From df0c21ff46c5c37b6913828ef8c7651f523432f8 Mon Sep 17 00:00:00 2001
From: bsiem <52461103+bsiem@users.noreply.github.com>
Date: Thu, 22 Aug 2019 01:00:39 +0200
Subject: [PATCH] bpo-37482: Fix email address name with encoded words and
 special chars (GH-14561)

Special characters in email address header display names are normally
put within double quotes. However, encoded words (=?charset?x?...?=) are
not allowed withing double quotes. When the header contains a word with
special characters and another word that must be encoded, the first one
must also be encoded.

In the next example, the display name in the From header is quoted and
therefore the comma is allowed; in the To header, the comma is not
within quotes and not encoded, which is not allowed and therefore
rejected by some mail servers.

From: "Foo Bar, France" <foo@example.com>
To: Foo Bar, =?utf-8?q?Espa=C3=B1a?= <foo@example.com>





https://bugs.python.org/issue37482
---
 Lib/email/_header_value_parser.py             |  3 +++
 Lib/test/test_email/test_headerregistry.py    | 24 +++++++++++++++++++
 .../2019-07-09-11-20-21.bpo-37482.auzvev.rst  |  1 +
 3 files changed, 28 insertions(+)
 create mode 100644 Misc/NEWS.d/next/Library/2019-07-09-11-20-21.bpo-37482.auzvev.rst

diff --git a/Lib/email/_header_value_parser.py b/Lib/email/_header_value_parser.py
index ea33bd8eda7..b5003943ab0 100644
--- a/Lib/email/_header_value_parser.py
+++ b/Lib/email/_header_value_parser.py
@@ -2743,6 +2743,9 @@ def _refold_parse_tree(parse_tree, *, policy):
             wrap_as_ew_blocked -= 1
             continue
         tstr = str(part)
+        if part.token_type == 'ptext' and set(tstr) & SPECIALS:
+            # Encode if tstr contains special characters.
+            want_encoding = True
         try:
             tstr.encode(encoding)
             charset = encoding
diff --git a/Lib/test/test_email/test_headerregistry.py b/Lib/test/test_email/test_headerregistry.py
index 4758f4b1c52..38f7ddbf06d 100644
--- a/Lib/test/test_email/test_headerregistry.py
+++ b/Lib/test/test_email/test_headerregistry.py
@@ -1547,6 +1547,30 @@ class TestAddressAndGroup(TestEmailBase):
 
 class TestFolding(TestHeaderBase):
 
+    def test_address_display_names(self):
+        """Test the folding and encoding of address headers."""
+        for name, result in (
+                ('Foo Bar, France', '"Foo Bar, France"'),
+                ('Foo Bar (France)', '"Foo Bar (France)"'),
+                ('Foo Bar, España', 'Foo =?utf-8?q?Bar=2C_Espa=C3=B1a?='),
+                ('Foo Bar (España)', 'Foo Bar =?utf-8?b?KEVzcGHDsWEp?='),
+                ('Foo, Bar España', '=?utf-8?q?Foo=2C_Bar_Espa=C3=B1a?='),
+                ('Foo, Bar [España]', '=?utf-8?q?Foo=2C_Bar_=5BEspa=C3=B1a=5D?='),
+                ('Foo Bär, France', 'Foo =?utf-8?q?B=C3=A4r=2C?= France'),
+                ('Foo Bär <France>', 'Foo =?utf-8?q?B=C3=A4r_=3CFrance=3E?='),
+                (
+                    'Lôrem ipsum dôlôr sit amet, cônsectetuer adipiscing. '
+                    'Suspendisse pôtenti. Aliquam nibh. Suspendisse pôtenti.',
+                    '=?utf-8?q?L=C3=B4rem_ipsum_d=C3=B4l=C3=B4r_sit_amet=2C_c'
+                    '=C3=B4nsectetuer?=\n =?utf-8?q?adipiscing=2E_Suspendisse'
+                    '_p=C3=B4tenti=2E_Aliquam_nibh=2E?=\n Suspendisse =?utf-8'
+                    '?q?p=C3=B4tenti=2E?=',
+                    ),
+                ):
+            h = self.make_header('To', Address(name, addr_spec='a@b.com'))
+            self.assertEqual(h.fold(policy=policy.default),
+                                    'To: %s <a@b.com>\n' % result)
+
     def test_short_unstructured(self):
         h = self.make_header('subject', 'this is a test')
         self.assertEqual(h.fold(policy=policy.default),
diff --git a/Misc/NEWS.d/next/Library/2019-07-09-11-20-21.bpo-37482.auzvev.rst b/Misc/NEWS.d/next/Library/2019-07-09-11-20-21.bpo-37482.auzvev.rst
new file mode 100644
index 00000000000..e09ff63eedc
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2019-07-09-11-20-21.bpo-37482.auzvev.rst
@@ -0,0 +1 @@
+Fix serialization of display name in originator or destination address fields with both encoded words and special chars.