ExceptionLoggers: never have a null message

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

app/src/main/java/com/wireguard/android/QuickTileService.java

@@ -76,7 +76,7 @@ public class QuickTileService extends TileService {
                                   final Throwable throwable) {
         if (throwable == null)
             return;
-        final String error = ExceptionLoggers.unwrap(throwable).getMessage();
+        final String error = ExceptionLoggers.unwrapMessage(throwable);
         final String message = getString(R.string.toggle_error, error);
         Log.e(TAG, message, throwable);
         Toast.makeText(this, message, Toast.LENGTH_LONG).show();

app/src/main/java/com/wireguard/android/fragment/TunnelController.java

@@ -48,7 +48,7 @@ public final class TunnelController {
             if (throwable == null)
                 return;
             final Context context = view.getContext();
-            final String error = ExceptionLoggers.unwrap(throwable).getMessage();
+            final String error = ExceptionLoggers.unwrapMessage(throwable);
             final int messageResId = checked ? R.string.error_up : R.string.error_down;
             final String message = context.getString(messageResId, error);
             Snackbar.make(view, message, Snackbar.LENGTH_LONG).show();

app/src/main/java/com/wireguard/android/fragment/TunnelEditorFragment.java

@@ -54,7 +54,7 @@ public class TunnelEditorFragment extends BaseFragment {
             Toast.makeText(getContext(), message, Toast.LENGTH_SHORT).show();
             onFinished();
         } else {
-            final String error = ExceptionLoggers.unwrap(throwable).getMessage();
+            final String error = ExceptionLoggers.unwrapMessage(throwable);
             message = getString(R.string.config_save_error, savedTunnel.getName(), error);
             Log.e(TAG, message, throwable);
             if (binding != null) {
@@ -119,7 +119,7 @@ public class TunnelEditorFragment extends BaseFragment {
                 try {
                     binding.getConfig().commitData(newConfig);
                 } catch (final Exception e) {
-                    final String error = ExceptionLoggers.unwrap(e).getMessage();
+                    final String error = ExceptionLoggers.unwrapMessage(e);
                     final String tunnelName = tunnel == null ? binding.getConfig().getName() : tunnel.getName();
                     final String message = getString(R.string.config_save_error, tunnelName, error);
                     Log.e(TAG, message, e);
@@ -171,7 +171,7 @@ public class TunnelEditorFragment extends BaseFragment {
             Log.d(TAG, message);
             onFinished();
         } else {
-            final String error = ExceptionLoggers.unwrap(throwable).getMessage();
+            final String error = ExceptionLoggers.unwrapMessage(throwable);
             message = getString(R.string.tunnel_create_error, error);
             Log.e(TAG, message, throwable);
             if (binding != null) {
@@ -190,7 +190,7 @@ public class TunnelEditorFragment extends BaseFragment {
             Log.d(TAG, "Attempting to save config of renamed tunnel " + tunnel.getName());
             renamedTunnel.setConfig(newConfig).whenComplete((a, b) -> onConfigSaved(renamedTunnel, b));
         } else {
-            final String error = ExceptionLoggers.unwrap(throwable).getMessage();
+            final String error = ExceptionLoggers.unwrapMessage(throwable);
             message = getString(R.string.tunnel_rename_error, error);
             Log.e(TAG, message, throwable);
             if (binding != null) {

app/src/main/java/com/wireguard/android/fragment/TunnelListFragment.java

@@ -239,7 +239,7 @@ public class TunnelListFragment extends BaseFragment {
         if (throwable == null) {
             message = getResources().getQuantityString(R.plurals.delete_success, count, count);
         } else {
-            final String error = ExceptionLoggers.unwrap(throwable).getMessage();
+            final String error = ExceptionLoggers.unwrapMessage(throwable);
             message = getResources().getQuantityString(R.plurals.delete_error, count, count, error);
             Log.e(TAG, message, throwable);
         }
@@ -252,7 +252,7 @@ public class TunnelListFragment extends BaseFragment {
         String message = null;
 
         for (final Throwable throwable : throwables) {
-            final String error = ExceptionLoggers.unwrap(throwable).getMessage();
+            final String error = ExceptionLoggers.unwrapMessage(throwable);
             message = getString(R.string.import_error, error);
             Log.e(TAG, message, throwable);
         }

app/src/main/java/com/wireguard/android/preference/ZipExporterPreference.java

@@ -102,7 +102,7 @@ public class ZipExporterPreference extends Preference {
 
     private void exportZipComplete(final String filePath, final Throwable throwable) {
         if (throwable != null) {
-            final String error = ExceptionLoggers.unwrap(throwable).getMessage();
+            final String error = ExceptionLoggers.unwrapMessage(throwable);
             final String message = getContext().getString(R.string.export_error, error);
             Log.e(TAG, message, throwable);
             Snackbar.make(

app/src/main/java/com/wireguard/android/util/ExceptionLoggers.java

@@ -6,8 +6,8 @@
 
 package com.wireguard.android.util;
 
+import android.support.annotation.NonNull;
 import android.util.Log;
-
 import java9.util.concurrent.CompletionException;
 import java9.util.function.BiConsumer;
 
@@ -29,11 +29,20 @@ public enum ExceptionLoggers implements BiConsumer<Object, Throwable> {
     }
 
     public static Throwable unwrap(final Throwable throwable) {
-        if (throwable instanceof CompletionException)
+        if (throwable instanceof CompletionException && throwable.getCause() != null)
             return throwable.getCause();
         return throwable;
     }
 
+    @NonNull
+    public static String unwrapMessage(Throwable throwable) {
+        throwable = unwrap(throwable);
+        final String message = throwable.getMessage();
+        if (message != null)
+            return message;
+        return throwable.getClass().getSimpleName();
+    }
+
     @Override
     public void accept(final Object result, final Throwable throwable) {
         if (throwable != null)