Factor out shlex.split workaround

beets/library.py

@@ -19,7 +19,6 @@ from __future__ import (division, absolute_import, print_function,
 
 import os
 import sys
-import shlex
 import unicodedata
 import time
 import re
@@ -1139,13 +1138,8 @@ def parse_query_string(s, model_cls):
     The string is split into components using shell-like syntax.
     """
     assert isinstance(s, unicode), "Query is not unicode: {0!r}".format(s)
-
-    # A bug in Python < 2.7.3 prevents correct shlex splitting of
-    # Unicode strings.
-    # http://bugs.python.org/issue6988
-    s = s.encode('utf8')
     try:
-        parts = [p.decode('utf8') for p in shlex.split(s)]
+        parts = util.shlex_split(s)
     except ValueError as exc:
         raise dbcore.InvalidQueryError(s, exc)
     return parse_query_parts(parts, model_cls)

beets/util/__init__.py

@@ -749,6 +749,26 @@ def editor_command():
     return open_anything()
 
 
+def shlex_split(s):
+    """Split a Unicode or bytes string according to shell lexing rules.
+
+    Raise `ValueError` if the string is not a well-formed shell string.
+    This is a workaround for a bug in some versions of Python.
+    """
+    if isinstance(s, bytes):
+        # Shlex works fine.
+        return shlex.split(s)
+
+    elif isinstance(s, unicode):
+        # Work around a Python bug.
+        # http://bugs.python.org/issue6988
+        bs = s.encode('utf8')
+        return [c.decode('utf8') for c in shlex.split(bs)]
+
+    else:
+        raise TypeError('shlex_split called with non-string')
+
+
 def interactive_open(targets, command):
     """Open the files in `targets` by `exec`ing a new `command`, given
     as a Unicode string. (The new program takes over, and Python
@@ -757,15 +777,12 @@ def interactive_open(targets, command):
     Can raise `OSError`.
     """
     # Split the command string into its arguments.
-    command = command.encode('utf8')
     try:
-        command = [c.decode('utf8')
-                   for c in shlex.split(command)]
+        command = shlex_split(command)
     except ValueError:  # Malformed shell tokens.
         command = [command]
     command.insert(0, command[0])  # for argv[0]
 
-    # Add the explicit arguments.
     command += targets
 
     return os.execlp(*command)