Fix inventory renaming error.

src/main/java/ch/njol/skript/expressions/ExprNamed.java

@@ -18,6 +18,8 @@
  */
 package ch.njol.skript.expressions;
 
+import ch.njol.skript.lang.Literal;
+import ch.njol.skript.util.Utils;
 import org.bukkit.Bukkit;
 import org.bukkit.event.Event;
 import org.bukkit.event.inventory.InventoryType;
@@ -59,27 +61,51 @@ public class ExprNamed extends PropertyExpression<Object, Object> {
 	@SuppressWarnings("null")
 	private Expression<String> name;
 
-	@SuppressWarnings({"unchecked", "null"})
 	@Override
-	public boolean init(final Expression<?>[] exprs, final int matchedPattern, final Kleenean isDelayed, final ParseResult parseResult) {
-		setExpr(exprs[0]);
+	@SuppressWarnings("unchecked")
+	public boolean init(Expression<?>[] exprs, int matchedPattern, Kleenean isDelayed, ParseResult parseResult) {
+		if (exprs[0].getReturnType().equals(ItemStack.class)) {
+			setExpr(exprs[0].getConvertedExpression(ItemType.class));
+		} else {
+			setExpr(exprs[0]);
+		}
 		name = (Expression<String>) exprs[1];
+		if (getExpr() instanceof Literal) {
+			Literal<?> literal = (Literal<?>) getExpr();
+			Object object = literal.getSingle();
+			if (object instanceof InventoryType && !isCreatable((InventoryType) object)) {
+				Skript.error(Utils.A(literal.toString()) + " cannot be created.");
+				return false;
+			}
+		}
 		return true;
 	}
 
 	@Override
-	protected Object[] get(final Event e, final Object[] source) {
-		String name = this.name.getSingle(e);
+	protected Object[] get(final Event event, final Object[] source) {
+		String name = this.name.getSingle(event);
 		if (name == null)
-			return get(source, obj -> obj); // No name provided, do nothing
+			return get(source, object -> {
+				if (object instanceof InventoryType) {
+					InventoryType type = (InventoryType) object;
+					if (!isCreatable(type))
+						return null;
+					return Bukkit.createInventory(null, type);
+				}
+				return object; // Return the same ItemType they passed without applying a name.
+			});
 		return get(source, new Getter<Object, Object>() {
 			@Override
 			@Nullable
-			public Object get(Object obj) {
-				if (obj instanceof InventoryType)
-					return Bukkit.createInventory(null, (InventoryType) obj, name);
-				if (obj instanceof ItemStack) {
-					ItemStack stack = (ItemStack) obj;
+			public Object get(Object object) {
+				if (object instanceof InventoryType) {
+					InventoryType type = (InventoryType) object;
+					if (!isCreatable(type))
+						return null;
+					return Bukkit.createInventory(null, type, name);
+				}
+				if (object instanceof ItemStack) {
+					ItemStack stack = (ItemStack) object;
 					stack = stack.clone();
 					ItemMeta meta = stack.getItemMeta();
 					if (meta != null) {
@@ -88,7 +114,7 @@ public Object get(Object obj) {
 					}
 					return new ItemType(stack);
 				}
-				ItemType item = (ItemType) obj;
+				ItemType item = (ItemType) object;
 				item = item.clone();
 				ItemMeta meta = item.getItemMeta();
 				meta.setDisplayName(name);
@@ -99,13 +125,29 @@ public Object get(Object obj) {
 	}
 
 	@Override
-	public Class<? extends Object> getReturnType() {
-		return getExpr().getReturnType() == InventoryType.class ? Inventory.class : ItemType.class;
+	public Class<?> getReturnType() {
+		Class<?> returnType = getExpr().getReturnType();
+		if (returnType == InventoryType.class)
+			return Inventory.class;
+		if (returnType == ItemStack.class || returnType == ItemType.class)
+			return ItemType.class;
+		return Object.class;
 	}
 
 	@Override
-	public String toString(final @Nullable Event e, final boolean debug) {
-		return getExpr().toString(e, debug) + " named " + name;
+	public String toString(@Nullable Event event, boolean debug) {
+		return getExpr().toString(event, debug) + " named " + name;
+	}
+
+	private boolean isCreatable(InventoryType type) {
+		// Spigot forgot to label some InventoryTypes as non-creatable in some versions < 1.19.4
+		// So this throws NullPointerException as well as an IllegalArgumentException.
+		// See https://hub.spigotmc.org/jira/browse/SPIGOT-7301
+		if (Skript.isRunningMinecraft(1, 14) && type == InventoryType.COMPOSTER)
+			return false;
+		if (Skript.isRunningMinecraft(1, 20) && type == InventoryType.CHISELED_BOOKSHELF)
+			return false;
+		return type.isCreatable();
 	}
 
 }

src/test/skript/tests/regressions/5923-exprnamed-inventorytype-name-null.sk

@@ -0,0 +1,7 @@
+test "inventory type ExprNamed name null" when running minecraft "1.14.4": # 1.13 makes the inventory name return "Shulker Box"
+	set {_inventory} to shulker box inventory named name of tool of random player out of all players
+	assert {_inventory} is set with "Failed to set new inventory to local variable"
+	assert name of {_inventory} is not set with "The name of the inventory was set"
+	clear {_inventory}
+	set {_inventory} to shulker box inventory named {_null}
+	assert name of {_inventory} is not set with "The name of the inventory was set (2)"

src/test/skript/tests/syntaxes/expressions/ExprNamed.sk

@@ -0,0 +1,9 @@
+test "named":
+	set {_i} to an iron sword
+	assert name of {_i} is not set with "default item name failed: %name of {_i}%"
+	set {_i} to {_i} named "blob"
+	assert name of {_i} is "blob" with "item name failed: %name of {_i}%"
+	set {_inventory} to a hopper inventory
+	assert name of {_inventory} is not set with "default inventory name failed: %name of {_inventory}%"
+	set {_inventory} to a hopper inventory named "test"
+	assert {_inventory} is set with "inventory set failed" # we can't check inventory names any more