mercurial/revset.py

--- a/mercurial/revset.py	Mon Jan 05 22:18:55 2015 -0800
+++ b/mercurial/revset.py	Sat Jan 10 21:31:59 2015 +0900
@@ -2913,10 +2913,10 @@
             return abs(self._end - self._start) - count
 
     def isascending(self):
-        return self._start <= self._end
+        return self._ascending
 
     def isdescending(self):
-        return self._start >= self._end
+        return not self._ascending
 
     def first(self):
         if self._ascending: