ui: Always remove an old VNC channel watch before adding a new one

Also set saved handle to zero when removing without adding a new watch.
Signed-off-by: NBrandon Carpenter <brandon.carpenter@cypherpath.com>
Reviewed-by: NPaolo Bonzini <pbonzini@redhat.com>
Reviewed-by: NDaniel P. Berrange <berrange@redhat.com>

ui/vnc-auth-vencrypt.c

@@ -75,6 +75,9 @@ static void vnc_tls_handshake_done(QIOTask *task,
         vnc_client_error(vs);
         error_free(err);
     } else {
+        if (vs->ioc_tag) {
+            g_source_remove(vs->ioc_tag);
+        }
         vs->ioc_tag = qio_channel_add_watch(
             vs->ioc, G_IO_IN | G_IO_OUT, vnc_client_io, vs, NULL);
         start_auth_vencrypt_subauth(vs);

ui/vnc-ws.c

@@ -37,6 +37,9 @@ static void vncws_tls_handshake_done(QIOTask *task,
         error_free(err);
     } else {
         VNC_DEBUG("TLS handshake complete, starting websocket handshake\n");
+        if (vs->ioc_tag) {
+            g_source_remove(vs->ioc_tag);
+        }
         vs->ioc_tag = qio_channel_add_watch(
             QIO_CHANNEL(vs->ioc), G_IO_IN, vncws_handshake_io, vs, NULL);
     }
@@ -97,6 +100,9 @@ static void vncws_handshake_done(QIOTask *task,
     } else {
         VNC_DEBUG("Websock handshake complete, starting VNC protocol\n");
         vnc_start_protocol(vs);
+        if (vs->ioc_tag) {
+            g_source_remove(vs->ioc_tag);
+        }
         vs->ioc_tag = qio_channel_add_watch(
             vs->ioc, G_IO_IN, vnc_client_io, vs, NULL);
     }

ui/vnc.c

@@ -1122,6 +1122,7 @@ static void vnc_disconnect_start(VncState *vs)
     vnc_set_share_mode(vs, VNC_SHARE_MODE_DISCONNECTED);
     if (vs->ioc_tag) {
         g_source_remove(vs->ioc_tag);
+        vs->ioc_tag = 0;
     }
     qio_channel_close(vs->ioc, NULL);
     vs->disconnecting = TRUE;
@@ -2934,6 +2935,9 @@ static void vnc_connect(VncDisplay *vd, QIOChannelSocket *sioc,
     VNC_DEBUG("New client on socket %p\n", vs->sioc);
     update_displaychangelistener(&vd->dcl, VNC_REFRESH_INTERVAL_BASE);
     qio_channel_set_blocking(vs->ioc, false, NULL);
+    if (vs->ioc_tag) {
+        g_source_remove(vs->ioc_tag);
+    }
     if (websocket) {
         vs->websocket = 1;
         if (vd->tlscreds) {