Null check on item passed to claim()

Author: kshepherd

dspace-api/src/main/java/org/dspace/profile/ResearcherProfileServiceImpl.java

@@ -200,6 +200,10 @@ public ResearcherProfile claim(Context context, EPerson ePerson, URI uri)
     public ResearcherProfile claim(Context context, EPerson ePerson, Item item)
         throws SQLException, AuthorizeException {
 
+        if (item == null) {
+            throw new IllegalArgumentException("The provided item is null");
+        }
+
         if (!item.isArchived() || item.isWithdrawn()) {
             throw new IllegalArgumentException(
                 "Only archived items can be claimed to create a researcher profile. Item ID: " + item.getID());