From 04404a2f4fc986ea02a606d4faead6eca0e0e541 Mon Sep 17 00:00:00 2001
From: Toshiaki Baba <toshiaki@netmark.jp>
Date: Sun, 3 May 2015 00:45:17 +0900
Subject: [PATCH] avoid AttributeError: 'NoneType' object has no attribute
 'append'

---
 lpod/document.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/lpod/document.py b/lpod/document.py
index 18e54f9..831d0a2 100644
--- a/lpod/document.py
+++ b/lpod/document.py
@@ -603,7 +603,8 @@ def insert_style(self, style, name=None, automatic=False, default=False):
         # Insert it!
         if existing is not None:
             container.delete(existing)
-        container.append(style)
+        if container:
+            container.append(style)
         return style.get_name()