From ffbc9981c428ca493a0641cb414618d4ef46e9c0 Mon Sep 17 00:00:00 2001
From: Daniel Stenberg <daniel@haxx.se>
Date: Tue, 31 Oct 2023 16:22:07 +0100
Subject: [PATCH] urlapi: skip appending NULL pointer query

Reported-by: kirbyn17 on hackerone

Closes #12240
---
 lib/urlapi.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/urlapi.c b/lib/urlapi.c
index be27b02332..329f80393b 100644
--- a/lib/urlapi.c
+++ b/lib/urlapi.c
@@ -1902,7 +1902,7 @@ CURLUcode curl_url_set(CURLU *u, CURLUPart what,
     }
     newp = Curl_dyn_ptr(&enc);
 
-    if(appendquery) {
+    if(appendquery && newp) {
       /* Append the 'newp' string onto the old query. Add a '&' separator if
          none is present at the end of the existing query already */