Re: AC_DEFUN_ONCE semantics

[Ralf Wildenhues]

* Eric Blake wrote on Tue, Jan 27, 2009 at 02:53:12AM CET:
> On the other hand, the manual already said that inside the body of an
> AC_DEFUN'd macro (such as AS_IF), you should use AC_REQUIRE([foo]), never
> direct foo.  So if you were already obeying the manual, you should never
> run into this particular change in semantics.

How long has this recommendation existed, and more importantly, how much
does it match existing practice outside of any of the dozen very well
updated GNU packages?

Cheers,
Ralf