getfileattributesexw_detour refactor + Linux Wine fix

[modestimpala]

Linux Wine / Proton Fix

I was able to confirm and reproduce the panic from unreal-shimloader versions 1.0.8+

I tracked this down to a test bug and resolved it by updating my Rust Nightly installation.

No longer encountered issue on the following version:

rustc --version --verbose
rustc 1.88.0-nightly (38c560ae6 2025-04-15)
binary: rustc
commit-hash: 38c560ae681d5c0d3fd615eaedc537a282fb1086
commit-date: 2025-04-15
host: x86_64-pc-windows-msvc
release: 1.88.0-nightly
LLVM version: 20.1.2

getfileattributesexw_detour refactor

However, this led me to a new bug forwarded to UE4SS from an issue in the getfileattributesexw_detour function:

UE4SS.log
[2025-04-17 01:03:46] Fatal Error: exists: Insufficient buffer.: "Z:\home\moddy\Games\pa082b_0016\WindowsNoEditor\VotV\Binaries\Win64\Mods\ActorDumperMod\dlls"

This is actually a GetFileAttributesExW call, for what appears to be an existence check.

shimloader-log.txt
[2025-04-16 18:03:46.582 DEBUG src\hooks.rs:284] [getfileattributesexw_detour] "Z:\\home\\moddy\\Games\\pa082b_0016\\WindowsNoEditor\\VotV\\Binaries\\Win64\\Mods\\ActorDumperMod\\dlls" to "C:\\users\\moddy\\AppData\\Roaming\\r2modmanPlus-local\\VotV\\profiles\\Default\\shimloader\\mod\\ActorDumperMod\\dlls"

I confirmed this directory does not exist. So it seems when UE4SS attempts to check if a non-existent directory exists, it encounters an "Insufficient buffer" error from the reroutes and it causes UE4SS to halt.

Changes

• Added an early existence check using GetFileAttributesW before attempting to call GetFileAttributesExW
• Return early with the appropriate error code if the file/directory doesn't exist
• Simplified a bit by removing some variable assignment/debug logging

Testing

• Verified functionality works correctly on both Windows and Linux (via Proton)

Linux info:

uname -r
6.14.2-arch1-1

wine-ge-8-26-x86_64 added to Lutris via ProtonUp-Qt.

Installed R2Modman via .exe installer and Lutris automated installer prompts, then set up as you normally would for modding operations. First launch should install C++ Redist for VotV then it's good to go.

Also, if you wanted to float one final DLL my way to test on my Linux setup just let me know.