run.sh: Update SteamLaunch with a futureproof version

Author: arrowmaster

assets/nix/run.sh

@@ -67,12 +67,34 @@ corlib_dir=""
 
 # Special case: program is launched via Steam
 # In that case rerun the script via their bootstrapper to ensure Steam overlay works
-if [ "$2" = "SteamLaunch" ]; then
-    steam="$1 $2 $3 $4 $0 $5"
-    shift 5
-    $steam "$@"
-    exit
-fi
+for a in "$@"; do
+    case "$a" in
+        SteamLaunch)
+            rotated=0; max=$#
+            while [ $rotated -lt $max ]; do
+                case "$1" in
+                    *$executable_name)
+                        to_rotate=$(($# - rotated))
+                        set -- "$@" "$0"
+                        while [ $((to_rotate-=1)) -ge 0 ]; do
+                            set -- "$@" "$1"
+                            shift
+                        done
+                        exec "$@"
+                    ;;
+                    *)
+                        set -- "$@" "$1"
+                        shift
+                        rotated=$((rotated+1))
+                    ;;
+                esac
+            done
+            exit 1
+        ;;
+        *)
+        ;;
+    esac
+done
 
 # Handle first param being executable name
 if [ -x "$1" ] ; then