MemoryHabitList: Inherit parent's order

Fixes #598

android/uhabits-core/src/main/java/org/isoron/uhabits/core/models/memory/MemoryHabitList.java

@@ -55,6 +55,7 @@ public class MemoryHabitList extends HabitList
         super(matcher);
         this.parent = parent;
         this.comparator = comparator;
+        this.order = parent.order;
         parent.getObservable().addListener(this::loadFromParent);
         loadFromParent();
     }

android/uhabits-core/src/test/java/org/isoron/uhabits/core/models/HabitListTest.java

@@ -31,8 +31,7 @@ import static junit.framework.TestCase.assertFalse;
 import static org.hamcrest.CoreMatchers.*;
 import static org.hamcrest.MatcherAssert.assertThat;
 import static org.isoron.uhabits.core.models.HabitList.Order.*;
-import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.*;
-import static org.junit.Assert.assertNull;
 
 @SuppressWarnings("JavaDoc")
 public class HabitListTest extends BaseUnitTest
@@ -211,6 +210,17 @@ public class HabitListTest extends BaseUnitTest
         habitList.reorder(h1, h2);
     }
 
+    @Test
+    public void testOrder_inherit()
+    {
+        habitList.setOrder(BY_COLOR_ASC);
+        HabitList filteredList = habitList.getFiltered(new HabitMatcherBuilder()
+                                                               .setArchivedAllowed(false)
+                                                               .setCompletedAllowed(false)
+                                                               .build());
+        assertEquals(filteredList.getOrder(), BY_COLOR_ASC);
+    }
+
     @Test
     public void testWriteCSV() throws IOException
     {