Entering symbol view causes NPE when "Switch Access" accessibility mode is enabled

[GoogleCodeExporter]

What steps will reproduce the problem?
1. Enable "Switch Access" under accessibility settings (see the attached 
screenshot).
2. Tap a text area to launch Mozc
3. Tap symbol icon to enter symbol view (see the attached screenrecord).

What is the expected output?
Symbol view is displayed without any error.

What do you see instead?
Mozc crashes due to NPE.

Please use labels and text to provide additional information.
Reproduced with in the following configuration.
- Android 5.0 LPX21P on Nexus 7 2013 (WiFi)
- Mozc 2.16.1925.103-arm

Here is the call stack.
E/AndroidRuntime( 7701): FATAL EXCEPTION: main
E/AndroidRuntime( 7701): Process: org.mozc.android.inputmethod.japanese, PID: 
7701
E/AndroidRuntime( 7701): java.lang.NullPointerException: Attempt to invoke 
interface method 'boolean 
android.view.ViewParent.requestSendAccessibilityEvent(android.view.View, 
android.view.accessibility.AccessibilityEvent)' on a null object reference
E/AndroidRuntime( 7701):        at 
android.view.View.sendAccessibilityEventUncheckedInternal(View.java:5294)
E/AndroidRuntime( 7701):        at 
android.view.View.sendAccessibilityEventUnchecked(View.java:5275)
E/AndroidRuntime( 7701):        at 
android.view.View$SendViewStateChangedAccessibilityEvent.run(View.java:20892)
E/AndroidRuntime( 7701):        at 
android.os.Handler.handleCallback(Handler.java:739)
E/AndroidRuntime( 7701):        at 
android.os.Handler.dispatchMessage(Handler.java:95)
E/AndroidRuntime( 7701):        at android.os.Looper.loop(Looper.java:135)
E/AndroidRuntime( 7701):        at 
android.app.ActivityThread.main(ActivityThread.java:5221)
E/AndroidRuntime( 7701):        at java.lang.reflect.Method.invoke(Native 
Method)
E/AndroidRuntime( 7701):        at 
java.lang.reflect.Method.invoke(Method.java:372)
E/AndroidRuntime( 7701):        at 
com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:899)
E/AndroidRuntime( 7701):        at 
com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694)

This issue was originally reported as Issue 253.

Original issue reported on code.google.com by yukawa@google.com on 29 Nov 2014 at 11:01

Attachments:

• switch-access.png
• crash.mp4