#2676: email/message.py [Message.get_content_type]: Trivial regex hangs on pathological input
diff --git a/Lib/email/message.py b/Lib/email/message.py
index 287232b..e44217b 100644
--- a/Lib/email/message.py
+++ b/Lib/email/message.py
@@ -19,18 +19,22 @@
SEMISPACE = '; '
-# Regular expression used to split header parameters. BAW: this may be too
-# simple. It isn't strictly RFC 2045 (section 5.1) compliant, but it catches
-# most headers found in the wild. We may eventually need a full fledged
-# parser eventually.
-paramre = re.compile(r'\s*;\s*')
# Regular expression that matches `special' characters in parameters, the
# existance of which force quoting of the parameter value.
tspecials = re.compile(r'[ \(\)<>@,;:\\"/\[\]\?=]')
-
# Helper functions
+def _splitparam(param):
+ # Split header parameters. BAW: this may be too simple. It isn't
+ # strictly RFC 2045 (section 5.1) compliant, but it catches most headers
+ # found in the wild. We may eventually need a full fledged parser
+ # eventually.
+ a, sep, b = param.partition(';')
+ if not sep:
+ return a.strip(), None
+ return a.strip(), b.strip()
+
def _formatparam(param, value=None, quote=True):
"""Convenience function to format and return a key=value pair.
@@ -436,7 +440,7 @@
if value is missing:
# This should have no parameters
return self.get_default_type()
- ctype = paramre.split(value)[0].lower().strip()
+ ctype = _splitparam(value)[0].lower()
# RFC 2045, section 5.2 says if its invalid, use text/plain
if ctype.count('/') != 1:
return 'text/plain'