Fix for SDL2 mouse scroll wheel bugs in Linux

[NukemD]

There seems to be an issue with the scroll wheel on Half-Life, and by extension, mods of Half-Life (TFC, CS, NS, etc.) where scrolling the wheel in either direction will erratically trigger +attack and +attack2 (and sometimes +attack3 on mods that support it), and even the mouse3 input. This can happen whether or not you have mwheelup, mwheeldown or mouse3 bound to anything.

I did a bit of digging and found that the mouse wheel having erratic behavior was apparently a known SDL2 input bug back in 2013-2014, but it was apparently patched, so I was confused as to why it is still happening. Digging further, I notice that Half-Life had its own copy of libSDL2-2.0.so.0 that appears to be an ancient version before those patches were applied upstream and pushed down the grape vine.

So as an experiment, I removed libSDL2-2.0.so.0 in the /.steam/steamapps/common/Half-Life/ directory and replaced it with a symlink to the system's own /usr/lib/libSDL2-2.0.so.0, and lo and behold the mouse starts working perfectly.

I'm assuming the lib is included in the Half-Life directory for compatibility reasons to prevent dependency hell. Would it be possible for the version of libSDL2-2.0.so.0 included with Half-Life be updated to the most recent release? It seems to be an issue across multiple Linux distros. I'm running Fedora 33, but I also tried it on OpenSUSE and Debian and had the same erratic mouse issues until I replaced the offending lib with the much more recent version.

[Idiot64]

i think you dont even have to create a symlink i'm not sure

[NukemD]

You can't leave it out because the next time the game updates or does a file integrity check, it'll download the old version of the file again.

[ArijanJ]

This still happens after the update, but now it presses random keys. Using distro's SDL instead works fine.

[NukemD]

Yep, Valve never fixed it. There are actually more dependency issues on the server side that break mods and Metamod plugins.