java.lang.NullPointerException when clicking on ActionBar MenuItem

[bhaskarmurthy]

I recently upgraded to v4.3.0, and am seeing an odd NullPointerException when clicking on a MenuItem.

The device is a Samsung Galaxy S, running JB from CyanogenMod 10 (as it's the only way I can get JB on this old device). Fresh OS install, completely stock otherwise.

The full stack trace looks like:

04-18 17:02:46.255: E/AndroidRuntime(3919): FATAL EXCEPTION: main
04-18 17:02:46.255: E/AndroidRuntime(3919): java.lang.NullPointerException
04-18 17:02:46.255: E/AndroidRuntime(3919):     at com.android.internal.view.menu.MenuItemImpl.toString(MenuItemImpl.java:496)
04-18 17:02:46.255: E/AndroidRuntime(3919):     at java.lang.StringBuilder.append(StringBuilder.java:202)
04-18 17:02:46.255: E/AndroidRuntime(3919):     at com.actionbarsherlock.app.SherlockFragmentActivity.onMenuItemSelected(SherlockFragmentActivity.java:201)
04-18 17:02:46.255: E/AndroidRuntime(3919):     at com.android.internal.policy.impl.PhoneWindow.onMenuItemSelected(PhoneWindow.java:980)
04-18 17:02:46.255: E/AndroidRuntime(3919):     at com.android.internal.view.menu.MenuBuilder.dispatchMenuItemSelected(MenuBuilder.java:735)
04-18 17:02:46.255: E/AndroidRuntime(3919):     at com.android.internal.view.menu.MenuItemImpl.invoke(MenuItemImpl.java:149)
04-18 17:02:46.255: E/AndroidRuntime(3919):     at com.android.internal.view.menu.MenuBuilder.performItemAction(MenuBuilder.java:874)
04-18 17:02:46.255: E/AndroidRuntime(3919):     at com.android.internal.view.menu.ActionMenuView.invokeItem(ActionMenuView.java:547)
04-18 17:02:46.255: E/AndroidRuntime(3919):     at com.android.internal.view.menu.ActionMenuItemView.onClick(ActionMenuItemView.java:115)
04-18 17:02:46.255: E/AndroidRuntime(3919):     at android.view.View.performClick(View.java:4204)
04-18 17:02:46.255: E/AndroidRuntime(3919):     at android.view.View$PerformClick.run(View.java:17355)
04-18 17:02:46.255: E/AndroidRuntime(3919):     at android.os.Handler.handleCallback(Handler.java:725)
04-18 17:02:46.255: E/AndroidRuntime(3919):     at android.os.Handler.dispatchMessage(Handler.java:92)
04-18 17:02:46.255: E/AndroidRuntime(3919):     at android.os.Looper.loop(Looper.java:137)
04-18 17:02:46.255: E/AndroidRuntime(3919):     at android.app.ActivityThread.main(ActivityThread.java:5226)
04-18 17:02:46.255: E/AndroidRuntime(3919):     at java.lang.reflect.Method.invokeNative(Native Method)
04-18 17:02:46.255: E/AndroidRuntime(3919):     at java.lang.reflect.Method.invoke(Method.java:511)
04-18 17:02:46.255: E/AndroidRuntime(3919):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:795)
04-18 17:02:46.255: E/AndroidRuntime(3919):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:562)
04-18 17:02:46.255: E/AndroidRuntime(3919):     at dalvik.system.NativeStart.main(Native Method)

After attaching the debugger, the culprit line seems to be:

        if (BuildConfig.DEBUG) Log.d(TAG, "[onMenuItemSelected] featureId: " + featureId + ", item: " + item);

in method public final boolean onMenuItemSelected(int featureId, android.view.MenuItem item)

When inspecting the item property, I see a com.sun.jdi.InvocationException occurred invoking method.

Any thoughts?
Thanks.

[bhaskarmurthy]

As an aside, if I remove the logging statement, it works fine.

[JakeWharton]

Sounds like it might be a CyanogenMod bug in their toString method of MenuItemImpl. The stock Android source lines don't match up with your trace. I'm too lazy to look at their source right now...

[JakeWharton]

In any case, this will only affect debug builds of your app, thankfully. Release versions won't have any logging!

[bhaskarmurthy]

Sounds good. I'll just comment it out during development.
Thanks for the quick reply.

[mykola-dev]

i have exactly same issue. Not using cyanogen. Stock firmware.

[hooked82]

I have the same issue on stock firmware. (Galaxy Nexus)

Commenting out the line of code fixes the problem, but what is the root cause of this? I've never ran into this until updating to the latest version recently.

[SimonVT]

You really should give your menu items a title, even if it's not shown in the action bar. It'll show up when the item is long clicked.

[JakeWharton]

You really should give your menu items a title.

100% agree. Regardless, I'll push a dot release soon to save you all from yourselves if you choose not to do this.

[hooked82]

Is this the real solution? I didn't see that as a suggestion here otherwise I would have just done that. Thanks for the tip.

[SimonVT]

Yes, that's the solution. It crashes when it tries to call toString() on mTitle.

[neoh-zz]

In the inevitable case that the menu item is purposely not set, this nullpointerexception can be solved by making the toString() method in com.android.internal.view.menu.MenuItemImpl class to do a null string check before return:

@Override
public String toString() {
    return (mTitle != null)? mTitle.toString(): "";
}