From e210b049e99b3a42933f099f7fe0f834bcba1cf3 Mon Sep 17 00:00:00 2001
From: Araq <rumpf_a@web.de>
Date: Fri, 14 Feb 2014 02:29:19 +0100
Subject: fixes #712

---
 compiler/sem.nim | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

(limited to 'compiler')

diff --git a/compiler/sem.nim b/compiler/sem.nim
index 845d4ae71..140687721 100644
--- a/compiler/sem.nim
+++ b/compiler/sem.nim
@@ -120,7 +120,8 @@ proc commonType*(x, y: PType): PType =
     if a.kind == tyObject and b.kind == tyObject:
       result = commonSuperclass(a, b)
       # this will trigger an error later:
-      if result.isNil: return x
+      if result.isNil or result == a: return x
+      if result == b: return y
       if k != tyNone:
         let r = result
         result = newType(k, r.owner)
-- 
cgit 1.4.1-2-gfad0