Re: address@hidden: 21.1 on Solaris 2.5.1 (sparc), on terminal, core dump]

[Richard Stallman]

    But that is only a partial fix.  The problem is not limited to Solaris
    2.5 and later: it will also occur on earlier Solaris versions, and I
    think it'll occur on other hosts as well.  The more general problem is
    that Emacs sometimes uses vfork without defining HAVE_VFORK.

That itself seems like an anomaly.  How does it come about that Emacs
uses vfork when HAVE_VFORK is not defined?  Does Emacs use vfork directly,
or does it call library subroutines that use it?

I wonder why HAVE_VFORK wasn't defined on older Solaris versions.
They have all had vfork.  Was it broken?

    One way to fix the more general problem would be to use the
    AC_FUNC_FORK of Autoconf 2.51 and later.  It defines a macro
    HAVE_WORKING_VFORK that Emacs could use instead of HAVE_VFORK.

Does HAVE_WORKING_VFORK operate by executing a test program?
It is desirable to avoid that kind of Autoconf test, because it does
not work in cross-compilation.