Crash on make-frame-on-display with SSH display

[Martin Schwenke]

In GNU Emacs 20.7.2 (i386-debian-linux-gnu, X toolkit)
 of Wed Jun 21 2000 on raven
configured using `configure  i386-debian-linux-gnu --prefix=/usr 
--sharedstatedir=/var/lib --libexecdir=/usr/lib --localstatedir=/var/lib 
--infodir=/usr/share/info --with-pop=yes --with-x=yes --with-x-toolkit=yes'

Please describe exactly what actions triggered the bug
and the precise symptoms of the bug:

1. Start Emacs under X (with "-q" if you like, shouldn't matter).

2. From an xterm:

     ssh localhost

   and then from the SSH session:

     echo $DISPLAY

3. In Emacs, evaluate:

     (make-frame-on-display "DISPLAY-FROM-ABOVE")

   Emacs exits.

   This can also be triggered by calling

     (x-open-connection "DISPLAY-FROM-ABOVE")

You wouldn't expect this to necessarily work, since SSH puts the magic
cookie for the display in its own file somewhere under /tmp and sets
$XAUTHORITY accordingly (I'm using the Debian OpenSSH package, version
1.2.3-9).  Emacs doesn't know where to find the xauth file, so it
should fail to open the frame.  However, it should not exit.

This can be worked around by doing the following in the SSH session:

    xauth extract - $DISPLAY | xauth -f $HOME/.Xauthority merge -

This means that Emacs can get at the relevant cookie via the standard
.Xauthority file...

peace & happiness,
martin

-- 
Martin Schwenke,  Technical Support Engineer,  Linuxcare, Inc.
+61 2 6262 8990
martins@linuxcare.com,  http://linuxcare.com.au/
Linuxcare.  Support for the revolution.