null instead of empty string

Author: ghzdude

src/main/java/gregtech/api/mui/sync/GTFluidSyncHandler.java

@@ -20,6 +20,7 @@
 import com.cleanroommc.modularui.value.DynamicValue;
 import com.cleanroommc.modularui.value.sync.SyncHandler;
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
 import java.util.function.BooleanSupplier;
 import java.util.function.Consumer;
@@ -154,13 +155,14 @@ public boolean showAmount() {
         return String.format("%,d", tankFluid == null ? 0 : tankFluid.amount);
     }
 
-    public @NotNull String getFluidLocalizedName() {
+    public @Nullable String getFluidLocalizedName() {
         var tankFluid = this.tank.getFluid();
+        var lockedFluid = this.lockedFluid.getValue();
 
-        if (tankFluid == null && getLockedFluid() != null)
-            return getLockedFluid().getLocalizedName();
+        if (tankFluid == null && lockedFluid != null)
+            return lockedFluid.getLocalizedName();
 
-        return tankFluid == null ? "" : tankFluid.getLocalizedName();
+        return tankFluid == null ? null : tankFluid.getLocalizedName();
     }
 
     @Override

src/main/java/gregtech/common/metatileentities/multi/multiblockpart/MetaTileEntityFluidHatch.java

@@ -272,7 +272,7 @@ public ModularPanel buildUI(PosGuiData guiData, PanelSyncManager guiSyncManager)
                         .textBuilder(richText -> {
                             richText.addLine(IKey.lang("gregtech.gui.fluid_amount"));
                             String name = fluidSyncHandler.getFluidLocalizedName();
-                            if (name.isEmpty()) return;
+                            if (name == null) return;
                             if (name.length() > 25) name = name.substring(0, 25) + "...";
 
                             richText.addLine(IKey.str(name));