Re: behaviour of PATH argument in AC_PATH_PROG

[Lars Hecking]

> I  was beating myself over the head wondering why my AC_PATH_PROG 
> invocation couldn't find iptables.  I'm using autoconf 2.57 on red hat 9.
> 
> Here's what I had :
> 
> AC_PATH_PROG(IPTABLES, iptables, no, $PATH:/usr/sbin:/usr/bin:/sbin)
> 
> Here's what the info page gives as an example :
> 
>      AC_PATH_PROG([INETD], [inetd], [/usr/libexec/inetd],
>                   [$PATH:/usr/libexec:/usr/sbin:/usr/etc:etc])
> 
> I dug into the resulting configure code and it seems that that code 
> interpolates the macro so that is uses a for loop to go over the 
> PATH argument.
> 
> So, taking a cue from that, I replaced the colons with spaces and now it
> works.
 
 That can't be right, because configure sets IFS=$PATH_SEPARATOR before
 entering the for loop. There was a bug in this area in autoconf 2.5x up
 to 2.53, but it has been fixed since.

 Are you sure this is really autoconf 2.57? Does the generated configure
 script contain the

as_dummy="$PATH:/usr/libexec:/usr/sbin:/usr/etc:etc"

 line right before the for loop?

> I seem to vaguely recall that using colons used to work on older 
> autoconfs.  Is this an actual bug ? A feature regression ? Should the info 
> page be updated for it ?
> 
> If anybody can tell me some more I'm willing to provide a patch to fix 
> whatever's necessary for this.