Path: utzoo!attcan!uunet!snorkelwacker!bloom-beacon!EXPO.LCS.MIT.EDU!rws
From: rws@EXPO.LCS.MIT.EDU (Bob Scheifler)
Newsgroups: comp.windows.x
Subject: Re: state mask in button Press and Button Release
Message-ID: <9002201438.AA02238@expire.lcs.mit.edu>
Date: 20 Feb 90 14:38:19 GMT
References: <RAZDAN.90Feb19172730@chanakya.oakhill.uucp>
Sender: daemon@athena.mit.edu (Mr Background)
Organization: The Internet
Lines: 19


    PS: I selected for the event thru XtAddEventHandler (if that makes any
    difference)

It doesn't.

    and only one button press event was generated.

From the Xlib manual, section 8.4.1.2 (my emphasis added):

The state member is set to indicate the logical state of the pointer buttons
and modifier keys *just prior* to the event ...

Thus, when you press a button, the state won't indicate that button (although
the state will indicate that button in the button release event).

Now, if you'd already pressed the Shift key (and kept it pressed) and then
pressed the button, the state should indeed indicate Shift (and it does on
my machine).