Merge branch 'kali/bug/several-mime-fixes' into develop

1 files changed, 8 insertions, 7 deletions

diff --git a/src/leap/mail/imap/messages.py b/src/leap/mail/imap/messages.py
index 02aac2e..4c6f10d 100644
--- a/src/leap/mail/imap/messages.py
+++ b/src/leap/mail/imap/messages.py
@@ -22,7 +22,7 @@ from twisted.mail import imap4
 from twisted.internet import defer
 from zope.interface import implements
 
-from leap.mail.utils import find_charset
+from leap.mail.utils import find_charset, CaseInsensitiveDict
 
 
 logger = logging.getLogger(__name__)
@@ -228,13 +228,13 @@ def _format_headers(headers, negate, *names):
     # default to most likely standard
     charset = find_charset(headers, "utf-8")
 
-    _headers = dict()
-    for key, value in headers.items():
-        # twisted imap server expects *some* headers to be lowercase
-        # We could use a CaseInsensitiveDict here...
-        if key.lower() == "content-type":
-            key = key.lower()
+    # We will return a copy of the headers dictionary that
+    # will allow case-insensitive lookups. In some parts of the twisted imap
+    # server code the keys are expected to be in lower case, and in this way
+    # we avoid having to convert them.
 
+    _headers = CaseInsensitiveDict()
+    for key, value in headers.items():
         if not isinstance(key, str):
             key = key.encode(charset, 'replace')
         if not isinstance(value, str):
@@ -247,4 +247,5 @@ def _format_headers(headers, negate, *names):
         # filter original dict by negate-condition
         if cond(key):
             _headers[key] = value
+
     return _headers