From 257c8e8d3b7103973dfdc2665d210c63496be457 Mon Sep 17 00:00:00 2001
From: Rui Matos <tiagomatos@gmail.com>
Date: Tue, 6 Oct 2015 21:16:18 +0200
Subject: [PATCH] monitor-manager-xrandr: Work around spurious hotplugs on Xvnc

Xvnc turns its outputs off/on on every mode set which makes us believe
there was an hotplug when there actually wasn't. Work around this by
requiring new randr configuration timestamps to be ahead of the last
set timestamp by at least 100 ms for us to consider them an actual
hotplug.
---
 src/backends/x11/meta-monitor-manager-xrandr.c | 19 ++++++++++++++++++-
 1 file changed, 18 insertions(+), 1 deletion(-)

diff --git a/src/backends/x11/meta-monitor-manager-xrandr.c b/src/backends/x11/meta-monitor-manager-xrandr.c
index b82120af9..4a27b3a14 100644
--- a/src/backends/x11/meta-monitor-manager-xrandr.c
+++ b/src/backends/x11/meta-monitor-manager-xrandr.c
@@ -1484,12 +1484,25 @@ meta_monitor_manager_xrandr_class_init (MetaMonitorManagerXrandrClass *klass)
 #endif
 }
 
+static gboolean
+is_xvnc (MetaMonitorManager *manager)
+{
+  unsigned int i;
+
+  for (i = 0; i < manager->n_outputs; ++i)
+    if (g_str_has_prefix (manager->outputs[i].name, "VNC-"))
+      return TRUE;
+
+  return FALSE;
+}
+
 gboolean
 meta_monitor_manager_xrandr_handle_xevent (MetaMonitorManagerXrandr *manager_xrandr,
 					   XEvent                   *event)
 {
   MetaMonitorManager *manager = META_MONITOR_MANAGER (manager_xrandr);
   gboolean hotplug;
+  unsigned int timestamp;
 
   if ((event->type - manager_xrandr->rr_event_base) != RRScreenChangeNotify)
     return FALSE;
@@ -1498,7 +1511,11 @@ meta_monitor_manager_xrandr_handle_xevent (MetaMonitorManagerXrandr *manager_xra
 
   meta_monitor_manager_read_current_config (manager);
 
-  hotplug = manager_xrandr->resources->timestamp < manager_xrandr->resources->configTimestamp;
+  timestamp = manager_xrandr->resources->timestamp;
+  if (is_xvnc (manager))
+    timestamp += 100;
+
+  hotplug = timestamp < manager_xrandr->resources->configTimestamp;
   if (hotplug)
     {
       /* This is a hotplug event, so go ahead and build a new configuration. */
-- 
2.12.0