* Lib/linecache.py: don't crash on empty filename
	* Lib/macpath.py: don't return trailing colon for dirname()
	(XXX won't do for volume names -- but otherwise glob(':*:*.py')
	loops forever)
	* Lib/traceback.py: print SyntaxError correctly
	* Lib/stat.py: moved to posixstat.py; added macstat.py which has
	the constants for the Mac; and created new stat.py which includes
	the right one
	* Lib/urllib.py: fix caching bug (by disabling the cache)
diff --git a/Lib/linecache.py b/Lib/linecache.py
index b981869..f5726e9 100644
--- a/Lib/linecache.py
+++ b/Lib/linecache.py
@@ -59,7 +59,7 @@
 def updatecache(filename):
 	if cache.has_key(filename):
 		del cache[filename]
-	if filename[0] + filename[-1] == '<>':
+	if not filename or filename[0] + filename[-1] == '<>':
 		return []
 	fullname = filename
 	try: