Swallow undeliverable RxJava exceptions

AntennaPod threads might throw NPEs after disposing because we set controllers to null.

5 files changed, 49 insertions, 6 deletions

diff --git a/app/src/main/java/de/danoeh/antennapod/PodcastApp.java b/app/src/main/java/de/danoeh/antennapod/PodcastApp.java
index ed3f4e8f1..534d48479 100644
--- a/app/src/main/java/de/danoeh/antennapod/PodcastApp.java
+++ b/app/src/main/java/de/danoeh/antennapod/PodcastApp.java
@@ -12,6 +12,8 @@ import com.joanzapata.iconify.fonts.MaterialModule;
 import de.danoeh.antennapod.activity.SplashActivity;
 import de.danoeh.antennapod.core.ApCoreEventBusIndex;
 import de.danoeh.antennapod.core.ClientConfig;
+import de.danoeh.antennapod.error.CrashReportWriter;
+import de.danoeh.antennapod.error.RxJavaErrorHandlerSetup;
 import de.danoeh.antennapod.spa.SPAUtil;
 import org.greenrobot.eventbus.EventBus;
 
@@ -38,6 +40,7 @@ public class PodcastApp extends Application {
         super.onCreate();
 
         Thread.setDefaultUncaughtExceptionHandler(new CrashReportWriter());
+        RxJavaErrorHandlerSetup.setupRxJavaErrorHandler();
 
         if (BuildConfig.DEBUG) {
             StrictMode.VmPolicy.Builder builder = new StrictMode.VmPolicy.Builder()
diff --git a/app/src/main/java/de/danoeh/antennapod/activity/BugReportActivity.java b/app/src/main/java/de/danoeh/antennapod/activity/BugReportActivity.java
index 48264bb26..fde7c0484 100644
--- a/app/src/main/java/de/danoeh/antennapod/activity/BugReportActivity.java
+++ b/app/src/main/java/de/danoeh/antennapod/activity/BugReportActivity.java
@@ -7,7 +7,7 @@ import android.os.Bundle;
 import com.google.android.material.snackbar.Snackbar;
 import androidx.appcompat.app.AppCompatActivity;
 import android.widget.TextView;
-import de.danoeh.antennapod.CrashReportWriter;
+import de.danoeh.antennapod.error.CrashReportWriter;
 import de.danoeh.antennapod.R;
 import de.danoeh.antennapod.core.preferences.UserPreferences;
 import de.danoeh.antennapod.core.util.IntentUtils;
diff --git a/app/src/main/java/de/danoeh/antennapod/CrashReportWriter.java b/app/src/main/java/de/danoeh/antennapod/error/CrashReportWriter.java
index b5d0f6945..dc62863f9 100644
--- a/app/src/main/java/de/danoeh/antennapod/CrashReportWriter.java
+++ b/app/src/main/java/de/danoeh/antennapod/error/CrashReportWriter.java
@@ -1,8 +1,9 @@
-package de.danoeh.antennapod;
+package de.danoeh.antennapod.error;
 
 import android.os.Build;
 import android.util.Log;
 
+import de.danoeh.antennapod.BuildConfig;
 import org.apache.commons.io.IOUtils;
 
 import java.io.File;
@@ -31,6 +32,11 @@ public class CrashReportWriter implements Thread.UncaughtExceptionHandler {
 
     @Override
     public void uncaughtException(Thread thread, Throwable ex) {
+        write(ex);
+        defaultHandler.uncaughtException(thread, ex);
+    }
+
+    public static void write(Throwable exception) {
         File path = getFile();
         PrintWriter out = null;
         try {
@@ -41,14 +47,13 @@ public class CrashReportWriter implements Thread.UncaughtExceptionHandler {
             out.println();
             out.println("## StackTrace");
             out.println("```");
-            ex.printStackTrace(out);
+            exception.printStackTrace(out);
             out.println("```");
         } catch (IOException e) {
             Log.e(TAG, Log.getStackTraceString(e));
         } finally {
             IOUtils.closeQuietly(out);
         }
-        defaultHandler.uncaughtException(thread, ex);
     }
 
     public static String getSystemInfo() {
diff --git a/app/src/main/java/de/danoeh/antennapod/error/RxJavaErrorHandlerSetup.java b/app/src/main/java/de/danoeh/antennapod/error/RxJavaErrorHandlerSetup.java
new file mode 100644
index 000000000..1c7f5f0b4
--- /dev/null
+++ b/app/src/main/java/de/danoeh/antennapod/error/RxJavaErrorHandlerSetup.java
@@ -0,0 +1,36 @@
+package de.danoeh.antennapod.error;
+
+import android.util.Log;
+import de.danoeh.antennapod.BuildConfig;
+import io.reactivex.exceptions.UndeliverableException;
+import io.reactivex.plugins.RxJavaPlugins;
+
+public class RxJavaErrorHandlerSetup {
+    private static final String TAG = "RxJavaErrorHandler";
+
+    private RxJavaErrorHandlerSetup() {
+
+    }
+
+    public static void setupRxJavaErrorHandler() {
+        RxJavaPlugins.setErrorHandler(exception -> {
+            if (exception instanceof UndeliverableException) {
+                // Probably just disposed because the fragment was left
+                Log.d(TAG, "Ignored exception: " + Log.getStackTraceString(exception));
+                return;
+            }
+
+            // Usually, undeliverable exceptions are wrapped in an UndeliverableException.
+            // If an undeliverable exception is a NPE (or some others), wrapping does not happen.
+            // AntennaPod threads might throw NPEs after disposing because we set controllers to null.
+            // Just swallow all exceptions here.
+            Log.e(TAG, Log.getStackTraceString(exception));
+            CrashReportWriter.write(exception);
+
+            if (BuildConfig.DEBUG) {
+                Thread.currentThread().getUncaughtExceptionHandler()
+                        .uncaughtException(Thread.currentThread(), exception);
+            }
+        });
+    }
+}
diff --git a/app/src/main/java/de/danoeh/antennapod/preferences/PreferenceUpgrader.java b/app/src/main/java/de/danoeh/antennapod/preferences/PreferenceUpgrader.java
index 367593131..7a282fc82 100644
--- a/app/src/main/java/de/danoeh/antennapod/preferences/PreferenceUpgrader.java
+++ b/app/src/main/java/de/danoeh/antennapod/preferences/PreferenceUpgrader.java
@@ -5,12 +5,11 @@ import android.content.SharedPreferences;
 import android.preference.PreferenceManager;
 
 import de.danoeh.antennapod.BuildConfig;
-import de.danoeh.antennapod.CrashReportWriter;
+import de.danoeh.antennapod.error.CrashReportWriter;
 import de.danoeh.antennapod.R;
 import de.danoeh.antennapod.core.preferences.UserPreferences;
 import de.danoeh.antennapod.core.preferences.UserPreferences.EnqueueLocation;
 import de.danoeh.antennapod.core.util.download.AutoUpdateManager;
-import de.danoeh.antennapod.core.util.gui.NotificationUtils;
 
 public class PreferenceUpgrader {
     private static final String PREF_CONFIGURED_VERSION = "version_code";