From 84feea1185b8f438f9c7153b9e59bb7361b0a17d Mon Sep 17 00:00:00 2001
From: Alan Viverette <alanv@google.com>
Date: Tue, 4 Nov 2014 15:59:55 -0800
Subject: [PATCH] Abort accessibility node prefetch if parent node is null

BUG: 18004444
Change-Id: I80757daeb6b381947c4f3abbd762711cff2a978c
---
 .../view/AccessibilityInteractionController.java     | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/core/java/android/view/AccessibilityInteractionController.java b/core/java/android/view/AccessibilityInteractionController.java
index 1cadf69d4b7c3..5e05683be3d0f 100644
--- a/core/java/android/view/AccessibilityInteractionController.java
+++ b/core/java/android/view/AccessibilityInteractionController.java
@@ -1109,15 +1109,17 @@ final class AccessibilityInteractionController {
                         || accessibilityViewId == providerHost.getAccessibilityViewId()) {
                     final AccessibilityNodeInfo parent;
                     if (virtualDescendantId != AccessibilityNodeInfo.UNDEFINED_ITEM_ID) {
-                        parent = provider.createAccessibilityNodeInfo(
-                                virtualDescendantId);
+                        parent = provider.createAccessibilityNodeInfo(virtualDescendantId);
                     } else {
-                        parent= provider.createAccessibilityNodeInfo(
+                        parent = provider.createAccessibilityNodeInfo(
                                 AccessibilityNodeProvider.HOST_VIEW_ID);
                     }
-                    if (parent != null) {
-                        outInfos.add(parent);
+                    if (parent == null) {
+                        // Couldn't obtain the parent, which means we have a
+                        // disconnected sub-tree. Abort prefetch immediately.
+                        return;
                     }
+                    outInfos.add(parent);
                     parentNodeId = parent.getParentNodeId();
                     accessibilityViewId = AccessibilityNodeInfo.getAccessibilityViewId(
                             parentNodeId);