From ceed457393424902accbd42c000cd958a5566a80 Mon Sep 17 00:00:00 2001
From: Phiality <155454343+PhialsBasement@users.noreply.github.com>
Date: Sun, 24 May 2026 19:10:06 +1000
Subject: [PATCH 1/2] belauncher: Prepend install path for game_exe starting
 with backslash.

PathIsRelativeW() returns FALSE for paths with a leading backslash, so a 64BitExe= entry like "\Game\Binaries\Win64\Game.exe" skipped the install-path prefix in launch_cmd. CreateProcessW then resolved it against the root of the current drive instead of the install directory, yielding ERROR_FILE_NOT_FOUND.

Fixes games like Contractors Showdown (VR), which have opted in to allow linux but have such config
---
 programs/belauncher/main.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/programs/belauncher/main.c b/programs/belauncher/main.c
index a2b0666ad916..dce94706508b 100644
--- a/programs/belauncher/main.c
+++ b/programs/belauncher/main.c
@@ -169,7 +169,7 @@ int WINAPI wWinMain(HINSTANCE hInst, HINSTANCE hPrevInst, LPWSTR cmdline, int cm
     battleye_status = 0x9; /* Launching Game */
     _write(1, &battleye_status, 1);
 
-    if (PathIsRelativeW(game_exeW))
+    if (PathIsRelativeW(game_exeW) || game_exeW[0] == L'\\')
         path_len = wcslen(path);
     else
         path_len = 0;

From 9ae91244cdba30b34f768505d116f0cade346b41 Mon Sep 17 00:00:00 2001
From: Phiality <155454343+PhialsBasement@users.noreply.github.com>
Date: Mon, 25 May 2026 04:40:29 +1000
Subject: [PATCH 2/2] belauncher: Fix handling of leading backslash in game
 executable path

Handle leading backslash for Windows BattlEye game executable paths.
---
 programs/belauncher/main.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/programs/belauncher/main.c b/programs/belauncher/main.c
index dce94706508b..0e9fea966a8f 100644
--- a/programs/belauncher/main.c
+++ b/programs/belauncher/main.c
@@ -169,7 +169,16 @@ int WINAPI wWinMain(HINSTANCE hInst, HINSTANCE hPrevInst, LPWSTR cmdline, int cm
     battleye_status = 0x9; /* Launching Game */
     _write(1, &battleye_status, 1);
 
-    if (PathIsRelativeW(game_exeW) || game_exeW[0] == L'\\')
+    /* Windows BattlEye treats a singleton leading-backslash 64BitExe as
+     * install-relative; strip it so the joined launch_cmd doesn't end up
+     * with a doubled separator.  Skip if a second '\' follows so UNC paths
+     * are preserved. */
+    if (game_exeW[0] == L'\\' && game_exeW[1] != L'\\')
+    {
+        memmove(game_exeW, game_exeW + 1, game_exe_len * sizeof(*game_exeW));
+        --game_exe_len;
+    }
+    if (PathIsRelativeW(game_exeW))
         path_len = wcslen(path);
     else
         path_len = 0;