#11401: handle headers with no value.
diff --git a/Lib/email/header.py b/Lib/email/header.py
index 43220df..da739d5 100644
--- a/Lib/email/header.py
+++ b/Lib/email/header.py
@@ -304,7 +304,7 @@
self._continuation_ws, splitchars)
for string, charset in self._chunks:
lines = string.splitlines()
- formatter.feed(lines[0], charset)
+ formatter.feed(lines[0] if lines else '', charset)
for line in lines[1:]:
formatter.newline()
if charset.header_encoding is not None:
diff --git a/Lib/email/test/test_email.py b/Lib/email/test/test_email.py
index 6a88b16..4268a25 100644
--- a/Lib/email/test/test_email.py
+++ b/Lib/email/test/test_email.py
@@ -3296,6 +3296,13 @@
h = Header('文', charset='shift_jis')
self.assertEqual(h.encode(), '=?iso-2022-jp?b?GyRCSjgbKEI=?=')
+ def test_flatten_header_with_no_value(self):
+ # Issue 11401 (regression from email 4.x) Note that the space after
+ # the header doesn't reflect the input, but this is also the way
+ # email 4.x behaved. At some point it would be nice to fix that.
+ msg = email.message_from_string("EmptyHeader:")
+ self.assertEqual(str(msg), "EmptyHeader: \n\n")
+
# Test RFC 2231 header parameters (en/de)coding
diff --git a/Misc/NEWS b/Misc/NEWS
index beb6ec1..58eea2d 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -40,6 +40,9 @@
Library
-------
+- Issue #11401: fix handling of headers with no value; this fixes a regression
+ relative to Python2 and the result is now the same as it was in Python2.
+
- Issue #9298: base64 bodies weren't being folded to line lengths less than 78,
which was a regression relative to Python2. Unlike Python2, the last line
of the folded body now ends with a carriage return.