# HG changeset patch
# User Martijn Pieters <mjpieters@fb.com>
# Date 2017-03-12 19:56:12
# Node ID d30fb3de4b403209b09c14e4ccaee5fb80accbbf
# Parent  7548522742b5f4f9f5c0881ae4a2783ecda2f969

config: avoid using a mutable default

Nothing *currently* mutates this list, but the moment something does it'll be
shared between all config instances. Avoid this eventuality.

diff --git a/mercurial/config.py b/mercurial/config.py
--- a/mercurial/config.py
+++ b/mercurial/config.py
@@ -18,11 +18,11 @@ from . import (
 )
 
 class config(object):
-    def __init__(self, data=None, includepaths=[]):
+    def __init__(self, data=None, includepaths=None):
         self._data = {}
         self._source = {}
         self._unset = []
-        self._includepaths = includepaths
+        self._includepaths = includepaths or []
         if data:
             for k in data._data:
                 self._data[k] = data[k].copy()