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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.

As it happens, this version check never worked properly anyway, because "5.041006" ge "5.6.0" is false when it is intended to be true. This may come as a surprise to some users of this utility, who have been ignoring warnings for a long time and now suddenly cannot.

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.

As it happens, this version check never worked properly anyway, because
"5.041006" ge "5.6.0" is false when it is intended to be true.
This may come as a surprise to some users of this utility, who have been
ignoring warnings for a long time and now suddenly cannot.
@khwilliamson khwilliamson merged commit 3cb84a9 into master Dec 17, 2024
22 of 25 checks passed
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3 participants