https://bugs.winehq.org/show_bug.cgi?id=48006
--- Comment #32 from Andrew Church achurch+wine@achurch.org --- The first common in Proton's wine-8.0 branch on which the launcher works correctly is:
https://github.com/ValveSoftware/wine/commit/2ef70f4daae6cd31b2b3f96c3b71b77...
The above commit alone (along with a number of prerequisite commits, see below) causes the launcher to crash on startup, and these commits are also required:
https://github.com/ValveSoftware/wine/commit/43d326b6807d5a9915622fa6e9a9b05...
https://github.com/ValveSoftware/wine/commit/52b574fad3658e4e47928df3510df64...
I've made a proof-of-concept branch (ff14-launcher-poc) at https://gitlab.winehq.org/achurch/wine with the above commits applied, including all other commits between wine-8.0 and proton HEAD which I needed in order to get Wine to build, applied on top of wine-8.13, which is the most recent version of Wine to which the commits applied reasonably cleanly; WCHAR->char changes in wine-8.14 (c81c0aa) conflict significantly with some of these commits. I imagine there's a smaller subset of changes which would suffice to fix the launcher, but I don't have enough (read: any at all) knowledge of the mshtml or jscript APIs to whittle it down beyond this. For the same reason, there are probably some bugs introduced from merging the Proton changes into more recent Wine (I haven't attempted to run the tests). Anyone with that knowledge is welcome to take this branch as a starting point.