
The WAD "pollution" was being discussed over at Doomworld. However, there are 2 WADs and a dehacked patch in the zip so I put it together in a single WAD for my own use. However, when I went from map09 to map10, GZdoom dropped to the console with an error about the map. Fair enough if the map is broken. So, anyway, I quit so that I could check the map and fix it but when I did, there was a crash dialogue at the desktop.
If I use the following procedure, I can get a crash dialogue every time.
Load the WAD.
Start a game (I usually use HMP)
bring down the console
type map map09
type kill monsters
close the console
run forward into the teleport ahead
run across the big room to the doors that are opening on the far side
you will be teleported to a switch, use it
walk forward to exit the level
skip past the intermission kill tally
GZdoom should drop to the console with an error message
Quit by calling up the menu, selecting quit and pressing Y
If you do the above, there should be a crash dialogue generated. Missing out some of the steps can cause the crash not to happen.
Here is my copy of the consolidated WAD
http://www.rowand.myzen.co.uk/pollution.zip
and here is what I get with the debugger when I follow the above procedure.

Here's hoping it is related to the other crash, but I don't think so. Either way, it's still a crash.