Symptoms
You cannot type in an ICA Full Screen session if you press the Windows key + U.
When the keyboard hook procedure receives KEYDOWN events of Windows key and U or L key, it synthesizes four keystrokes (KEYDOWN of Windows key, KEYDOWN of U or L key, KEYUP of U or L key and KEYUP of Windows key) and shifts to Transient Local Mode that does not make the window procedure send the server any key entered.
After that, if the window procedure of ICA receives all the messages of the keystrokes synthesized, it returns to Remote Mode that makes the window procedure send the Server every key entered.
However, the system does not send KEYDOWN message of U or L key to the window and after the window procedure receives KEYUP messages of U or L key and Windows key, in addition, it receives KEYUP messages of U or L key and Windows key suspended by synthesizing the keystrokes. In short, it receives KEYUP messages of U or L key and Windows key two times.
As a result, the transition of state of the window procedure fails and the state never returns to Remote Mode.
Usually Lock Display or Open Utility Manager causes a focus event. The state of the window procedure is initialized at that time. But if Lock Display or Open Utility Manager has been disabled, this problem occurs.
Resolution
CTX121195 – Citrix Online Plug-in 11.2 Fixed Issues – English
Users cannot type in a full-screen session after pressing Windows logo key + U.
[#190268]
Workarounds
Modify the Windows key state transition table in consideration that the window procedure receives KEYUP messages of U or L key and Windows key without KEYDOWN message of U or L.
– Or –
Make the keyboard hook procedure synthesize only two keystrokes (KEYDOWN of Windows key and U or L key) for the Windows key + U or L because it receives KEYUP events soon.
