From 14e4682f29b9fbe33deb5b6f0362e55136a76c49 Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Mon, 18 Mar 2019 07:34:36 +0530
Subject: [PATCH] Fix #1820548 [Backups
 backtrace](https://bugs.launchpad.net/calibre/+bug/1820548)

---
 src/calibre/gui2/actions/choose_library.py | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/calibre/gui2/actions/choose_library.py b/src/calibre/gui2/actions/choose_library.py
index cf757e17a6..eb77c77610 100644
--- a/src/calibre/gui2/actions/choose_library.py
+++ b/src/calibre/gui2/actions/choose_library.py
@@ -195,6 +195,8 @@ class BackupStatus(QDialog):  # {{{
 
     def mark_all_dirty(self):
         db = self.db()
+        if db is None:
+            return
         db.new_api.mark_as_dirty(db.new_api.all_book_ids())
 
 # }}}