[PATCH inputproto] specs: clarify SD keyboard focus behaviour

[Peter Hutterer]

The smart thing would be to have the SD's keyboard focus to be identical to
the MD's keyboard focus (and a BadDevice returned when trying to set an
attached SD's keyboard focus) but alas, the server never implemented this
behaviour and we've now shipped 7 versions with separate SD and MD focus. So
consider this set in stone. oops.

Signed-off-by: Peter Hutterer <peter.hutterer at who-t.net>
---
 specs/XI2proto.txt | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/specs/XI2proto.txt b/specs/XI2proto.txt
index d30fcca..79988fc 100644
--- a/specs/XI2proto.txt
+++ b/specs/XI2proto.txt
@@ -212,6 +212,8 @@ If an event is generated by an SD
 
 - if the SD is attached to a master pointer, it changes the position and/or
   button state of the master pointer.
+- if the SD has a keyboard focus other than None, the key event is sent to
+  the focus window.
 - if the SD is attached to a master keyboard, it sends events to this
   keyboard's focus window (if applicable) and/or changes the modifier state of
   this keyboard.
@@ -220,6 +222,13 @@ If an event is generated by an SD
   Both the sprite and the focus must be managed explicitly by the client
   program.
 
+Note: the keyboard focus of an attached slave device is independent to that
+of the master device. Two keyboard events are generated, once with deviceid
+and sourceid set to the slave device. This keyboard event is sent to the
+slave device's focus window. The second event has a deviceid of the master
+and a sourceid of the slave device. This second event is delivered to the
+master keyboard's focus window.
+
 [[hierarchy-dcce]]
 Event processing for attached slave devices
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-- 
1.8.2.1