json: Assert json_parser_parse() consumes all tokens on success

Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Message-Id: <20180823164025.12553-47-armbru@redhat.com>

qobject/json-parser.c

@@ -544,6 +544,7 @@ QObject *json_parser_parse(GQueue *tokens, va_list *ap, Error **errp)
     QObject *result;
 
     result = parse_value(&ctxt, ap);
+    assert(ctxt.err || g_queue_is_empty(ctxt.buf));
 
     error_propagate(errp, ctxt.err);