# HG changeset patch
# User Jun Wu <quark@fb.com>
# Date 2017-10-03 19:00:07
# Node ID 0efdfb57b05cffb26b3f306f08c9424e0481b776
# Parent  40b6d25ed2d525938ad666e6a0e13f663a4cbcef

config: add a missing preparewrite() call

Thanks Yuya for pointing this out in D808.

Differential Revision: https://phab.mercurial-scm.org/D924

diff --git a/mercurial/config.py b/mercurial/config.py
--- a/mercurial/config.py
+++ b/mercurial/config.py
@@ -177,6 +177,7 @@ class config(object):
                 if sections and section not in sections:
                     continue
                 if self.get(section, name) is not None:
+                    self._data[section] = self._data[section].preparewrite()
                     del self._data[section][name]
                 self._unset.append((section, name))
                 continue