From 594f8019d1b20326bcd25846ab3866adca61b782 Mon Sep 17 00:00:00 2001
From: Jean-Paul Calderone <exarkun@twistedmatrix.com>
Date: Wed, 18 Nov 2020 18:29:36 -0500
Subject: [PATCH] Better support Windows here

---
 src/allmydata/util/configutil.py | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/src/allmydata/util/configutil.py b/src/allmydata/util/configutil.py
index 8063ba449..ea64e1704 100644
--- a/src/allmydata/util/configutil.py
+++ b/src/allmydata/util/configutil.py
@@ -20,6 +20,10 @@ from configparser import ConfigParser
 
 import attr
 
+from twisted.python.runtime import (
+    platform,
+)
+
 
 class UnknownConfigError(Exception):
     """
@@ -73,6 +77,10 @@ def write_config(tahoe_cfg, config):
     # with ConfigParser.write.
     with open(tmp.path, "wt") as fp:
         config.write(fp)
+    # Windows doesn't have atomic overwrite semantics for moveTo.  Thus we end
+    # up slightly less than atomic.
+    if platform.isWindows():
+        tahoe_cfg.remove()
     tmp.moveTo(tahoe_cfg)
 
 def validate_config(fname, cfg, valid_config):