# HG changeset patch
# User Paul Boddie <paul@boddie.org.uk>
# Date 1302472329 -7200
# Node ID 1e30e9b62ffc01342e36d0d2faadafff8d6fef66
# Parent  bcf9bea7d4e4722479f958bb6d3f1a769563372a
Fixed ambiguity testing of open-ended timespans.

diff -r bcf9bea7d4e4 -r 1e30e9b62ffc EventAggregatorSupport.py
--- a/EventAggregatorSupport.py	Sun Apr 10 18:28:16 2011 +0200
+++ b/EventAggregatorSupport.py	Sun Apr 10 23:52:09 2011 +0200
@@ -1558,7 +1558,7 @@
 
         # NOTE: Should perhaps catch ambiguous time problems elsewhere.
 
-        if self.ambiguous() and start > end:
+        if self.ambiguous() and self.start is not None and self.end is not None and start > end:
             self.start, self.end = end, start
 
     def __repr__(self):
@@ -1574,7 +1574,7 @@
         return self.start, self.end
 
     def ambiguous(self):
-        return self.start.ambiguous() or self.end.ambiguous()
+        return self.start is not None and self.start.ambiguous() or self.end is not None and self.end.ambiguous()
 
     def convert(self, resolution):
         return Timespan(*map(self._get_converter(resolution), self.as_limits()))