Cancel pending purge

app/src/main/java/eu/faircode/email/ServiceSynchronize.java

@@ -46,9 +46,12 @@ import androidx.annotation.NonNull;
 import androidx.annotation.RequiresApi;
 import androidx.core.app.NotificationCompat;
 import androidx.core.content.ContextCompat;
+import androidx.lifecycle.Lifecycle;
+import androidx.lifecycle.LifecycleObserver;
 import androidx.lifecycle.MediatorLiveData;
 import androidx.lifecycle.MutableLiveData;
 import androidx.lifecycle.Observer;
+import androidx.lifecycle.OnLifecycleEvent;
 import androidx.preference.PreferenceManager;
 
 import com.sun.mail.iap.Argument;
@@ -1865,6 +1868,16 @@ public class ServiceSynchronize extends ServiceBase implements SharedPreferences
                             cowner.value = new TwoStateOwner(ServiceSynchronize.this, account.name);
                             cowner.value.start();
 
+                            Lifecycle registry = cowner.value.getLifecycle();
+                            registry.addObserver(new LifecycleObserver() {
+                                @OnLifecycleEvent(Lifecycle.Event.ON_DESTROY)
+                                public void onDestroyed() {
+                                    Log.i("Canceling pending purge");
+                                    getMainHandler().removeCallbacks(purge);
+                                    registry.removeObserver(this);
+                                }
+                            });
+
                             db.operation().liveOperations(account.id).observe(cowner.value, new Observer<List<TupleOperationEx>>() {
                                 private DutyCycle dc = new DutyCycle(account.name + " operations");
                                 private List<Long> handling = new ArrayList<>();