neoforge: handle new version ordering (#3703)

scripts/start-setupModpack

@@ -3,10 +3,8 @@
 set -e -o pipefail
 
 : "${REMOVE_OLD_MODS:=false}"
-: "${MODS:=}"
 : "${MODS_OUT_DIR:=/data/mods}"
 : "${MODS_FILE:=}"
-: "${PLUGINS:=}"
 : "${PLUGINS_OUT_DIR:=/data/plugins}"
 : "${PLUGINS_FILE:=}"
 : "${REMOVE_OLD_MODS_DEPTH:=1} "
@@ -94,7 +92,7 @@ fi
 
 function handleListings() {
   if usesMods && usesPlugins; then
-      if [[ "$MODS" ]]; then
+      if [[ -v MODS ]]; then
 
         ensureRemoveAllModsOff "MODS is set"
 
@@ -105,7 +103,7 @@ function handleListings() {
           --to="$MODS_OUT_DIR" \
           "$MODS"
       fi
-      if [[ "$PLUGINS" ]]; then
+      if [[ -v PLUGINS ]]; then
         ensureRemoveAllModsOff "PLUGINS is set"
         mkdir -p "$PLUGINS_OUT_DIR"
         mc-image-helper mcopy \
@@ -140,14 +138,14 @@ function handleListings() {
       outDir="$PLUGINS_OUT_DIR"
     fi
 
-    if [[ "$MODS" || "$PLUGINS" ]]; then
+    if [[ -v MODS || -v PLUGINS ]]; then
       ensureRemoveAllModsOff "MODS or PLUGINS is set"
       mkdir -p "$outDir"
       mc-image-helper mcopy \
         --glob=*.jar \
         --scope=var-list \
         --to="$outDir" \
-        "$MODS" "$PLUGINS"
+        "${MODS:-}" "${PLUGINS:-}"
     fi
 
     if [[ "$MODS_FILE" || "$PLUGINS_FILE" ]]; then