Queries with \ are path queries on Windows

beets/library.py

@@ -85,8 +85,14 @@ class PathQuery(dbcore.FieldQuery):
         colon = query_part.find(':')
         if colon != -1:
             query_part = query_part[:colon]
-        return (os.sep in query_part and
-                os.path.exists(syspath(normpath(query_part))))
+
+        # Test both `sep` and `altsep` (i.e., both slash and backslash on
+        # Windows).
+        return (
+            (os.sep in query_part or
+             (os.altsep and os.altsep in query_part)) and
+            os.path.exists(syspath(normpath(query_part)))
+        )
 
     def match(self, item):
         path = item.path if self.case_sensitive else item.path.lower()

docs/changelog.rst

@@ -6,6 +6,11 @@ Changelog
 
 Changelog goes here!
 
+Some fixes for Windows:
+
+* Queries are now detected as paths when they contain backslashes (in
+  addition to forward slashes). This only applies on Windows.
+
 
 1.3.18 (May 31, 2016)
 ---------------------

test/test_query.py

@@ -569,7 +569,10 @@ class PathQueryTest(_common.LibTestCase, TestHelper, AssertsMixin):
     @patch('beets.library.os')
     def test_path_sep_detection(self, mock_os):
         mock_os.sep = '/'
+        mock_os.altsep = None
+        mock_os.path.exists = lambda p: True
         is_path = beets.library.PathQuery.is_path_query
+
         self.assertTrue(is_path('/foo/bar'))
         self.assertTrue(is_path('foo/bar'))
         self.assertTrue(is_path('foo/'))