From 541c2a3fecd7b1f3e6d9dc7e23a7583000cb68f1 Mon Sep 17 00:00:00 2001
From: cooldome <ariabushenko@bk.ru>
Date: Thu, 28 Jun 2018 09:21:09 +0100
Subject: [PATCH] one more attempt

---
 compiler/ast.nim | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/compiler/ast.nim b/compiler/ast.nim
index a52cf21445..6ad8d78f56 100644
--- a/compiler/ast.nim
+++ b/compiler/ast.nim
@@ -1692,12 +1692,14 @@ proc isException*(t: PType): bool =
   # check if `y` is object type and it inherits from Exception
   assert(t != nil)
 
+  if t.kind notin {tyObject, tyGenericInst}:
+    return false
+
   var base = t
-  while base != nil and base.kind in {tyRef, tyObject, tyGenericInst, tyAlias}:
+  while base != nil:
     if base.sym != nil and base.sym.magic == mException:
       return true
-    if base.len == 0: break
-    else: base = base.lastSon
+    base = base.lastSon
   return false
 
 proc isImportedException*(t: PType; conf: ConfigRef): bool =