Symbols in executable available to dynamic stuff

[Geoff Wing <gcw@xxxxxxxxx>]

Heyla,
can I cause some more trouble yet? :-)

Way, way back in Zefram's patch 3038 came aczsh.m4 and this gem:
zsh_SYS_DYNAMIC_EXECSYMS:
    Check whether symbols in the executable are available to dynamically
    loaded libraries.
(And BTW, the description's wrong: it checks dynamically loaded objects,
which are not necessarily libraries)

If yes, then we don't build a dynamic zsh.  What's the danger here?  If
you control your executable, library and $MODULEPATH then why does it
matter if objects you load can run subroutines from outside their object
space?  Or is it more specific than that?  Obviously, routines in
dynamically loaded modules (eg. genprompts() in zle module) need to be able
to run routines in other modules or libraries (eg. countprompt() in zsh
library) so there is some big thing here I'm missing perhaps?

Anyone care to enlighten me, please?
-- 
Geoff Wing   <gcw@xxxxxxxxx>            Mobile : 0412 162 441
Work URL: http://www.primenet.com.au/   Ego URL: http://pobox.com/~gcw/