Merge "Fix document stack."
diff --git a/packages/DocumentsUI/src/com/android/documentsui/State.java b/packages/DocumentsUI/src/com/android/documentsui/State.java
index 14ff902..2f0224f 100644
--- a/packages/DocumentsUI/src/com/android/documentsui/State.java
+++ b/packages/DocumentsUI/src/com/android/documentsui/State.java
@@ -105,7 +105,7 @@
     }
 
     public void pushDocument(DocumentInfo info) {
-        stack.add(info);
+        stack.push(info);
         mStackTouched = true;
     }
 
diff --git a/packages/DocumentsUI/tests/src/com/android/documentsui/StateTest.java b/packages/DocumentsUI/tests/src/com/android/documentsui/StateTest.java
new file mode 100644
index 0000000..b74b985
--- /dev/null
+++ b/packages/DocumentsUI/tests/src/com/android/documentsui/StateTest.java
@@ -0,0 +1,40 @@
+/*
+ * Copyright (C) 2016 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.documentsui;
+
+import android.test.AndroidTestCase;
+import android.test.suitebuilder.annotation.SmallTest;
+
+import com.android.documentsui.model.DocumentInfo;
+
+@SmallTest
+public class StateTest extends AndroidTestCase {
+    public void testPushDocument() {
+        final State state = new State();
+        final DocumentInfo infoFirst = new DocumentInfo();
+        infoFirst.displayName = "firstDirectory";
+        final DocumentInfo infoSecond = new DocumentInfo();
+        infoSecond.displayName = "secondDirectory";
+        assertFalse(state.hasLocationChanged());
+        state.pushDocument(infoFirst);
+        state.pushDocument(infoSecond);
+        assertTrue(state.hasLocationChanged());
+        assertEquals("secondDirectory", state.stack.getFirst().displayName);
+        state.popDocument();
+        assertEquals("firstDirectory", state.stack.getFirst().displayName);
+    }
+}