bug#26395: 25.1; ses.el git master, inhibit-quit on some cell evaluations

[Kevin Ryde]

In debian packaged emacs 25.1 but git head ses.el, it seems cell
evaluations sometimes run with inhibit-quit.  For example, initial entry

    emacs -Q /tmp/foo.ses
    Ret                           # enter formula
    inhibit-quit Ret              # the formula
    =>
    displays t

I hoped no inhibit-quit while running formulas (and thought there wasn't
previously), as protection against slow or accidentally infinite forms.

I noticed this in my stock charting program where I communicate with a
database sub-process by accept-process-input, and that func doesn't run
under inhibit-quit.  I could with-local-quit and bail out in a sensible
way, but perhaps there's not meant to be inhibit-quit anyway.


In GNU Emacs 25.1.1 (i686-pc-linux-gnu, X toolkit, Xaw3d scroll bars)
 of 2017-01-01, modified by Debian built on x86-csail-01

Important settings:
  value of $LANG: en_AU.iso88591
  locale-coding-system: iso-latin-1-unix