[Patch #1574068 by Scott Dial] urllib and urllib2 were using
base64.encodestring() for encoding authentication data.
encodestring() can include newlines for very long input, which
produced broken HTTP headers.
2.4 backport candidate, probably.
diff --git a/Misc/NEWS b/Misc/NEWS
index 64fa7bf..57e5ad0 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -110,6 +110,9 @@
- Bug #1576241: fix functools.wraps() to work on built-in functions.
+- Patch #1574068: fix urllib/urllib2 to not insert line breaks when
+ HTTP authentication data was very long.
+
- Fix a bug in traceback.format_exception_only() that led to an error
being raised when print_exc() was called without an exception set.
In version 2.4, this printed "None", restored that behavior.