After much hemming and hawing, we decided to roll back Fred's change.

It breaks Mailman, it was actually documented in the docstring, so it
was an intentional deviation from the usual del semantics.  Let's
document the original behavior in Doc/lib/librfc822.tex.

diff --git a/Lib/rfc822.py b/Lib/rfc822.py
index dcf059c85a3dbdbbfecb3a9802dab9945153a4ea..87219949c322ef4715ce1408ad90660e5ca70eb9 100644 (file)
--- a/Lib/rfc822.py
+++ b/Lib/rfc822.py
@@ -397,11 +397,11 @@ class Message:
     
     def __delitem__(self, name):
         """Delete all occurrences of a specific header, if it is present."""
-        lowname = string.lower(name)
-        if not self.dict.has_key(lowname):
-            raise KeyError, name
-        del self.dict[lowname]
-        name = lowname + ':'
+        name = string.lower(name)
+        if not self.dict.has_key(name):
+            return
+        del self.dict[name]
+        name = name + ':'
         n = len(name)
         list = []
         hit = 0