smoke. It's been two decades since I played legit xcom so I can't go on experience. Is there a screenshot or Lets Play video of this correct behavior?

[MeridianOXC]

In OG, smoke goes through everything, even solid UFO walls, buildings, etc.
I assume OpenXcom wanted to fix that.
Assigning to Warboy to clarify.
I personally would prefer if smoke was stopped by fences over smoke not being stopped by anything.