From 53566f716501fe906b8b2aa4ce050be5d6eb0364 Mon Sep 17 00:00:00 2001
From: Araq <rumpf_a@web.de>
Date: Mon, 30 Jul 2018 23:27:01 +0200
Subject: fixes #7833; still to-do: fix setLen

---
 lib/system/gc.nim | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

(limited to 'lib/system')

diff --git a/lib/system/gc.nim b/lib/system/gc.nim
index 425963f3f..74ac68eea 100644
--- a/lib/system/gc.nim
+++ b/lib/system/gc.nim
@@ -548,7 +548,10 @@ proc growObj(old: pointer, newsize: int, gch: var GcHeap): pointer =
   gcTrace(res, csAllocated)
   track("growObj old", ol, 0)
   track("growObj new", res, newsize)
-  when reallyDealloc:
+  when defined(nimIncrSeqV3):
+    # since we steal the old seq's contents, we set the old length to 0.
+    cast[PGenericSeq](old).len = 0
+  elif reallyDealloc:
     sysAssert(allocInv(gch.region), "growObj before dealloc")
     if ol.refcount shr rcShift <=% 1:
       # free immediately to save space:
-- 
cgit 1.4.1-2-gfad0