mercurial/revset.py

--- a/mercurial/revset.py	Sun May 10 05:11:13 2015 -0700
+++ b/mercurial/revset.py	Mon Mar 30 20:56:37 2015 +0900
@@ -360,7 +360,7 @@
 
 def orset(repo, subset, x, y):
     xl = getset(repo, subset, x)
-    yl = getset(repo, subset - xl, y)
+    yl = getset(repo, subset, y)
     return xl + yl
 
 def notset(repo, subset, x):