One-Time Run: Default to per-game Proton version if '--proton' is not…

… passed

If per-game Proton 'USEPROTON' is empty, we resolve the mismatch using that instead of RUNOTPROTON.
Also fixes an issue where One-Time Run did not correctly resolve Proton version mismatches if
RUNOTPROTON was blank.

steamtinkerlaunch

@@ -12225,6 +12225,7 @@ function OneTimeRunReset {
 
 # Called when a user passes arguments for onetimerun
 # TODO a way to use default game Proton version, either if '--proton' is not supplied or if '--proton="default"'?
+# TODO add a way to use PROTON_LOG with custom command?
 function commandlineOneTimeRun {
 	setOneTimeRunVars "$1"
 	# Get incoming arguments
@@ -12302,9 +12303,24 @@ function commandlineOneTimeRun {
 					return
 				fi
 				writelog "INFO" "${FUNCNAME[0]} - Trying to find Proton version to launch executable with from given Proton name '$RUNOTPROTON'"
+
+				# If user did not pass '--proton', then use the game's Proton version
+				if [ -z "$RUNOTPROTON" ]; then
+					writelog "INFO" "${FUNCNAME[0]} - Did not get RUNOTPROTON from '--proton' option (perhaps this option was omitted?), so using per-game Proton version (USEPROTON) '$USEPROTON'"
+					RUNOTPROTON="$USEPROTON"
+				fi
+
+				# TODO does OTPROTON need updated after a Proton version mismatch resolution?
 				RUNOTPROTON="$(getProtPathFromCSV "$RUNOTPROTON")"
 				if [ ! -f "$RUNOTPROTON" ]; then
-					RUNOTPROTON="$(fixProtonVersionMismatch "OTPROTON" "$STLGAMECFG" X)"  # TODO re-check to make sure this is valid?
+					writelog "INFO" "${FUNCNAME[0]} - RUNOTPROTON '$RUNOTPROTON' could not be found in ProtonCSV -- Attempting to resolve mismatch"
+					# "1" forces fixProtonVersionMismatch to run even though ISGAME != 2 (ISGAME -eq 2 means Proton game, but ISGAME may not be 2 for One-Time Run, so we force Proton version resolution)
+					if [ -n "$RUNOTPROTON" ]; then
+						RUNOTPROTON="$(fixProtonVersionMismatch "RUNOTPROTON" "$STLGAMECFG" "1" X)"
+					else
+						writelog "INFO" "${FUNCNAME[0]} - Attemptiing to resolve Proton version mismatch for blank RUNOTPROTON '$RUNOTPROTON' by instead trying to resolve based on USEPROTON '$USEPROTON' which should hopefully not be blank"
+						RUNOTPROTON="$(fixProtonVersionMismatch "USEPROTON" "$STLGAMECFG" "1" X)"
+					fi
 				fi
 			else
 				writelog "INFO" "${FUNCNAME[0]} - Given executable detected as native Linux binary, this is usually correct but if this was detected incorrectly you should force Proton!"
@@ -19351,7 +19367,8 @@ function getProtonDBRating {
 }
 
 function fixProtonVersionMismatch {
-	if [ "$ISGAME" -eq 2 ]; then
+	FORCEPROTONMISMATCHRESOLVE="${3:-0}"  # I.e. passed by One-Time Run where "ISGAME -eq 3"
+	if [ "$ISGAME" -eq 2 ] || [ "$FORCEPROTONMISMATCHRESOLVE" -eq 1 ]; then
 		ORGPROTCAT="$1"
 		MIMAPROT="${!1}"