How can I configure X not to shutdown when I accidentally press
control-alt-backspace?  This happens a lot, believe it or not, while
I'm using emacs.  If X were to pop up a confirmation dialog, that
would be even better.

Yes, you just need to add a DONTZAP variable to your XF86Config file.
Here's what one example page had listed:

"
Section "ServerFlags"
    # DontZap will stop control-alt-backspace from killing the X
server
    # I never really liked the thought that anybody could dump out of
X
    # even if it was locked (with xlock, or something similar).
    DontZap
EndSection
"


If you're unsure about how to do this, take a look at the
documentation for your specific X version, but it should be in the
XF86Config file.


Additional Links:

Sample XF86Config file
http://www.dotfiles.com/files/13/179_XF86Config

Discussion on answer:
http://www.xfree86.org/pipermail/xpert/2000-September/001863.html

Another suggestion with same answer:
http://www.xfree86.org/pipermail/xpert/2000-September/001865.html


Search Strategy:

"disable control alt backspace" on google:
://www.google.com/search?q=%22disable+control+alt+backspace%22

dontzap "control alt backspace" on google:
://www.google.com/search?q=dontzap+%22control+alt+backspace%22


Thank you for the opportunity to answer your question, if you require
more information, please clarify the question, or if you find this
answer satisfactory, please feel free to rate it. Thank you!

skermit-ga