From 1757b8466dc0b5d81319e1100933122f5e1b1a5a Mon Sep 17 00:00:00 2001
From: Araq <rumpf_a@web.de>
Date: Wed, 18 Nov 2015 14:42:13 +0100
Subject: [PATCH] fixes #3546

---
 compiler/vm.nim | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/compiler/vm.nim b/compiler/vm.nim
index afc003452..0e63daf89 100644
--- a/compiler/vm.nim
+++ b/compiler/vm.nim
@@ -255,9 +255,12 @@ proc cleanUpOnException(c: PCtx; tos: PStackFrame):
       nextExceptOrFinally = pc2 + c.code[pc2].regBx - wordExcess
       inc pc2
     while c.code[pc2].opcode == opcExcept:
-      let exceptType = c.types[c.code[pc2].regBx-wordExcess].skipTypes(
+      let excIndex = c.code[pc2].regBx-wordExcess
+      let exceptType = if excIndex > 0: c.types[excIndex].skipTypes(
                           abstractPtrs)
-      if inheritanceDiff(exceptType, raisedType) <= 0:
+                       else: nil
+      #echo typeToString(exceptType), " ", typeToString(raisedType)
+      if exceptType.isNil or inheritanceDiff(exceptType, raisedType) <= 0:
         # mark exception as handled but keep it in B for
         # the getCurrentException() builtin:
         c.currentExceptionB = c.currentExceptionA