1 files changed, 16 insertions, 0 deletions
diff --git a/chardev/char-socket.c b/chardev/char-socket.c
index 8a0406cc1e..2c4dffc0e6 100644
--- a/chardev/char-socket.c
+++ b/chardev/char-socket.c
@@ -601,6 +601,22 @@ static void update_ioc_handlers(SocketChardev *s)
 
     remove_hup_source(s);
     s->hup_source = qio_channel_create_watch(s->ioc, G_IO_HUP);
+    /*
+     * poll() is liable to return POLLHUP even when there is
+     * still incoming data available to read on the FD. If
+     * we have the hup_source at the same priority as the
+     * main io_add_watch_poll GSource, then we might end up
+     * processing the POLLHUP event first, closing the FD,
+     * and as a result silently discard data we should have
+     * read.
+     *
+     * By setting the hup_source to G_PRIORITY_DEFAULT + 1,
+     * we ensure that io_add_watch_poll GSource will always
+     * be dispatched first, thus guaranteeing we will be
+     * able to process all incoming data before closing the
+     * FD
+     */
+    g_source_set_priority(s->hup_source, G_PRIORITY_DEFAULT + 1);
     g_source_set_callback(s->hup_source, (GSourceFunc)tcp_chr_hup,
                           chr, NULL);
     g_source_attach(s->hup_source, chr->gcontext);