From fac13a041ed9f59ed9e21d608651a4dcd8e8be84 Mon Sep 17 00:00:00 2001
From: Adrian Sampson <adrian@radbox.org>
Date: Sun, 13 Oct 2013 18:22:43 -0700
Subject: [PATCH] missing: tolerate disctotal == None

This problem:
http://pastebin.ca/2466454
is likely indicative of a bug elsewhere, but defensive coding seems like a
good idea here.
---
 beetsplug/missing.py | 2 +-
 docs/changelog.rst   | 4 ++++
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/beetsplug/missing.py b/beetsplug/missing.py
index 0b12ebde6..fe2265da2 100644
--- a/beetsplug/missing.py
+++ b/beetsplug/missing.py
@@ -28,7 +28,7 @@ log = logging.getLogger('beets')
 def _missing_count(album):
     """Return number of missing items in `album`.
     """
-    return album.tracktotal - len([i for i in album.items()])
+    return (album.tracktotal or 0) - len(album.items())
 
 
 def _missing(album):
diff --git a/docs/changelog.rst b/docs/changelog.rst
index e39c78c6c..b1819eeae 100644
--- a/docs/changelog.rst
+++ b/docs/changelog.rst
@@ -4,6 +4,10 @@ Changelog
 1.3.2 (in development)
 ----------------------
 
+Little fixes:
+
+* :doc:`/plugins/missing`: Avoid a possible error when an album's
+  ``tracktotal`` field is missing.
 
 1.3.1 (October 12, 2013)
 ------------------------