Explicit exceptions

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

@@ -64,6 +64,7 @@ import java.io.ByteArrayInputStream;
 import java.io.ByteArrayOutputStream;
 import java.io.File;
 import java.io.FileInputStream;
+import java.io.FileNotFoundException;
 import java.io.FileOutputStream;
 import java.io.FileReader;
 import java.io.IOException;
@@ -1424,7 +1425,7 @@ public class ActivityView extends ActivityBilling implements FragmentManager.OnB
                 DB db = DB.getInstance(context);
                 EntityMessage message = db.message().getMessage(id);
                 if (message == null)
-                    return null;
+                    throw new FileNotFoundException();
                 File file = message.getRawFile(context);
                 Log.i("Raw file=" + file);
 
@@ -1498,7 +1499,7 @@ public class ActivityView extends ActivityBilling implements FragmentManager.OnB
                 DB db = DB.getInstance(context);
                 EntityAttachment attachment = db.attachment().getAttachment(id);
                 if (attachment == null)
-                    return null;
+                    throw new FileNotFoundException();
                 File file = attachment.getFile(context);
 
                 ParcelFileDescriptor pfd = null;

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

@@ -41,6 +41,8 @@ import android.widget.TextView;
 import android.widget.Toast;
 
 import java.io.File;
+import java.io.FileNotFoundException;
+import java.io.IOException;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.Comparator;
@@ -170,13 +172,13 @@ public class AdapterAttachment extends RecyclerView.Adapter<AdapterAttachment.Vi
 
             new SimpleTask<Void>() {
                 @Override
-                protected Void onExecute(Context context, Bundle args) {
+                protected Void onExecute(Context context, Bundle args) throws IOException {
                     long id = args.getLong("id");
 
                     DB db = DB.getInstance(context);
                     EntityAttachment attachment = db.attachment().getAttachment(id);
                     if (attachment == null)
-                        return null;
+                        throw new FileNotFoundException();
                     db.attachment().setDownloaded(id, null);
                     attachment.getFile(context).delete();
                     db.attachment().deleteAttachment(id);

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

@@ -561,7 +561,7 @@ public class FragmentCompose extends FragmentBase {
                 DB db = DB.getInstance(context);
                 EntityMessage draft = db.message().getMessage(id);
                 if (draft == null)
-                    return null;
+                    throw new FileNotFoundException();
 
                 File file = draft.getFile(context);
                 File refFile = draft.getRefFile(context);