Reverted version number change, added check for null

pom.xml

@@ -123,7 +123,7 @@
 		<dependency>
 			<groupId>de.jeff_media</groupId>
 			<artifactId>ChestSortAPI</artifactId>
-			<version>1.1.0</version>
+			<version>1.0.0</version>
 			<scope>compile</scope>
 		</dependency>
 		<dependency>

src/main/java/de/jeff_media/ChestSort/ChestSortOrganizer.java

@@ -343,6 +343,11 @@ public class ChestSortOrganizer {
 
     // Generate a map of "{placeholder}", "sortString" pairs for an ItemStack
     Map<String, String> getSortableMap(ItemStack item) {
+        if (item == null) {
+            // Empty map for non-item
+            return new HashMap<String, String>();
+        }
+
         String blocksFirst;
         String itemsFirst;
         if (item.getType().isBlock()) {