Fixed #12422 -- Don't override global email charset behavior for utf-8.

Thanks simonb for the report, Claude Paroz and Susan Tan for their work
on a fix.

1 files changed, 12 insertions, 2 deletions

diff --git a/django/core/mail/message.py b/django/core/mail/message.py
index 9796e59260..a24817ac90 100644
--- a/django/core/mail/message.py
+++ b/django/core/mail/message.py
@@ -22,7 +22,8 @@ from django.utils import six
 
 # Don't BASE64-encode UTF-8 messages so that we avoid unwanted attention from
 # some spam filters.
-Charset.add_charset('utf-8', Charset.SHORTEST, None, 'utf-8')
+utf8_charset = Charset.Charset('utf-8')
+utf8_charset.body_encoding = None  # Python defaults to BASE64
 
 # Default MIME type to use on attachments (if it is not explicitly given
 # and cannot be guessed).
@@ -145,7 +146,16 @@ class SafeMIMEText(MIMEText):
 
     def __init__(self, text, subtype, charset):
         self.encoding = charset
-        MIMEText.__init__(self, text, subtype, charset)
+        if charset == 'utf-8':
+            # Unfortunately, Python doesn't support setting a Charset instance
+            # as MIMEText init parameter (http://bugs.python.org/issue16324).
+            # We do it manually and trigger re-encoding of the payload.
+            MIMEText.__init__(self, text, subtype, None)
+            del self['Content-Transfer-Encoding']
+            self.set_payload(text, utf8_charset)
+            self.replace_header('Content-Type', 'text/%s; charset="%s"' % (subtype, charset))
+        else:
+            MIMEText.__init__(self, text, subtype, charset)
 
     def __setitem__(self, name, val):
         name, val = forbid_multi_line_headers(name, val, self.encoding)