anvil: Add a comment about first listen_fd being special

diff --git a/src/anvil/main.c b/src/anvil/main.c
index 0f9594159ef31bc94be6cb5585fc1592f2920e9d..a3d70570e613b932169f17d9839db3bf3677a4ea 100644 (file)
--- a/src/anvil/main.c
+++ b/src/anvil/main.c
@@ -92,6 +92,9 @@ void admin_cmd_send(const char *service, pid_t pid, const char *cmd,
 
 static void client_connected(struct master_service_connection *conn)
 {
+       /* The first listen_fd is a pipe connected directly to the master
+          process. It's not actually the first configured listener in the
+          service settings. */
        bool master = conn->listen_fd == MASTER_LISTEN_FD_FIRST;
 
        master_service_client_connection_accept(conn);