From 96e9bf45e8978e5f237460ac93e6f03c82cba06d Mon Sep 17 00:00:00 2001
From: Barry Warsaw <barry@python.org>
Date: Mon, 12 Jul 1999 18:37:02 +0000
Subject: [PATCH] AddrlistClass.getaddress(): when parsing `:'s, in the loop,
 watch out for gotonext() pushing self.pos past the end of the string.  This
 can happen if the message has a To field like "To: :" and you call
 msg.getaddrlist('to').

---
 Lib/rfc822.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/Lib/rfc822.py b/Lib/rfc822.py
index 662703beca3..7030ee7cb31 100644
--- a/Lib/rfc822.py
+++ b/Lib/rfc822.py
@@ -553,10 +553,11 @@ class AddrlistClass:
             # address is a group
             returnlist = []
             
+            fieldlen = len(self.field)
             self.pos = self.pos + 1
             while self.pos < len(self.field):
                 self.gotonext()
-                if self.field[self.pos] == ';':
+                if self.pos < fieldlen and self.field[self.pos] == ';':
                     self.pos = self.pos + 1
                     break
                 returnlist = returnlist + self.getaddress()