[mutter] monitor-manager-kms: Cope with non-existent connectors and encoders

[Rui Matos <rtcm src gnome org>]

commit db9645fcb3ca37d1598bffe9276692ac46906755
Author: Rui Matos <tiagomatos gmail com>
Date:   Mon Mar 2 17:38:41 2015 +0100

    monitor-manager-kms: Cope with non-existent connectors and encoders
    
    DRM objects like connectors and encoders might change at any time, in
    particular they might become invalid between drmModeGetResources() and
    getting the actual objects in which case they'll be NULL. Be defensive
    against that.
    
    Note that, if this happens, we should get another udev event soon
    which will cause us to update our state.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=745476

 src/backends/native/meta-monitor-manager-kms.c |    9 ++++++---
 1 files changed, 6 insertions(+), 3 deletions(-)
---
diff --git a/src/backends/native/meta-monitor-manager-kms.c b/src/backends/native/meta-monitor-manager-kms.c
index eeb5877..836df3b 100644
--- a/src/backends/native/meta-monitor-manager-kms.c
+++ b/src/backends/native/meta-monitor-manager-kms.c
@@ -366,7 +366,7 @@ meta_monitor_manager_kms_read_current (MetaMonitorManager *manager)
       connector = drmModeGetConnector (manager_kms->fd, resources->connectors[i]);
       manager_kms->connectors[i] = connector;
 
-      if (connector->connection == DRM_MODE_CONNECTED)
+      if (connector && connector->connection == DRM_MODE_CONNECTED)
         {
           /* Collect all modes for this connector */
           for (j = 0; j < (unsigned)connector->count_modes; j++)
@@ -460,7 +460,7 @@ meta_monitor_manager_kms_read_current (MetaMonitorManager *manager)
       connector = manager_kms->connectors[i];
       meta_output = &manager->outputs[n_actual_outputs];
 
-      if (connector->connection == DRM_MODE_CONNECTED)
+      if (connector && connector->connection == DRM_MODE_CONNECTED)
        {
           meta_output->driver_private = output_kms = g_slice_new0 (MetaOutputKms);
           meta_output->driver_notify = (GDestroyNotify)meta_output_destroy_notify;
@@ -509,6 +509,8 @@ meta_monitor_manager_kms_read_current (MetaMonitorManager *manager)
          for (j = 0; j < output_kms->n_encoders; j++)
            {
               output_kms->encoders[j] = drmModeGetEncoder (manager_kms->fd, connector->encoders[j]);
+              if (!output_kms->encoders[j])
+                continue;
 
               /* We only list CRTCs as supported if they are supported by all encoders
                  for this connectors.
@@ -616,7 +618,8 @@ meta_monitor_manager_kms_read_current (MetaMonitorManager *manager)
        {
          for (k = 0; k < (unsigned)resources->count_encoders; k++)
            {
-             if (output_kms->encoders[j]->encoder_id == encoders[k]->encoder_id)
+              if (output_kms->encoders[j] && encoders[k] &&
+                  output_kms->encoders[j]->encoder_id == encoders[k]->encoder_id)
                {
                   output_kms->encoder_mask |= (1 << k);
                  break;