Error handling for 'filesize' field

- Logs a warning and returns 0 if getsize fails
- Add tests for this

Fix #1326

beets/library.py

@@ -421,7 +421,7 @@ class Item(LibModel):
         getters = plugins.item_field_getters()
         getters['singleton'] = lambda i: i.album_id is None
         # Filesize is given in bytes
-        getters['filesize'] = lambda i: os.path.getsize(syspath(i.path))
+        getters['filesize'] = lambda i: i.try_filesize()
         return getters
 
     @classmethod
@@ -605,6 +605,13 @@ class Item(LibModel):
         """
         return int(os.path.getmtime(syspath(self.path)))
 
+    def try_filesize(self):
+        try:
+            return os.path.getsize(syspath(self.path))
+        except (OSError, Exception) as exc:
+            log.warning(u'could not get filesize: {0}', exc)
+            return 0
+
     # Model methods.
 
     def remove(self, delete=False, with_album=True):

test/test_library.py

@@ -1172,6 +1172,22 @@ class ItemReadTest(unittest.TestCase):
             item.read('/thisfiledoesnotexist')
 
 
+class FilesizeTest(unittest.TestCase, TestHelper):
+    def setUp(self):
+        self.setup_beets()
+
+    def tearDown(self):
+        self.teardown_beets()
+
+    def test_filesize(self):
+        item = self.add_item_fixture()
+        self.assertNotEquals(item.filesize, 0)
+
+    def test_nonexistent_file(self):
+        item = beets.library.Item()
+        self.assertEqual(item.filesize, 0)
+
+
 class ParseQueryTest(unittest.TestCase):
     def test_parse_invalid_query_string(self):
         with self.assertRaises(beets.dbcore.InvalidQueryError) as raised: