Adding to the ticket.
Installing a non-steam game to a path with spaces (example: Genshin Impact into Program Files) and then manually setting the launch executable to the GI launcher, results in having to add double-quotes at the start and end of the path manually in order for Steam to launch it. A workaround in this case is to install the launcher & game at the root of the WINE/Proton C: drive.
This could also be affecting the launch dir evaluation, but since the game can launch without in some cases, this is less testable.
Adding to this, other special characters such as ( are not escaped either.
I wish I had thought of the double quotes at the time, but I ended up with something like this to make Battle.net work on Steam: drive_c/Program\ Files\ \(x86\)/Battle.net/Battle.net.exe
Nothing extracted yet.
Your system information
Please describe your issue in as much detail as possible:
Expected: Diablo 2 launches after providing correct install paths.
Happens: Steam runs program
Diablowith argumentII.exehttps://gist.github.com/jakubbys/4586a502763dba0fa2e7c8fb15deb0b9
Steps for reproducing this issue:
Diablo II.exe)