From 073a328a3031faa82d388805c0a6890d4de001df 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 4c1b16c..190aeac 100644
--- a/src/backends/x11/meta-monitor-manager-xrandr.c
+++ b/src/backends/x11/meta-monitor-manager-xrandr.c
@@ -1064,6 +1064,18 @@ meta_monitor_manager_xrandr_class_init (MetaMonitorManagerXrandrClass *klass)
   manager_class->set_crtc_gamma = meta_monitor_manager_xrandr_set_crtc_gamma;
 }
 
+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)
@@ -1075,6 +1087,7 @@ meta_monitor_manager_xrandr_handle_xevent (MetaMonitorManagerXrandr *manager_xra
   unsigned int n_old_outputs, n_old_modes;
   gboolean new_config;
   gboolean applied_config = FALSE;
+  unsigned int timestamp;
 
   if ((event->type - manager_xrandr->rr_event_base) != RRScreenChangeNotify)
     return FALSE;
@@ -1091,7 +1104,11 @@ meta_monitor_manager_xrandr_handle_xevent (MetaMonitorManagerXrandr *manager_xra
   manager->serial++;
   meta_monitor_manager_xrandr_read_current (manager);
 
-  new_config = manager_xrandr->resources->timestamp >= manager_xrandr->resources->configTimestamp;
+  timestamp = manager_xrandr->resources->timestamp;
+  if (is_xvnc (manager))
+    timestamp += 100;
+
+  new_config = timestamp >= manager_xrandr->resources->configTimestamp;
 
   /* If this is the X server telling us we set a new configuration,
    * we can simply short-cut to rebuilding our logical configuration.
-- 
2.4.3