From dd0b90a367f4c04a0d2b210f59a29a2eb2200fec Mon Sep 17 00:00:00 2001
From: Alexandre Vassalotti <alexandre@peadrop.com>
Date: Fri, 12 Jun 2009 21:20:23 +0000
Subject: [PATCH] Fix issue #6127: Make universal newlines mode of io.StringIO
 not duplicate newlines under Windows (see also issue #5265 and #5645).

---
 Lib/io.py | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/Lib/io.py b/Lib/io.py
index 320a4b9b5f..72f7d8c5ea 100644
--- a/Lib/io.py
+++ b/Lib/io.py
@@ -1852,6 +1852,10 @@ class StringIO(TextIOWrapper):
                                        encoding=encoding,
                                        errors=errors,
                                        newline=newline)
+        # Issue #5645: make universal newlines semantics the same as in the
+        # C version, even under Windows.
+        if newline is None:
+            self._writetranslate = False
         if initial_value:
             if not isinstance(initial_value, unicode):
                 initial_value = unicode(initial_value)
-- 
2.50.1