From c59555a86d3fcd2b8d644885134e19fe864251e5 Mon Sep 17 00:00:00 2001
From: Daan De Meyer <daan.j.demeyer@gmail.com>
Date: Fri, 11 Nov 2022 11:26:54 +0100
Subject: [PATCH] strv: Make sure strv_make_nulstr() always returns a valid
 nulstr

strv_make_nulstr() is documented to always return a valid nulstr,
but if the input is `NULL` we return a string terminated with only
a single NUL terminator, so let's fix that and always terminate the
resulting string with two NUL bytes.

(cherry picked from commit 5ea173a91b2093664a9ebb9add678edd6f5d1efd)

Related: #2138081
---
 src/basic/strv.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/src/basic/strv.c b/src/basic/strv.c
index eea34ca68d..24fc56a1a5 100644
--- a/src/basic/strv.c
+++ b/src/basic/strv.c
@@ -721,7 +721,7 @@ int strv_make_nulstr(char * const *l, char **ret, size_t *ret_size) {
         }
 
         if (!m) {
-                m = new0(char, 1);
+                m = new0(char, 2);
                 if (!m)
                         return -ENOMEM;
                 n = 1;
@@ -730,11 +730,9 @@ int strv_make_nulstr(char * const *l, char **ret, size_t *ret_size) {
                 m[n] = '\0';
 
         assert(n > 0);
-        *ret = m;
+        *ret = TAKE_PTR(m);
         *ret_size = n - 1;
 
-        m = NULL;
-
         return 0;
 }