From ca0b16fd337d15abd2ea873a06dbca85777d886e Mon Sep 17 00:00:00 2001
From: Andreas Rumpf <rumpf_a@web.de>
Date: Thu, 26 Jan 2017 15:20:24 +0100
Subject: [PATCH] newException supports setting of the 'parent' field

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

diff --git a/lib/system.nim b/lib/system.nim
index 1e6d2dff4a..86edccfe99 100644
--- a/lib/system.nim
+++ b/lib/system.nim
@@ -2554,13 +2554,14 @@ else:
   proc debugEcho*(x: varargs[expr, `$`]) {.magic: "Echo", noSideEffect,
                                              tags: [], raises: [].}
 
-template newException*(exceptn: typedesc, message: string): expr =
+template newException*(exceptn: typedesc, message: string; parentException: ref Exception = nil): expr =
   ## creates an exception object of type ``exceptn`` and sets its ``msg`` field
   ## to `message`. Returns the new exception object.
   var
     e: ref exceptn
   new(e)
   e.msg = message
+  e.parent = parentException
   e
 
 when hostOS == "standalone":