gh-91400: make sure email parsing dont unquote realnames with spaces

Lib/email/utils.py

@@ -40,7 +40,9 @@
 CRLF = '\r\n'
 TICK = "'"
 
-specialsre = re.compile(r'[][\\()<>@,:;".]')
+# These are used by formataddr() to understand what characters require a name
+# field to be quoted and what characters within that must be \escaped.
+specialsre = re.compile(r'[][\\()<>@,:;". ]')
 escapesre = re.compile(r'[\\"]')
 
 

Lib/test/test_email/test_email.py

@@ -3227,7 +3227,7 @@ def test_parseaddr_multiple_domains(self):
     def test_noquote_dump(self):
         self.assertEqual(
             utils.formataddr(('A Silly Person', 'person@dom.ain')),
-            'A Silly Person <person@dom.ain>')
+            '"A Silly Person" <person@dom.ain>')
 
     def test_escape_dump(self):
         self.assertEqual(
@@ -3248,6 +3248,12 @@ def test_escape_backslashes(self):
         b = 'person@dom.ain'
         self.assertEqual(utils.parseaddr(utils.formataddr((a, b))), (a, b))
 
+    def test_parseaddr_formataddr_inverse(self):
+        # gh-91400
+        identity = '"foo  bar" <foo@example.com>'
+        single = utils.formataddr(utils.parseaddr(identity))
+        self.assertEqual(identity, single)
+
     def test_quotes_unicode_names(self):
         # issue 1690608.  email.utils.formataddr() should be rfc2047 aware.
         name = "H\u00e4ns W\u00fcrst"

Misc/NEWS.d/next/Library/2022-05-10-21-46-28.gh-issue-91400.usUzm_.rst

@@ -0,0 +1,2 @@
+Make :func:`email.utils.formataddr` "quote" the name portion of an email address if
+it contains spaces.