From 23386ce96e1828c6b8f4dc5eee50467d8cf286ab Mon Sep 17 00:00:00 2001
From: Michael Ortmann <41313082+michaelortmann@users.noreply.github.com>
Date: Mon, 13 Feb 2023 00:50:05 +0000
Subject: [PATCH] Fix load of null pointer

Found by: 0_o I am EMPTY, mister EMPTY, ZarTek-Creole
Patch by: michaelortmann
Fixes: #1389
---
 src/net.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/net.c b/src/net.c
index 7539500fe..30e1f4cb8 100644
--- a/src/net.c
+++ b/src/net.c
@@ -1700,6 +1700,12 @@ char *traced_natip(ClientData cd, Tcl_Interp *irp, EGG_CONST char *name1,
   int r;
   struct in_addr ia;
 
+  /* Recover trace in case of unset. */
+  if (flags & TCL_TRACE_DESTROYED) {
+    Tcl_TraceVar2(irp, name1, name2, TCL_GLOBAL_ONLY|TCL_TRACE_WRITES|TCL_TRACE_UNSETS, traced_natip, cd);
+    return NULL;
+  }
+
   value = Tcl_GetVar2(irp, name1, name2, TCL_GLOBAL_ONLY);
   if (*value) {
     r = inet_pton(AF_INET, value, &ia);