Xi: add "deletable" flag to properties, add DeleteProperty handler.

A property can only be deleted if any of the following is true:
- if a property is deletable and all handlers return Success.
- if a property is non-deleteable and the all handlers return Success AND the
  delete request does not come from a client (i.e. driver or the server).

A client can never delete a non-deletable property.

1 files changed, 2 insertions, 1 deletions

diff --git a/dix/devices.c b/dix/devices.c
index fb634730f..e6f21c924 100644
--- a/dix/devices.c
+++ b/dix/devices.c
@@ -223,7 +223,8 @@ AddInputDevice(ClientPtr client, DeviceProc deviceProc, Bool autoStart)
     XIChangeDeviceProperty(dev, XIGetKnownProperty(XI_PROP_ENABLED),
                            XA_INTEGER, 8, PropModeReplace, 1, &dev->enabled,
                            FALSE);
-    XIRegisterPropertyHandler(dev, DeviceSetProperty, NULL);
+    XISetDevicePropertyDeletable(dev, XIGetKnownProperty(XI_PROP_ENABLED), FALSE);
+    XIRegisterPropertyHandler(dev, DeviceSetProperty, NULL, NULL);
 
     return dev;
 }