From 21b866840368e20de520d0738f84f30170f67255 Mon Sep 17 00:00:00 2001
From: Stefan Martynkiw <stefan_martynkiw@trimble.com>
Date: Mon, 1 Oct 2018 11:57:10 -0600
Subject: [PATCH] Prevent NPE on log line. Use monotonically increasing time
 for alarm manager scheduling calculations.

https://developer.android.com/training/scheduling/alarms
"There are two general clock types for alarms: "elapsed real time" and "real time clock" (RTC). Elapsed real time uses the "time since system boot" as a reference, and real time clock uses UTC (wall clock) time. This means that elapsed real time is suited to setting an alarm based on the passage of time (for example, an alarm that fires every 30 seconds) since it isn't affected by time zone/locale. The real time clock type is better suited for alarms that are dependent on current locale."

https://stackoverflow.com/a/15400014
---
 .../eclipse/paho/android/service/AlarmPingSender.java | 11 +++++++----
 .../eclipse/paho/android/service/MqttConnection.java  |  9 +++++++--
 2 files changed, 14 insertions(+), 6 deletions(-)

diff --git a/org.eclipse.paho.android.service/src/main/java/org/eclipse/paho/android/service/AlarmPingSender.java b/org.eclipse.paho.android.service/src/main/java/org/eclipse/paho/android/service/AlarmPingSender.java
index e88b1afa..7967706b 100755
--- a/org.eclipse.paho.android.service/src/main/java/org/eclipse/paho/android/service/AlarmPingSender.java
+++ b/org.eclipse.paho.android.service/src/main/java/org/eclipse/paho/android/service/AlarmPingSender.java
@@ -24,6 +24,8 @@
 import android.os.Build;
 import android.os.PowerManager;
 import android.os.PowerManager.WakeLock;
+import android.os.SystemClock;
+import android.support.annotation.NonNull;
 import android.util.Log;
 
 import org.eclipse.paho.client.mqttv3.IMqttActionListener;
@@ -101,19 +103,20 @@ public void stop() {
 
     @Override
     public void schedule(long delayInMilliseconds) {
-        long nextAlarmInMilliseconds = System.currentTimeMillis() + delayInMilliseconds;
+
+        long nextAlarmInMilliseconds = SystemClock.elapsedRealtime() + delayInMilliseconds;
         Log.d(TAG, "Schedule next alarm at " + nextAlarmInMilliseconds);
         AlarmManager alarmManager = (AlarmManager) service.getSystemService(Service.ALARM_SERVICE);
         if (Build.VERSION.SDK_INT >= 23) {
             // In SDK 23 and above, dosing will prevent setExact, setExactAndAllowWhileIdle will force
             // the device to run this task whilst dosing.
             Log.d(TAG, "Alarm scheule using setExactAndAllowWhileIdle, next: " + delayInMilliseconds);
-            alarmManager.setExactAndAllowWhileIdle(AlarmManager.RTC_WAKEUP, nextAlarmInMilliseconds, pendingIntent);
+            alarmManager.setExactAndAllowWhileIdle(AlarmManager.ELAPSED_REALTIME_WAKEUP, nextAlarmInMilliseconds, pendingIntent);
         } else if (Build.VERSION.SDK_INT >= 19) {
             Log.d(TAG, "Alarm scheule using setExact, delay: " + delayInMilliseconds);
-            alarmManager.setExact(AlarmManager.RTC_WAKEUP, nextAlarmInMilliseconds, pendingIntent);
+            alarmManager.setExact(AlarmManager.ELAPSED_REALTIME_WAKEUP, nextAlarmInMilliseconds, pendingIntent);
         } else {
-            alarmManager.set(AlarmManager.RTC_WAKEUP, nextAlarmInMilliseconds, pendingIntent);
+            alarmManager.set(AlarmManager.ELAPSED_REALTIME_WAKEUP, nextAlarmInMilliseconds, pendingIntent);
         }
     }
 
diff --git a/org.eclipse.paho.android.service/src/main/java/org/eclipse/paho/android/service/MqttConnection.java b/org.eclipse.paho.android.service/src/main/java/org/eclipse/paho/android/service/MqttConnection.java
index 28bf7c10..f5e3d0aa 100755
--- a/org.eclipse.paho.android.service/src/main/java/org/eclipse/paho/android/service/MqttConnection.java
+++ b/org.eclipse.paho.android.service/src/main/java/org/eclipse/paho/android/service/MqttConnection.java
@@ -17,6 +17,7 @@
 import android.os.Bundle;
 import android.os.PowerManager;
 import android.os.PowerManager.WakeLock;
+import android.support.annotation.Nullable;
 import android.util.Log;
 
 import org.eclipse.paho.android.service.MessageStore.StoredMessage;
@@ -657,8 +658,12 @@ public IMqttDeliveryToken[] getPendingDeliveryTokens() {
      * @param why the exeception causing the break in communications
      */
     @Override
-    public void connectionLost(Throwable why) {
-        service.traceDebug(TAG, "connectionLost(" + why.getMessage() + ")");
+    public void connectionLost(@Nullable Throwable why) {
+        if (why != null) {
+            service.traceDebug(TAG, "connectionLost(" + why.getMessage() + ")");
+        } else {
+            service.traceDebug(TAG, "connectionLost(NO_REASON)");
+        }
         disconnected = true;
         try {
             if (!this.connectOptions.isAutomaticReconnect()) {