From 90a5edfa6dc6ac781ddacbba07c8e10bd9aee871 Mon Sep 17 00:00:00 2001
From: Matthew Baulch <baulch.matt@gmail.com>
Date: Mon, 11 Jul 2016 15:10:54 +1000
Subject: Fix #4422: Reset queue element on pop. Prevent NimVM confusion. Help
 GC.

---
 lib/pure/collections/queues.nim | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/lib/pure/collections/queues.nim b/lib/pure/collections/queues.nim
index 911816518..399e4d413 100644
--- a/lib/pure/collections/queues.nim
+++ b/lib/pure/collections/queues.nim
@@ -152,11 +152,13 @@ proc add*[T](q: var Queue[T], item: T) =
   q.data[q.wr] = item
   q.wr = (q.wr + 1) and q.mask
 
+proc default[T](t: typedesc[T]): T {.inline.} = discard
 proc pop*[T](q: var Queue[T]): T {.inline, discardable.} =
   ## Remove and returns the first (oldest) element of the queue `q`.
   emptyCheck(q)
   dec q.count
   result = q.data[q.rd]
+  q.data[q.rd] = default(type(result))
   q.rd = (q.rd + 1) and q.mask
 
 proc enqueue*[T](q: var Queue[T], item: T) =
-- 
cgit 1.4.1-2-gfad0