Fix crash on Windows when a socket is available for both write and read.

[tinc] / src / event.c

diff --git a/src/event.c b/src/event.c
index 59b96e3..858e1d9 100644 (file)
--- a/src/event.c
+++ b/src/event.c
@@ -357,10 +357,13 @@ bool event_loop(void) {
                        WSANETWORKEVENTS network_events;
                        if (WSAEnumNetworkEvents(io->fd, io->event, &network_events) != 0)
                                return false;
-                       if (network_events.lNetworkEvents & WRITE_EVENTS)
-                               io->cb(io->data, IO_WRITE);
                        if (network_events.lNetworkEvents & READ_EVENTS)
                                io->cb(io->data, IO_READ);
+                       /*
+                           The fd might be available for write too. However, if we already fired the read callback, that
+                           callback might have deleted the io (e.g. through terminate_connection()), so we can't fire the
+                           write callback here. Instead, we loop back and let the writable io loop above handle it.
+                        */
                }
        }
 #endif