fix string comparisons with $] to use numeric comparison instead

[book]

The fix follows Zefram's suggestion from
https://www.nntp.perl.org/group/perl.perl5.porters/2012/05/msg186846.html

On older perls, however, $] had a numeric value that was built up using
floating-point arithmetic, such as 5+0.006+0.000002. This would not
necessarily match the conversion of the complete value from string form
[perl #72210]. You can work around that by explicitly stringifying
$] (which produces a correct string) and having that numify (to a
correctly-converted floating point value) for comparison. I cultivate
the habit of always stringifying $] to work around this, regardless of
the threshold where the bug was fixed. So I'd write

use if "$]" >= 5.014, warnings => "non_unicode";

This ensures that the comparisons will still work when Perl's major version changes to anything greater than 9.

[Grinnz]

The changes don't seem to match the description here

[book]

The changes don't seem to match the description here

Indeed. This is extracted from a larger coming on perl/perl5 that I'm splitting and sending back to the various upstream repositories.

I'll push the commit again, with a more accurate message.

[haarg]

Pulling internals out of the version object is definitely wrong.

If perl dropped the 5 from the version, this would also be wrong. Binary compatibility would only be tied to the major version, not the minor version.

[book]

Pulling internals out of the version object is definitely wrong.

It did feel icky when I wrote it.

Would something like this be better?

$archname .= sprintf "-%d.%d", $^V =~ /v(\d+)\.(\d+)/;

[book]

If perl dropped the 5 from the version, this would also be wrong. Binary compatibility would only be tied to the major version, not the minor version.

Oh, you mean that for the hypothetical case where $^V is 41.8.0, only 41 should be used?

I think that I can only make that patch when the decision has actually been made. And then it's going to be an additional branch in the if/elsif bloc, anyway.

[book]

Closing this for now.

[haarg]

Oh, you mean that for the hypothetical case where $^V is 41.8.0, only 41 should be used?

Yes. Likely $Config{api_version}. $Config{api_revision} would be either dropped or left in place permanently as "5" like PERL_REVISION would be.

[haarg]

Actually, trying to abbreviate the version here seems wrong. It should just be using $Config{api_versionstring}.