From f8047c3e3cc43a792cb89b1047559fc1c2bac1f2 Mon Sep 17 00:00:00 2001
From: Tanguy <tanguy@status.im>
Date: Tue, 7 Dec 2021 18:01:22 +0100
Subject: [PATCH] fix #19193 (#19195) [backport:1.2]

(cherry picked from commit cd592ed85ba3bf440d7b24a4bc5b117d1a5f8725)
---
 compiler/cgen.nim | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/compiler/cgen.nim b/compiler/cgen.nim
index 20bf25d934da..458605d1eb03 100644
--- a/compiler/cgen.nim
+++ b/compiler/cgen.nim
@@ -439,8 +439,14 @@ proc constructLoc(p: BProc, loc: var TLoc, isTemp = false) =
   if optSeqDestructors in p.config.globalOptions and skipTypes(typ, abstractInst + {tyStatic}).kind in {tyString, tySequence}:
     linefmt(p, cpsStmts, "$1.len = 0; $1.p = NIM_NIL;$n", [rdLoc(loc)])
   elif not isComplexValueType(typ):
-    linefmt(p, cpsStmts, "$1 = ($2)0;$n", [rdLoc(loc),
-      getTypeDesc(p.module, typ, mapTypeChooser(loc))])
+    if containsGarbageCollectedRef(loc.t):
+      var nilLoc: TLoc
+      initLoc(nilLoc, locTemp, loc.lode, OnStack)
+      nilLoc.r = rope("NIM_NIL")
+      genRefAssign(p, loc, nilLoc)
+    else:
+      linefmt(p, cpsStmts, "$1 = ($2)0;$n", [rdLoc(loc),
+        getTypeDesc(p.module, typ, mapTypeChooser(loc))])
   else:
     if not isTemp or containsGarbageCollectedRef(loc.t):
       # don't use nimZeroMem for temporary values for performance if we can