[1.8.4] Bug : ZDoom map wall switch doesn't work in Linux

[eefano]

On some recent ZDoom-compatible PWADs i have experienced this bug:
pressing some wall switches doesn't do anything (no wall animation, no sound, no events triggered)

The bug appears only under Linux (32 or 64 bit, it doesn't matter).
All of these versions show the same behaviour:
- binary from your debian repository (1.8.4)
- latest GIT clone
- GIT clone of the tag 1.8.2

The maps play all correctly under stable Windows binary (1.8.2)

To replicate easily this behaviour load up this WAD:
http://www.wad-archive.com/wad/57ca9057 ... 38d3e68428

- Start in MAP01
- IDDQD
- IDKFA
- From the starting point, follow the wall on your right
- around the corner you will find a Blue Door: open it
- try to push the skull button
- nothing happens in linux, button activates in windows.

Thank you

[Graf Zahl]

This will need some input from a Linux user.
I guess it's some compiler related problem.

[_mental_]

Check Compatibility Mode in Options -> Compatibility Options menu.
I was able to replicate the bug with the mode set to Doom instead of Default.

[Enjay]

I was about to test this then I saw that it was yet another WAD that has been uploaded uncompressed. 36MB? Very big for a Doom mod. I bet it compresses down quite a bit smaller than that. Either that or it's stuffed full of MP3s.

Zip up your WADs people.

[Graf Zahl]

Check Compatibility Mode in Options -> Compatibility Options menu.
I was able to replicate the bug with the mode set to Doom instead of Default.

Thanks. And having a closer look at the map shows a second door line being in front of the key, and with the compatibility option on it will block the switch behind.

Here's one very important tidbit:

If you play Boom maps with Doom.exe compatibility settings, things will break!
The engines have some different properties, with Boom a lot more forgiving.

Obviously, this is not a bug. The compatiblity option causing this behavior is there precisely to block uses through special lines.

[Enjay]

Is the line in question flagged as "use through"? If so, Boom is not just more forgiving in this particular case. Allowing switches to work when there are other activatable lines in front of them with the usethrough flag is a Boom design decision. It was done to allow switches that apparently allow more than one action on a single switch.

"Back in the day", while mapping specifically for Boom, I made a few switches like this but, of course, in game it's actually quite easy to break (e.g. you could be close enough to activate one line but not the one behind it).

[Graf Zahl]

I never checked, but the rule still stands:

Compatibility options are not there to get 'the original behavior' back.
They are there to re-enable bad engine code so that old maps work as intended.
Since the mod was only available as WAD I have no idea what requirements it sets.
But regardless, it does use Boom features which by definition means that the 'Doom.exe' compatibility profile is not the correct one.

[Enjay]

But regardless, it does use Boom features which by definition means that the 'Doom.exe' compatibility profile is not the correct one.

Oh, fully agreed. I was just trying to say that this might have been an intentionally used Boom feature rather than Boom simply being more forgiving (thereby further underlining that doom.exe compat is inappropriate).

[eefano]

Thank you for the clear explanation, now i have got it working and i have understood the expected behaviour of the compatibility modes.

Thanks again to Graf, Enjay and _mental_, you are truly dedicated and helpful!