Fix NPE in AlarmManager.cancel(...)

If AlarmManager.cancel is called before any component has had a chance
to register an alarm, sWrappers will not have been set, as it is only
initialized in setImpl.

When cancelling an alarm and sWrappers does not exist, log a warning and
return early.

BUG: 27972657
Change-Id: Ied10719ba1d154f97eecfc32f429fd9ce39bf747

parent 9d5aadd5

core/java/android/app/AlarmManager.java

+6 −4

Original line number	Diff line number	Diff line
		@@ -905,12 +905,14 @@ public class AlarmManager {

		ListenerWrapper wrapper = null;
		synchronized (AlarmManager.class) {
		if (sWrappers != null) {
		final WeakReference<ListenerWrapper> wrapperRef;
		wrapperRef = sWrappers.get(listener);
		if (wrapperRef != null) {
		wrapper = wrapperRef.get();
		}
		}
		}

		if (wrapper == null) {
		Log.w(TAG, "Unrecognized alarm listener " + listener);