Fellow Linux users, I ask for your help.
I've managed to get my chat to work after a day of tinkering with native Windows DLLs, .ini files and other stuff. After completely messing up my WINE, I reinstalled it, copied over LoL and the registry files, and to my complete surprise the chat now works.
The problem with my completely "scientific" method is that I've had trouble replicating the fix. At the moment, what seems to be causing the chat to work are my registry settings, which you can find here:
I'd like to ask you guys to replace your registry files (system.reg, user.reg and userdef.reg, found in ~/.wine/) with the my files, join a tutorial/practice game, try chatting and then let me know whether it works for you as well or not. Worse case scenario, I'll just create a 1.6 GB archive of my whole .wine directory and put that as a torrent, however I'd like to single out what's causing the chat to work.
Very important If you apply this fix, you'd be replacing your Registry with mine, which means that if you're using WINE for other software as well, it might stop working. Before replacing those three files, make sure you backup yours. Backing up your entire .wine folder might be even safer, although possibly overkill.
I am attaching a copy of my old registry files, so maybe you can compare the new to the old? This fix pretty much means all *gameplay* issues in the game are now solved (leaving just the store to be fixed). I'll try to compare both of the files too but I'm sure you'll better know what's up than myself.
PS: I love you.