andrew dasys <adasys@objectivity.ca> wrote:

> Nick,
> thank you for looking at this.
> 
> I am running Emacs 21.4.1 Nothing bleeding edge here.
> 
> The help for split-string looks reasonable  (compiled Lisp comes from "subr" ....) (complete output attached)
> 
...

> split-string is a compiled Lisp function in `subr'.
> (split-string STRING &optional SEPARATORS)
> 
> Splits STRING into substrings where there are matches for SEPARATORS.
> Each match for SEPARATORS is a splitting point.
> The substrings between the splitting points are made into a list
> which is returned.
> If SEPARATORS is absent, it defaults to "[ \f\t\n\r\v]+".
> 
> If there is match for SEPARATORS at the beginning of STRING, we do not
> include a null substring for that.  Likewise, if there is a match
> at the end of STRING, we don't include a null substring for that.
> 
> Modifies the match data; use `save-match-data' if necessary.

I think that explains it: split-string takes one mandatory and two
optional arguments (separator regexp and an omit-nulls boolean) in
emacs-22/23; but only *one* optional argument in emacs-21 (the separator
arg). The org latex-exporting code calls it with two optional arguments
and that makes the emacs-21 implementation of split-string blow up.

I just did an experiment: in my emacs-23, I called split-string
with one mandatory and *three* more arguments:

(split-string "foo
bar
baz" "\n" t t)

and I got

Debugger entered--Lisp error: (wrong-number-of-arguments #[(string &optional separators omit-nulls) "ƒ