[PATCH 1 of 2] status: fix default value of status struct

[Yuya Nishihara]

# HG changeset patch
# User Yuya Nishihara <yuya at tcha.org>
# Date 1574344343 -32400
#      Thu Nov 21 22:52:23 2019 +0900
# Node ID c19643244c5c9952ff624663e5232c5071d568da
# Parent  835d415c5a17258e2cf11e9fcd650441690dfbd4
status: fix default value of status struct

The default argument isn't overloaded. Before, the default constructor would
create a struct having 7 list type objects.

diff --git a/mercurial/scmutil.py b/mercurial/scmutil.py
--- a/mercurial/scmutil.py
+++ b/mercurial/scmutil.py
@@ -70,13 +70,13 @@ class status(object):
     relevant to the working copy.
     '''
 
-    modified = attr.ib(default=list)
-    added = attr.ib(default=list)
-    removed = attr.ib(default=list)
-    deleted = attr.ib(default=list)
-    unknown = attr.ib(default=list)
-    ignored = attr.ib(default=list)
-    clean = attr.ib(default=list)
+    modified = attr.ib(default=attr.Factory(list))
+    added = attr.ib(default=attr.Factory(list))
+    removed = attr.ib(default=attr.Factory(list))
+    deleted = attr.ib(default=attr.Factory(list))
+    unknown = attr.ib(default=attr.Factory(list))
+    ignored = attr.ib(default=attr.Factory(list))
+    clean = attr.ib(default=attr.Factory(list))
 
     def __iter__(self):
         yield self.modified