From 4d4a993e7f47354b3de80c3f307a7a8d2b50e99b Mon Sep 17 00:00:00 2001
From: Andreas Rumpf <rumpf_a@web.de>
Date: Fri, 26 Aug 2016 13:51:58 +0200
Subject: [PATCH] fixes #2865

---
 compiler/types.nim | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/compiler/types.nim b/compiler/types.nim
index ca2718ed16..c06e906e56 100644
--- a/compiler/types.nim
+++ b/compiler/types.nim
@@ -653,7 +653,14 @@ proc lengthOrd(t: PType): BiggestInt =
   case t.kind
   of tyInt64, tyInt32, tyInt: result = lastOrd(t)
   of tyDistinct, tyConst, tyMutable: result = lengthOrd(t.sons[0])
-  else: result = lastOrd(t) - firstOrd(t) + 1
+  else:
+    let last = lastOrd t
+    let first = firstOrd t
+    # XXX use a better overflow check here:
+    if last == high(BiggestInt) and first <= 0:
+      result = last
+    else:
+      result = lastOrd(t) - firstOrd(t) + 1
 
 # -------------- type equality -----------------------------------------------