Re: AC_PREFIX_PATH, AS_BASENAME fixes and a new test!

[Tim Van Holder]

> The AS_BASENAME fix doesn't seem complete to me.
> AS_BASENAME should look like AS_DIRNAME, e.g. something like this:
> 
>       # AS_BASENAME(PATHNAME)
>       # --------------------
>       # Simulate running `basename(1)' on PATHNAME, not all 
> systems have it.
>       # Also see the comments for AS_DIRNAME.
>       m4_defun([AS_BASENAME_EXPR],
>       [m4_require([_AS_EXPR_PREPARE])dnl
>       $as_expr X[]$1 : '.*/\([^/][^/]*\)/*$' \| \
>                X[]$1 : '\([^/][^/]*\)/*$' \|
>                X[]$1 : 'X\(//\)$' \| \
>                X[]$1 : 'X\(/\)/*$' \| \
>                .     : '\(.\)'])
> 
>       m4_defun([AS_BASENAME_SED],
>       [echo X[]$1 | 
>           sed ['???']])
> 
>       m4_defun([AS_BASENAME],
>       [AS_BASENAME_EXPR([$1]) 2>/dev/null ||
>       AS_BASENAME_SED([$1])])
> 
> except you need to fill in the '???'.

Plus you'd want to use [\\/] matchers for the directory separator in
order to support DOS paths (something currently lacking in AS_DIRNAME
too, I believe).