From 7666542ab6aab8ac191d5bda465e20e7948992ef Mon Sep 17 00:00:00 2001
From: Christian Grothoff <christian@grothoff.org>
Date: Thu, 23 Apr 2020 15:22:41 +0200
Subject: [PATCH] fix #6219

---
 src/util/url.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/util/url.c b/src/util/url.c
index c64dfbc4f..934bb058a 100644
--- a/src/util/url.c
+++ b/src/util/url.c
@@ -148,6 +148,9 @@ calculate_argument_length (va_list args)
                     char *);
     if (NULL == value)
       continue;
+    GNUNET_assert ( (len <= len + urlencode_len (value)) &&
+                    (len <= len + urlencode_len (value) + strlen (key)) &&
+                    (len < len + urlencode_len (value) + strlen (key) + 2) );
     len += urlencode_len (value) + strlen (key) + 2;
   }
   va_end (ap);