no op when message is NULL
@@ -68,6 +68,8 @@ sixel_helper_set_additional_message(
{
size_t len;
+ if (message == 0)
+ return;
len = strlen(message);
memcpy(g_buffer, message, len < sizeof(g_buffer) ? len: sizeof(g_buffer) - 1);
g_buffer[sizeof(g_buffer) - 1] = 0;
