Comment 2 for bug 1274456

The bug seems to be in client/hostinfo_unix.cpp.
According to documentation, right after XOpenDisplay call, there should be XScreenSaverQueryExtension call.
See http://linux.die.net/man/3/xscreensaverqueryextension .

So this:

        disp = XOpenDisplay(NULL);
         // XOpenDisplay may return NULL if there is no running X
         // or DISPLAY points to wrong/invalid display
         if(disp != NULL) {
             xssInfo = XScreenSaverAllocInfo();
         }

Should continue like this:

  if (XScreenSaverQueryExtension(disp, &event_base_return, &error_base_return) == false ) //Undeclared variables are integers.
            //Error handling here!

I would have investigate and test this by myself, but compiling documentation of BOINC is incorrect and workarounds presented on forums didn't help. I don't have the patience.