Re: regression test filesystem assumptions

On Aug 7, 2013, at 12:23 PM, Nicholas Clark <[email protected]> wrote:

> I have this commit pushed to a smoke-me branch. It doesn't cause any =
test
> failures on the HP VMS testdrive system. Am I making bad assumptions?
>=20
> Specifically, is it filesystem dependant whether this code as-is will =
pass?
>=20
>    open(H,'run/fresh_perl.t'); # must be in the 't' directory
>    stat(H);
>    print "ok\n" if (-e _ and -f _ and -r _);
>=20

I can't think of any reason that would be different on different =
filesystems.

> I infer that it must have failed 12 years ago, because the last line =
was
> "corrected" to
>=20
>    print "ok\n" if (-e _ and -f _);
>=20
>=20
> But what changed to cause it to work now?
>=20

There have been various fixes to stat as well as to Perl_cando_by_name =
in vms/vms.c.  None I've managed to stumble on in the archives pops out =
as obviously "the one," and it would be arduous to do a manual bisect =
without git.

>=20
> Nicholas Clark
>=20
>=20
> commit 219b23a016e4d19b9fc29d2cb6aad7c8f485e7bc
> Author: Nicholas Clark <[email protected]>
> Date:   Wed Aug 7 11:57:09 2013 +0200
>=20
>    Remove the two "VMS adjustments" from test.pl's _fresh_perl
>=20
>    These were added by commit ed6b3797850720f7 ("make t/op/misc.t work =
on VMS")
>    in Jan 2001 back when the relevant code was in t/op/misc.t
>=20
>    The two adjustments each only applied to one test.
>=20
>    Was:    system './perl -ne "print if eof" /dev/null'
>    Became: system './perl -ne "print if eof" NL:'
>=20
>    Was:    print "ok\n" if (-e _ and -f _ and -r _);
>    Became: print "ok\n" if (-e _ and -f _);
>=20
>    The latter had the comment "VMS file locking".
>=20
>    It seems that neither is needed now. Perl will recognise =
"/dev/null" as
>    the null device, and -r returns true on a file opened for reading.
>=20
>    The "adjustments", particularly the second, should have been done =
all along
>    in the code for the test itself, not by complicating the test =
runner.
>=20
> diff --git a/t/test.pl b/t/test.pl
> index 89c1d4d..3662aa6 100644
> --- a/t/test.pl
> +++ b/t/test.pl
> @@ -848,16 +848,6 @@ sub _fresh_perl {
>     $runperl_args->{stderr}     =3D 1 unless exists =
$runperl_args->{stderr};
>=20
>     open TEST, ">$tmpfile" or die "Cannot open $tmpfile: $!";
> -
> -    # VMS adjustments
> -    if( $is_vms ) {
> -        $prog =3D~ s#/dev/null#NL:#;
> -
> -        # VMS file locking
> -        $prog =3D~ s{if \(-e _ and -f _ and -r _\)}
> -                  {if (-e _ and -f _)}
> -    }
> -
>     print TEST $prog;
>     close TEST or die "Cannot close $tmpfile: $!";
>=20

I think these changes are sane.  Once upon a time, the CRTL did not =
support /dev/null as an alias for the native _NLA0:.  I forget when =
/dev/null became supported; possibly v7.0, which was about 1995 or so.  =
I remember Chuck Lane, who wrote the misc.t patch, saying at some point =
that he was running v6.2, which was already somewhat old at the time.  I =
explicitly removed support for pre-7.0 VMS systems in Perl 5.16.x, so =
the /dev/null workaround seems safe to remove.

I think I disagree about whether these belonged in the test runner; that =
actually was the general place to solve a general problem, even if there =
weren't other extant tests that exercised the problem.  But those =
problems don't seem to be there now, so thanks for cleaning up after us.

________________________________________
Craig A. Berry
mailto:[email protected]

"... getting out of a sonnet is much more
 difficult than getting in."
                 Brad Leithauser