Re: Possible bug in symbolic link determination

[Ralf Wildenhues]

Hello Mikael,

Thanks for the report.

* Mikael Andersson wrote on Wed, Feb 14, 2007 at 06:55:04PM CET:
> Autoconf version 2.59

Please note that current is 2.61, and also that it has some changes in
the _AS_LN_S_PREPARE macro, which is the one under consideration.

> Creating a configure script with autoconf produces the following check for
> symbolic links:
[...]

> My question is, why does it execute:
> ln -s conf$$.file conf$$
> and then test a file:
> test -f conf$$.exe

Because (quoting a comment from current Autoconf):
| # 2) DJGPP < 2.04 has no symlinks; `ln -s' creates a wrapper executable.

and we do not want that.

> The ".exe" here could be a bug and the "test -f conf$$.exe" seems to be
> false always in this case (the file does not exist so it is not a regular
> file.

Except on some DJGPP versions.

> Because it is false it is always assumed that ln -s can be used.

No.  That part of the code is executed only if the 'ln -s' succeeded in
the first place.

The current code also rejects MSYS 'ln -s', because while it emulates
symlinking of a file to another file fine (by 'cp -p'), it fails for
'ln -s file dir' and 'ln file dir'.

Hope that helps.

Cheers,
Ralf