diff -r adf4ec7e6f60 -r 4d27c30d58d5 mercurial/revset.py
--- a/mercurial/revset.py	Fri Mar 14 10:24:09 2014 -0700
+++ b/mercurial/revset.py	Tue Mar 11 17:25:53 2014 -0700
@@ -2283,7 +2283,7 @@
         return lazyset(self, lambda r: r not in x)
 
     def __add__(self, x):
-        return lazyset(_addset(self, x))
+        return _addset(self, x)
 
     def __nonzero__(self):
         for r in self:
@@ -2347,6 +2347,14 @@
         return orderedlazyset(self, lambda r: r not in x,
                 ascending=self._ascending)
 
+    def __add__(self, x):
+        kwargs = {}
+        if self.isascending() and x.isascending():
+            kwargs['ascending'] = True
+        if self.isdescending() and x.isdescending():
+            kwargs['ascending'] = False
+        return _addset(self, x, **kwargs)
+
     def sort(self, reverse=False):
         if reverse:
             if self._ascending:
@@ -2694,7 +2702,12 @@
             return orderedlazyset(self, lambda r: r not in x, ascending=False)
 
     def __add__(self, x):
-        return lazyset(_addset(self, x))
+        kwargs = {}
+        if self.isascending() and x.isascending():
+            kwargs['ascending'] = True
+        if self.isdescending() and x.isdescending():
+            kwargs['ascending'] = False
+        return _addset(self, x, **kwargs)
 
     def __len__(self):
         if not self._hiddenrevs: