From 87f1de1dc5e6297ec09bd2319833bbad83993466 Mon Sep 17 00:00:00 2001
From: Ethan Dalool <ethan@voussoir.net>
Date: Sun, 18 Aug 2019 22:38:40 -0700
Subject: [PATCH] In move_nav_to_end, add nav to spine if not present.

---
 epubfile.py | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/epubfile.py b/epubfile.py
index 87e2598..4c067da 100644
--- a/epubfile.py
+++ b/epubfile.py
@@ -839,8 +839,10 @@ class Epub:
             if id == nav:
                 spine.append(spine.pop(index))
                 break
-        self.set_spine_order(spine)
+        else:
+            spine.append(nav)
 
+        self.set_spine_order(spine)
         self.set_spine_linear(nav, False)
 
     def normalize_directory_structure(self):