Bug:thruspecies not working properly when on moving platform

[Jroc]

This is an issue I found when testing a new skulltag binary that backports the THRUSPECIES flag, which later turned out to be a zdoom bug. If you add +thruspecies to the doomplayer actor in decorate, when two players are on a platform and inside each other, when the platform raises one of the players will be forced on top of the other.

Quick way to reproduce:

Run this wad in zdoom http://www17.zippyshare.com/v/67445612/file.html (adds +THRUSPECIES to the doomplayer actor)
Spawn a doomplayer (summon doomplayer in console) on the lift in the main hall in Map01, go into chasecam and walk inside the doomplayer then observe what happens when the platform raises. Either you or the doomplayer will be forced on top of the other while it raises, however when the platform stops or lowers all is back to normal again.

[Gez]

It's not just THRUSPECIES. You'll get the same thing with any other THRU* flag, such as for example THRUACTORS. This reminds me of this but obviously that fix was not enough.

See this for a possible fix.