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From: porsche@hpcvlx.cv.hp.com. (John Milton)
Newsgroups: comp.sys.hp
Subject: Re: Xterm HP-UX 7.03 and me
Message-ID: <101950235@hpcvlx.cv.hp.com.>
Date: 20 Jun 91 22:29:21 GMT
References: <1991Jun13.111656.19463@doug.cae.wisc.edu>
Organization: Hewlett-Packard Co., Corvallis, OR, USA
Lines: 27

This is the result of a change to the 7.0 version of getpgrp2 to make it POSIX
compliant.  (Evidentally, MIT ran into this problem because it has been fixed
in the R4 version of xterm.)  In the version of xterm supplied with 7.0x, 
selecting the 'Send INT signal' item from the menu causes the following line
to be executed:

    killpg(getpgrp(screen->pid), SIGINT);
    
Which, after substituting for macro definitions, becomes:

    kill(-(getpgrp2(screen->pid)), SIGINT);

In HP-UX 7.0 (and presumably any POSIX compliant OS) getpgrp2 fails if the
current process (xterm) and the specified process (the shell) are not in the
same session (which they aren't).  Thus, when getpgrp2 fails, SIGINT is sent
to init (-(-1)=1), forcing init to run level 0.  The Release 4 version of
xterm is supplied with HP-UX 8.0 and the code has been changed, sending the
signal to the process id of the shell process instead of the shell's process
group (it doesn't call getpgrp2).

Until you upgrade to HP-UX 8.0 don't select the 'Send INT signal' item in the
'Main Options' menu.  (Actually, you probably shouldn't select any of the send
signal options because, for the reasons outlined above, the signal is sent to
init rather than the shell's process group.)

John "porsche is a two syllable word" Milton
porsche@hp-pcd