From 70da6eaa1204540269a71f6e658c7f9efb084090 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20Mart=C3=AD?= <mvdan@mvdan.cc>
Date: Sun, 24 Apr 2016 14:57:32 +0100
Subject: [PATCH] Fix NPE when clicking on missing app links

This happened to me when I clicked on an app link for a new app which
was already in the repo, but I had not ran an index update yet since the
app got built. Stack trace prior to the fix follows.

	java.lang.RuntimeException: Unable to destroy activity {org.fdroid.fdroid/org.fdroid.fdroid.AppDetails}: java.lang.NullPointerException:
	Attempt to invoke virtual method 'void android.support.v4.content.LocalBroadcastManager.unregisterReceiver(android.content.BroadcastReceiver)' on a null
	object reference
		at android.app.ActivityThread.performDestroyActivity(ActivityThread.java:3865)
		at android.app.ActivityThread.handleDestroyActivity(ActivityThread.java:3883)
		at android.app.ActivityThread.-wrap5(ActivityThread.java)
		at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1417)
		at android.os.Handler.dispatchMessage(Handler.java:102)
		at android.os.Looper.loop(Looper.java:148)
		at android.app.ActivityThread.main(ActivityThread.java:5461)
		at java.lang.reflect.Method.invoke(Native Method)
		at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
		at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
	Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void
	android.support.v4.content.LocalBroadcastManager.unregisterReceiver(android.content.BroadcastReceiver)' on a null object reference
		at org.fdroid.fdroid.AppDetails.unregisterDownloaderReceivers(AppDetails.java:469)
		at org.fdroid.fdroid.AppDetails.onDestroy(AppDetails.java:569)
		at android.app.Activity.performDestroy(Activity.java:6422)
		at android.app.Instrumentation.callActivityOnDestroy(Instrumentation.java:1143)
		at android.app.ActivityThread.performDestroyActivity(ActivityThread.java:3852)
		... 9 more
---
 app/src/main/java/org/fdroid/fdroid/AppDetails.java | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/app/src/main/java/org/fdroid/fdroid/AppDetails.java b/app/src/main/java/org/fdroid/fdroid/AppDetails.java
index 073a86a14..c29e6ae36 100644
--- a/app/src/main/java/org/fdroid/fdroid/AppDetails.java
+++ b/app/src/main/java/org/fdroid/fdroid/AppDetails.java
@@ -466,6 +466,9 @@ public class AppDetails extends AppCompatActivity {
     }
 
     private void unregisterDownloaderReceivers() {
+        if (localBroadcastManager == null) {
+            return;
+        }
         localBroadcastManager.unregisterReceiver(startedReceiver);
         localBroadcastManager.unregisterReceiver(progressReceiver);
         localBroadcastManager.unregisterReceiver(completeReceiver);