From 0749d4716cd14e7505a6df5c4da81328a6f6cbce Mon Sep 17 00:00:00 2001
From: Adrian Sampson <adrian@radbox.org>
Date: Sat, 11 Oct 2014 12:28:41 -0700
Subject: [PATCH] duplicates: Fix #999 (check "checksum" type)

---
 beetsplug/duplicates.py | 4 ++++
 docs/changelog.rst      | 2 ++
 2 files changed, 6 insertions(+)

diff --git a/beetsplug/duplicates.py b/beetsplug/duplicates.py
index fe0f8ac00..8e0af4ab7 100644
--- a/beetsplug/duplicates.py
+++ b/beetsplug/duplicates.py
@@ -209,6 +209,10 @@ class DuplicatesPlugin(BeetsPlugin):
                 fmt += ': {0}'
 
             if checksum:
+                if not isinstance(checksum, basestring):
+                    raise UserError(
+                        'duplicates: "checksum" option must be a command'
+                    )
                 for i in items:
                     k, _ = _checksum(i, checksum)
                 keys = [k]
diff --git a/docs/changelog.rst b/docs/changelog.rst
index 33d7a8694..d89a5cd38 100644
--- a/docs/changelog.rst
+++ b/docs/changelog.rst
@@ -30,6 +30,8 @@ Fixes:
   beets and instead fail silently.
 * Slow queries, such as those over flexible attributes, should now be much
   faster when used with certain commands---notably, the :doc:`/plugins/play`.
+* :doc:`/plugins/duplicates`: Emit an error when the ``checksum`` config
+  option is set incorrectly.
 
 
 1.3.8 (September 17, 2014)