Re: Make AC_INCLUDES_DEFAULT expand its argument (shell functions 5/n)

[Akim Demaille]

| This is quite controversial.  I need to have AC_INCLUDES_DEFAULT
| expand its argument to determine whether it is empty or not, but
| m4_quote is not sufficient because it would have to add a new-line
| just like the IF-NOT-EMPTY part of the m4_ifval invocation.
|
| I am relying on m4_changecom, but I am not sure of its effects and
| would rather have someone more expert think of a better way.

These are no-no :(

| The need for this arises from this idiom in the shell functions patch,
| needed to pass to the shell function the INCLUDES argument:
| "AC_INCLUDES_DEFAULT([AS_ESCAPE([$4], ["])])"

I'm not sure shell functions are the right track for this purpose.
Everything was designed to precisely avoid dynamic changes here,
that's precisely why you meet these problems.

The goal are sane though.

I'm looking at the rest of the patches for the time being...