From b59c657be3e9049f936c0c6cc6083a41a343737a Mon Sep 17 00:00:00 2001
From: Andreas Rumpf <rumpf_a@web.de>
Date: Sat, 10 Dec 2022 16:21:43 +0100
Subject: [PATCH] fixes #21062 (#21068)

---
 lib/system/alloc.nim | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/lib/system/alloc.nim b/lib/system/alloc.nim
index 9c8f70c11224..a7db3704bbaf 100644
--- a/lib/system/alloc.nim
+++ b/lib/system/alloc.nim
@@ -787,8 +787,9 @@ when defined(gcDestructors):
     while it != nil:
       if maxIters == 0:
         let rest = it.next.loada
-        it.next.storea nil
-        addToSharedFreeList(c, rest)
+        if rest != nil:
+          it.next.storea nil
+          addToSharedFreeList(c, rest)
         break
       inc x, size
       it = it.next.loada