Fix core error creating item with non-item material

Until recently, creating an item stack with a material that is not an item type would work but act like an empty item stack when added to an inventory. Paper now validates if it's an item type on creation. This makes CH throw an exception on invalid item types, but continues to convert legacy block-only items to air. material_info() can now be used to check if a material "isItem".

src/main/java/com/laytonsmith/abstraction/bukkit/BukkitConvertor.java

@@ -280,7 +280,7 @@ public MCItemStack GetItemStack(String type, int qty) {
 		if(mat == null) {
 			mat = Material.matchMaterial(type);
 		}
-		if(mat == null) {
+		if(mat == null || !mat.isItem()) {
 			return null;
 		}
 		return new BukkitMCItemStack(new ItemStack(mat, qty));

src/main/java/com/laytonsmith/abstraction/bukkit/BukkitMCInventory.java

@@ -111,7 +111,7 @@ public int hashCode() {
 
 	@Override
 	public Map<Integer, MCItemStack> addItem(MCItemStack stack) {
-		Map<Integer, ItemStack> h = i.addItem(stack == null ? null : ((BukkitMCItemStack) stack).is);
+		Map<Integer, ItemStack> h = i.addItem(((BukkitMCItemStack) stack).is);
 		Map<Integer, MCItemStack> m = new HashMap<>();
 		for(Map.Entry<Integer, ItemStack> entry : h.entrySet()) {
 			Integer key = entry.getKey();

src/main/java/com/laytonsmith/core/ObjectGenerator.java

@@ -373,6 +373,9 @@ public MCItemStack item(Mixed i, Target t, boolean legacy) {
 				}
 			}
 
+			if(!material.isItem()) {
+				material = MCMaterial.get("AIR");
+			}
 			ret = StaticLayer.GetItemStack(material, qty);
 			MSLog.GetLogger().w(MSLog.Tags.DEPRECATION, "Converted \"" + mat + "\" with data \""
 					+ data + "\" to " + material.getName(), t);
@@ -472,7 +475,7 @@ public Construct itemMeta(MCItemStack is, Target t) {
 				ma.set("modifiers", CNull.NULL, t);
 			} else {
 				CArray modifiers = new CArray(t);
-				for(MCAttributeModifier m : meta.getAttributeModifiers()) {
+				for(MCAttributeModifier m : modifierList) {
 					modifiers.push(attributeModifier(m, t), t);
 				}
 				ma.set("modifiers", modifiers, t);
@@ -2421,7 +2424,7 @@ public MCRecipe recipe(Mixed c, Target t) {
 	 */
 	private MCMaterial recipeMaterial(Mixed arg, Target t) {
 		MCMaterial mat = StaticLayer.GetMaterial(arg.val());
-		if(mat == null || mat.isAir()) {
+		if(mat == null || mat.isAir() || !mat.isItem()) {
 			throw new CREIllegalArgumentException("Recipe input ingredient is invalid: " + arg.val(), t);
 		}
 		return mat;

src/main/java/com/laytonsmith/core/Static.java

@@ -785,6 +785,9 @@ public static MCItemStack ParseItemNotation(String functionName, String notation
 		if(mat == null) {
 			throw new CREFormatException("Invalid item format: " + notation, t);
 		}
+		if(!mat.isItem()) {
+			mat = MCMaterial.get("AIR");
+		}
 		MCItemStack is = StaticLayer.GetItemStack(mat, qty);
 		MSLog.GetLogger().w(MSLog.Tags.DEPRECATION, "Item notation is deprecated."
 				+ " Converting '" + notation + "' to '" + is.getType().getName() + "'.", t);

src/main/java/com/laytonsmith/core/functions/Minecraft.java

@@ -1165,6 +1165,8 @@ public Mixed exec(Target t, Environment environment, Mixed... args) throws Confi
 						return CBoolean.get(mat.hasGravity());
 					case "isBlock":
 						return CBoolean.get(mat.isBlock());
+					case "isItem":
+						return CBoolean.get(mat.isItem());
 					case "isBurnable":
 						return CBoolean.get(mat.isBurnable());
 					case "isEdible":
@@ -1202,6 +1204,7 @@ public Mixed exec(Target t, Environment environment, Mixed... args) throws Confi
 			ret.set("maxDurability", new CInt(mat.getMaxDurability(), t), t);
 			ret.set("hasGravity", CBoolean.get(mat.hasGravity()), t);
 			ret.set("isBlock", CBoolean.get(mat.isBlock()), t);
+			ret.set("isItem", CBoolean.get(mat.isItem()), t);
 			ret.set("isBurnable", CBoolean.get(mat.isBurnable()), t);
 			ret.set("isEdible", CBoolean.get(mat.isEdible()), t);
 			ret.set("isFlammable", CBoolean.get(mat.isFlammable()), t);
@@ -1230,7 +1233,7 @@ public Integer[] numArgs() {
 		@Override
 		public String docs() {
 			return "mixed {material, [trait]} Returns an array of info about the material. If a trait is specified,"
-					+ " it returns only that trait. Available traits: hasGravity, isBlock, isBurnable, isEdible,"
+					+ " it returns only that trait. Available traits: hasGravity, isBlock, isItem, isBurnable, isEdible,"
 					+ " isFlammable, isOccluding, isRecord, isSolid, isTransparent, isInteractable, maxDurability,"
 					+ " hardness (for block materials only), blastResistance (for block materials only),"
 					+ " and maxStacksize. The accuracy of these values depend on the server implementation.";