Check if library folders exist before exporting them

We get the STEAM_COMPAT_LIBRARY_PATHS variable from Steam itself, but
for some reason, Steam can pass library folders that no longer exist in
this variable.

When STL searches through the library folders when trying to set up some
Steam library path variables itself, a minor warning from \`find\` is
triggered in setSteamLibraryPaths. This should not cause any bugs, but
to prevent the output from the command line (which could also
potentially confuse users), add a check before continuing with the while
loop to ensure that the current path actually exists.

I noticed this when I replaced a drive in my PC and saw the warning from
find. Should not change any behaviour apart from cleaning up after what
appears to be an extremely minor Steam client bug.

steamtinkerlaunch

@@ -6,7 +6,7 @@
 PREFIX="/usr"
 PROGNAME="SteamTinkerLaunch"
 NICEPROGNAME="Steam Tinker Launch"
-PROGVERS="v12.12.20230314-1"
+PROGVERS="v12.12.20230314-2"
 PROGCMD="${0##*/}"
 SHOSTL="stl"
 GHURL="https://github.com"
@@ -1552,29 +1552,30 @@ function listSteamLibraries {
 	fi
 }
 
-# originally meant for debugging #508, but might be useful for an attempt to rewrite everything to be SLR compatible again...
-
 function setSteamLibraryPaths {
 	while read -r lpath; do
+		# Ignores library folders if they are not valid directories -- This var comes from Steam but apparently can still have invalid library folders.
+		# Noticed this when I removed a drive that had a Steam library folder, this didn't cause any major issues aside from a 'find' warning from the cmpath while loop - Could be a Steam bug?
+		if [ ! -d "$lpath" ]; then
+			writelog "WARN" "${FUNCNAME[0]} - Library folder '$lpath' does not seem to be a valid directory, even though this comes from Steam itself - Ignoring, but please report if this is invalid or causes issues"
+			continue
+		fi
+
 		if [ -z "$STEAM_COMPAT_LIBRARY_PATHS" ]; then
-			STEAM_COMPAT_LIBRARY_PATHS="$lpath"
+			STEAM_COMPAT_LIBRARY_PATHS="$lpath"  # This var should come from Steam, even the Proton script uses it
 		else
 			if ! grep -q "$lpath" <<< "$STEAM_COMPAT_LIBRARY_PATHS" ; then
 				STEAM_COMPAT_LIBRARY_PATHS="$STEAM_COMPAT_LIBRARY_PATHS:$lpath"
 			fi
 		fi
 
-# XXXXXXXXXXXX todo?:
-# remove Proton here and add it later when the used proton version is known for both variables
-# STEAM_COMPAT_TOOL_PATHS does not need STEWOS so maybe remove later
-
 		while read -r cmpath; do
 			if [ -n "$cmpath" ]; then
 				if [ -z "$STEAM_COMPAT_MOUNTS" ]; then
 					STEAM_COMPAT_MOUNTS="$cmpath"
 				else
 					if ! grep -q "$cmpath" <<< "$STEAM_COMPAT_MOUNTS" ; then
-					STEAM_COMPAT_MOUNTS="$STEAM_COMPAT_MOUNTS:$cmpath"
+						STEAM_COMPAT_MOUNTS="$STEAM_COMPAT_MOUNTS:$cmpath"
 					fi
 				fi
 
@@ -1621,7 +1622,6 @@ function listAppManifests {
 		fi
 	}
 
-
 	function listAllAppMas {
 		if [ -d "$DEFSTEAMAPPS" ]; then
 			findAppMa "$DEFSTEAMAPPS"
@@ -1670,12 +1670,9 @@ function pollWinRes {
 		SCREENRES="$(getScreenRes r)"
 	fi
 
-	if [ -z "$SCREENRES" ]; then
-		SCREENRES="any"
-	fi
+	if [ -z "$SCREENRES" ]; then  SCREENRES="any"; fi
 
-	# skip this if FIXGAMESCOPE is 1 - so for now only if running in GameMode on the Steam Deck
-	if [ "$FIXGAMESCOPE" -eq 0 ]; then
+	if [ "$FIXGAMESCOPE" -eq 0 ]; then  # skip this if FIXGAMESCOPE is 1 - so for now only if running in GameMode on the Steam Deck
 		TEMPL="template"
 		GAMEGUICFG="$STLGUIDIR/$SCREENRES/${AID}/${TITLE}.conf"
 		TEMPLGUICFG="$STLGUIDIR/$SCREENRES/${TEMPL}/${TITLE}.conf"