parsedate_tz(): If data is false, return None. Fixes bug #478115,

IndexError when a Date: field exists with an empty value.

diff --git a/Lib/rfc822.py b/Lib/rfc822.py
index 430e6372f0fd53965fe56c482a5e1cc31033788e..00199495885e012925d50c53224658fb729b0659 100644 (file)
--- a/Lib/rfc822.py
+++ b/Lib/rfc822.py
@@ -858,6 +858,8 @@ def parsedate_tz(data):
 
     Accounts for military timezones.
     """
+    if not data:
+        return None
     data = data.split()
     if data[0][-1] in (',', '.') or data[0].lower() in _daynames:
         # There's a dayname here. Skip it