From 4ad8fd80355189ecbde6c38961335ae4be4db8b3 Mon Sep 17 00:00:00 2001
From: rpm-build <rpm-build>
Date: Tue, 11 Sep 2018 10:19:44 -0400
Subject: [PATCH] monitor-manager: only reuse initial-config if monitor
 topology matches startup

Right now we try to apply the current monitor config when a new
monitor is attached.  The current config obviously doesn't include the
new monitor, so the new monitor isn't lit up.

The only reason we apply the current config at all is to handle the
startup case:  We want to reuse the config set in Xorg when first
logging in.

This commit changes the code to look at the *initial config* instead
of the current config, and only if the new monitor topology matches
the start up topology.
---
 src/backends/meta-monitor-config-manager.c | 20 +++++++++++++++-----
 src/backends/meta-monitor-config-manager.h |  2 +-
 src/backends/meta-monitor-manager.c        | 16 +++++++++++++++-
 3 files changed, 31 insertions(+), 7 deletions(-)

diff --git a/src/backends/meta-monitor-config-manager.c b/src/backends/meta-monitor-config-manager.c
index d64ca1f79..c09edbe00 100644
--- a/src/backends/meta-monitor-config-manager.c
+++ b/src/backends/meta-monitor-config-manager.c
@@ -42,6 +42,7 @@ struct _MetaMonitorConfigManager
   MetaMonitorConfigStore *config_store;
 
   MetaMonitorsConfig *current_config;
+  MetaMonitorsConfig *initial_config;
   GQueue config_history;
 };
 
@@ -663,9 +664,10 @@ create_logical_monitor_config_from_output (MetaMonitorManager           *monitor
 }
 
 MetaMonitorsConfig *
-meta_monitor_config_manager_create_current (MetaMonitorConfigManager *config_manager)
+meta_monitor_config_manager_create_initial (MetaMonitorConfigManager *config_manager)
 {
   MetaMonitorManager *monitor_manager = config_manager->monitor_manager;
+  MetaMonitorsConfig *initial_config;
   GList *logical_monitor_configs;
   MetaMonitor *primary_monitor;
   MetaLogicalMonitorLayoutMode layout_mode;
@@ -673,6 +675,9 @@ meta_monitor_config_manager_create_current (MetaMonitorConfigManager *config_man
   GList *monitors;
   GList *l;
 
+  if (config_manager->initial_config != NULL)
+    return g_object_ref (config_manager->initial_config);
+
   if (meta_monitor_config_store_get_config_count (config_manager->config_store) > 0)
     return NULL;
 
@@ -714,10 +719,14 @@ meta_monitor_config_manager_create_current (MetaMonitorConfigManager *config_man
                                                logical_monitor_config);
     }
 
-  return meta_monitors_config_new (monitor_manager,
-                                   logical_monitor_configs,
-                                   layout_mode,
-                                   META_MONITORS_CONFIG_FLAG_NONE);
+  initial_config = meta_monitors_config_new (monitor_manager,
+                                             logical_monitor_configs,
+                                             layout_mode,
+                                             META_MONITORS_CONFIG_FLAG_NONE);
+
+  config_manager->initial_config = g_object_ref (initial_config);
+
+  return initial_config;
 }
 
 MetaMonitorsConfig *
@@ -1256,6 +1265,7 @@ meta_monitor_config_manager_dispose (GObject *object)
     META_MONITOR_CONFIG_MANAGER (object);
 
   g_clear_object (&config_manager->current_config);
+  g_clear_object (&config_manager->initial_config);
   meta_monitor_config_manager_clear_history (config_manager);
 
   G_OBJECT_CLASS (meta_monitor_config_manager_parent_class)->dispose (object);
diff --git a/src/backends/meta-monitor-config-manager.h b/src/backends/meta-monitor-config-manager.h
index 364a2b36b..409611bb0 100644
--- a/src/backends/meta-monitor-config-manager.h
+++ b/src/backends/meta-monitor-config-manager.h
@@ -95,7 +95,7 @@ META_EXPORT_TEST
 MetaMonitorsConfig * meta_monitor_config_manager_get_stored (MetaMonitorConfigManager *config_manager);
 
 META_EXPORT_TEST
-MetaMonitorsConfig * meta_monitor_config_manager_create_current (MetaMonitorConfigManager *config_manager);
+MetaMonitorsConfig * meta_monitor_config_manager_create_initial (MetaMonitorConfigManager *config_manager);
 META_EXPORT_TEST
 MetaMonitorsConfig * meta_monitor_config_manager_create_linear (MetaMonitorConfigManager *config_manager);
 
diff --git a/src/backends/meta-monitor-manager.c b/src/backends/meta-monitor-manager.c
index 05b27c6be..bb4b44188 100644
--- a/src/backends/meta-monitor-manager.c
+++ b/src/backends/meta-monitor-manager.c
@@ -534,9 +534,11 @@ should_use_stored_config (MetaMonitorManager *manager)
 MetaMonitorsConfig *
 meta_monitor_manager_ensure_configured (MetaMonitorManager *manager)
 {
+  g_autoptr (MetaMonitorsConfig) initial_config = NULL;
   MetaMonitorsConfig *config = NULL;
   GError *error = NULL;
   gboolean use_stored_config;
+  MetaMonitorsConfigKey *current_state_key;
   MetaMonitorsConfigMethod method;
   MetaMonitorsConfigMethod fallback_method =
     META_MONITORS_CONFIG_METHOD_TEMPORARY;
@@ -547,6 +549,18 @@ meta_monitor_manager_ensure_configured (MetaMonitorManager *manager)
   else
     method = META_MONITORS_CONFIG_METHOD_TEMPORARY;
 
+  initial_config = meta_monitor_config_manager_create_initial (manager->config_manager);
+
+  if (initial_config)
+    {
+      current_state_key = meta_create_monitors_config_key_for_current_state (manager);
+
+      /* don't ever reuse initial configuration, if the monitor topology changed
+       */
+      if (current_state_key && !meta_monitors_config_key_equal (current_state_key, initial_config->key))
+        g_clear_object (&initial_config);
+    }
+
   if (use_stored_config)
     {
       config = meta_monitor_config_manager_get_stored (manager->config_manager);
@@ -614,7 +628,7 @@ meta_monitor_manager_ensure_configured (MetaMonitorManager *manager)
       g_clear_object (&config);
     }
 
-  config = meta_monitor_config_manager_create_current (manager->config_manager);
+  config = g_steal_pointer (&initial_config);
   if (config)
     {
       if (!meta_monitor_manager_apply_monitors_config (manager,
-- 
2.21.0