Prevent crash

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

@@ -2,18 +2,46 @@ package eu.faircode.email;
 
 import android.content.DialogInterface;
 import android.content.Intent;
+import android.os.Bundle;
 
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 import androidx.fragment.app.DialogFragment;
 import androidx.fragment.app.Fragment;
 import androidx.fragment.app.FragmentManager;
+import androidx.lifecycle.Lifecycle;
+import androidx.lifecycle.LifecycleObserver;
+import androidx.lifecycle.OnLifecycleEvent;
 
 import static android.app.Activity.RESULT_CANCELED;
 
 public class FragmentDialogEx extends DialogFragment {
     private boolean once = false;
 
+    @Override
+    public void onCreate(@Nullable Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        Log.i("Create " + this);
+    }
+
+    @Override
+    public void onResume() {
+        super.onResume();
+        Log.i("Resume " + this);
+    }
+
+    @Override
+    public void onPause() {
+        super.onPause();
+        Log.i("Pause " + this);
+    }
+
+    @Override
+    public void onDestroy() {
+        super.onDestroy();
+        Log.i("Destroy " + this);
+    }
+
     @Override
     public void onStart() {
         try {
@@ -40,6 +68,20 @@ public class FragmentDialogEx extends DialogFragment {
         super.onDismiss(dialog);
     }
 
+    @Override
+    public void setTargetFragment(@Nullable Fragment fragment, int requestCode) {
+        super.setTargetFragment(fragment, requestCode);
+        Log.i("Set target " + this + " " + fragment);
+
+        fragment.getViewLifecycleOwner().getLifecycle().addObserver(new LifecycleObserver() {
+            @OnLifecycleEvent(Lifecycle.Event.ON_DESTROY)
+            public void onDestroy() {
+                Log.i("Reset target " + FragmentDialogEx.this);
+                FragmentDialogEx.super.setTargetFragment(null, requestCode);
+            }
+        });
+    }
+
     protected void sendResult(int result) {
         if (!once) {
             once = true;