From ba20fa3939c1505866d715a5a1a43f61a4f8de17 Mon Sep 17 00:00:00 2001
From: Alejandro Colomar <alx.manpages@gmail.com>
Date: Tue, 17 May 2022 11:18:58 +0200
Subject: [PATCH] Fixed memcpy(dest, NULL, 0) Undefined Behavior.

nxt_str_null() setted the loc.start pointer to NULL, which was
being passed to memcpy(3) through nxt_debug().  That caused
Undefined Behavior, so we now pass an empty string.
---
 src/nxt_http_return.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/nxt_http_return.c b/src/nxt_http_return.c
index e3dd02ad..8832941f 100644
--- a/src/nxt_http_return.c
+++ b/src/nxt_http_return.c
@@ -80,7 +80,7 @@ nxt_http_return(nxt_task_t *task, nxt_http_request_t *r,
     conf = action->u.conf;
 
     if (conf->location == NULL) {
-        nxt_str_null(&loc);
+        nxt_str_set(&loc, "");
 
     } else {
         nxt_var_raw(conf->location, &loc);