https://bugs.winehq.org/show_bug.cgi?id=52024
--- Comment #8 from Zebediah Figura z.figura12@gmail.com --- Ah, sorry to step on your toes.
Since it's a socket-related regression, and since I did a bunch of socket-related changes in the past year which means it's almost certainly my fault, so I took the initiative and tried to debug it (which ended up being relatively easy even without knowing the exact regression commit).
Based on the fix I suspect the regression commit is c46ab05e55860. Debugging the rest is probably going to be hard.