diff mercurial/ui.py @ 33150:77e666f943a6

configitems: support callable as a default value

Yuya pointed out that using mutable value as the default could be problematic.
To work around this we now support callable object as default value. This
allows for creating new mutable objects on demand when needed.

--- a/mercurial/ui.py	Tue Jun 27 02:06:15 2017 +0200
+++ b/mercurial/ui.py	Wed Jun 28 13:50:20 2017 +0200
@@ -455,6 +455,8 @@
             if default is _unset:
                 if item is None:
                     value = default
+                elif callable(item.default):
+                    value = item.default()
                 else:
                     value = item.default
             elif item is not None: