# HG changeset patch
# User Pierre-Yves David <pierre-yves.david@fb.com>
# Date 2015-09-24 08:00:05
# Node ID 58218b0e6005c8169350b88ce9cff648fe3eeadc
# Parent  cce8ebd3140773c0a95fedb4b3835be55385dbc3

match: remove a mutable default argument

Mutable default arguments are know to the state of California to cause bugs.

diff --git a/mercurial/scmutil.py b/mercurial/scmutil.py
--- a/mercurial/scmutil.py
+++ b/mercurial/scmutil.py
@@ -753,13 +753,15 @@ def expandpats(pats):
         ret.append(kindpat)
     return ret
 
-def matchandpats(ctx, pats=(), opts={}, globbed=False, default='relpath',
+def matchandpats(ctx, pats=(), opts=None, globbed=False, default='relpath',
                  badfn=None):
     '''Return a matcher and the patterns that were used.
     The matcher will warn about bad matches, unless an alternate badfn callback
     is provided.'''
     if pats == ("",):
         pats = []
+    if opts is None:
+        opts = {}
     if not globbed and default == 'relpath':
         pats = expandpats(pats or [])