TEST: Unit test to guard against the server not updating list props.

This is an additional safeguard against issue #217, in addition to the existing Python integration
test.

src/test/java/org/caosdb/server/transaction/UpdateTest.java

@@ -256,4 +256,36 @@ public class UpdateTest {
     assertEquals(newEntity.getEntityStatus(), QUALIFIED);
     assertEquals(newProperty.getEntityStatus(), QUALIFIED);
   }
+
+  /**
+   * For issue #217: Server gets list property datatype wrong if description is updated.
+   */
+  @Test
+  public void testDeriveUpdate_UpdateList()
+      throws NoSuchAlgorithmException, CaosDBException, IOException {
+    final Property oldProperty = new Property(1);
+    final Property newProperty = new Property(1);
+    oldProperty.setDatatype("List<Person>");
+    newProperty.setDatatype("List<Person>");
+    final Entity oldEntity = new Entity();
+    final Entity newEntity = new Entity();
+
+    oldProperty.setRole("Record");
+    newProperty.setRole("Property");
+    oldEntity.addProperty(oldProperty);
+    newEntity.addProperty(newProperty);
+
+    // The only difference between old and new
+    newEntity.setDescription("New description.");
+
+    new WriteTransaction(null).deriveUpdate(newEntity, oldEntity);
+    // check if newEntity's Property is QUALIFIED.
+    assertEquals(QUALIFIED, newEntity.getProperties().get(0).getEntityStatus());
+
+    // CheckPropValid checkJob = new CheckPropValid();
+    // checkJob.init(null, newEntity, null);
+    // checkJob.run();
+    // assertTrue(newEntity.getProperties().get(0).isDatatypeOverride());
+
+  }
 }