From e24adc0e35c288f2155bd3147b226ec9b5d494bc Mon Sep 17 00:00:00 2001
From: Charles Haley <>
Date: Tue, 10 Apr 2012 18:16:42 +0200
Subject: [PATCH] Prevent exceptions when 1) both author and author_sort are
 used in "add" templates, and 2) books are added from a device, and 3) read
 metadata from file contents is not checked.

---
 src/calibre/devices/usbms/driver.py | 10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/src/calibre/devices/usbms/driver.py b/src/calibre/devices/usbms/driver.py
index 17e131a76b..a5ab0bd15c 100644
--- a/src/calibre/devices/usbms/driver.py
+++ b/src/calibre/devices/usbms/driver.py
@@ -402,14 +402,12 @@ class USBMS(CLI, Device):
     def build_template_regexp(cls):
         def replfunc(match, seen=None):
             v = match.group(1)
-            if v in ['title', 'series', 'series_index', 'isbn']:
+            if v in ['authors', 'author_sort']:
+                v = 'author'
+            if v in ('title', 'series', 'series_index', 'isbn', 'author'):
                 if v not in seen:
-                    seen |= set([v])
+                    seen.add(v)
                     return '(?P<' + v + '>.+?)'
-            elif v in ['authors', 'author_sort']:
-                if v not in seen:
-                    seen |= set([v])
-                    return '(?P<author>.+?)'
             return '(.+?)'
         s = set()
         f = functools.partial(replfunc, seen=s)