From e7fa743d920c9c201bcf1e42e2c0058249a5c1e5 Mon Sep 17 00:00:00 2001
From: "Daniel P. Berrange" <berrange@redhat.com>
Date: Thu, 8 Feb 2018 17:50:27 +0100
Subject: [PATCH 13/27] vnc: only alloc server surface with clients connected

RH-Author: Daniel P. Berrange <berrange@redhat.com>
Message-id: <20180208175041.5634-14-berrange@redhat.com>
Patchwork-id: 78956
O-Subject: [RHEL-7.5 qemu-kvm PATCH v1 13/27] vnc: only alloc server surface with clients connected
Bugzilla: 1527405
RH-Acked-by: Laszlo Ersek <lersek@redhat.com>
RH-Acked-by: Gerd Hoffmann <kraxel@redhat.com>
RH-Acked-by: Miroslav Rezanina <mrezanin@redhat.com>

From: Gerd Hoffmann <kraxel@redhat.com>

RHEL-7 note: (a) the "graphic_hw_update(NULL)" call is different in the
upstream context due to commit 1d0d59fe2919 ("vnc: allow binding servers
to qemu consoles", 2015-01-22). That commit talks about "multiseat" and
is part of v2.3.0, so out of scope for this backport. (b) The
QTAILQ_INSERT_HEAD() macro invocation is QTAILQ_INSERT_TAIL() in the
upstream context, due to commit e5f34cdd2da5 ("vnc: track &
limit connections", 2015-01-22), part of v2.3.0. That commit is also
irrelevant for this backport.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Peter Lieven <pl@kamp.de>
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 1446203414-4013-15-git-send-email-kraxel@redhat.com
(cherry picked from commit c7628bff4138ce906a3620d12e0820c1cf6c140d)

 Conflicts:
	ui/vnc.c - context differences

Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
---
 ui/vnc.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/ui/vnc.c b/ui/vnc.c
index df081a5..dc09089 100644
--- a/ui/vnc.c
+++ b/ui/vnc.c
@@ -620,6 +620,10 @@ static void vnc_update_server_surface(VncDisplay *vd)
     qemu_pixman_image_unref(vd->server);
     vd->server = NULL;
 
+    if (QTAILQ_EMPTY(&vd->clients)) {
+        return;
+    }
+
     vd->server = pixman_image_create_bits(VNC_SERVER_FB_FORMAT,
                                           vnc_width(vd),
                                           vnc_height(vd),
@@ -1019,6 +1023,10 @@ void vnc_disconnect_finish(VncState *vs)
     if (vs->initialized) {
         QTAILQ_REMOVE(&vs->vd->clients, vs, next);
         qemu_remove_mouse_mode_change_notifier(&vs->mouse_mode_notifier);
+        if (QTAILQ_EMPTY(&vs->vd->clients)) {
+            /* last client gone */
+            vnc_update_server_surface(vs->vd);
+        }
     }
 
     if (vs->vd->lock_key_sync)
@@ -2819,6 +2827,7 @@ void vnc_init_state(VncState *vs)
 {
     vs->initialized = true;
     VncDisplay *vd = vs->vd;
+    bool first_client = QTAILQ_EMPTY(&vd->clients);
 
     vs->last_x = -1;
     vs->last_y = -1;
@@ -2832,6 +2841,9 @@ void vnc_init_state(VncState *vs)
     vs->bh = qemu_bh_new(vnc_jobs_bh, vs);
 
     QTAILQ_INSERT_HEAD(&vd->clients, vs, next);
+    if (first_client) {
+        vnc_update_server_surface(vd);
+    }
 
     graphic_hw_update(NULL);
 
-- 
1.8.3.1