db/message: handle text MIME with invalid charsets

1 files changed, 17 insertions, 0 deletions

diff --git a/alot/db/message.py b/alot/db/message.py
index 29ca11dc..9d5bb958 100644
--- a/alot/db/message.py
+++ b/alot/db/message.py
@@ -2,6 +2,7 @@
 # This file is released under the GNU GPL, version 3 or a later revision.
 # For further details see the COPYING file
 
+import codecs
 import email
 import email.charset as charset
 import email.policy
@@ -125,9 +126,25 @@ class _MimeTree:
                 self.attachment = Attachment(data, self.content_type,
                                              fn, part.get_params())
 
+            if self.content_maintype == 'text':
+                self._fixup_charset()
+
     def __str__(self):
         return 'MimePart(%s)' % self.content_type
 
+    def _fixup_charset(self):
+        """
+        If a text MIME part declares an invalid charset, replace it with UTF-8
+        """
+        charset = self._part.get_param('charset')
+        if charset is None:
+            return
+
+        try:
+            codecs.lookup(charset)
+        except LookupError:
+            self._part.set_param('charset', 'utf-8')
+
     def render_str(self, alt_preference = None):
         if self.children is not None:
             if self.is_alternative and len(self.children) > 0: