From 3dd1b600b8b76f480d27872f49a52b83a4960004 Mon Sep 17 00:00:00 2001
From: Lennart Poettering <lennart@poettering.net>
Date: Fri, 24 May 2019 10:44:56 +0200
Subject: [PATCH] json: permit 'null' as a way to reset tri-states to default

---
 src/shared/json.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/shared/json.c b/src/shared/json.c
index 5d3c6aad91..38b2bb14e4 100644
--- a/src/shared/json.c
+++ b/src/shared/json.c
@@ -3826,6 +3826,11 @@ int json_dispatch_tristate(const char *name, JsonVariant *variant, JsonDispatchF
         assert(variant);
         assert(b);
 
+        if (json_variant_is_null(variant)) {
+                *b = -1;
+                return 0;
+        }
+
         if (!json_variant_is_boolean(variant))
                 return json_log(variant, flags, SYNTHETIC_ERRNO(EINVAL), "JSON field '%s' is not a boolean.", strna(name));