Avoid fatal error condition in absint()

[josephscott]

In ​https://github.com/WordPress/wordpress-develop/commit/395dd7422b a return type of int was added to absint(). But the return value of abs() is never checked, and it can return a float - ​https://www.php.net/abs - which would result in a PHP fatal error condition.

As a general rule we should always check return values. In this case we need to do that to avoid a conflict with the return type.

This is trivial to trigger with ​http://localhost:8889/?author=-99999999999999999999

https://core.trac.wordpress.org/ticket/65826

AI assistance: Yes
Tool(s): Claude
Model(s): Opus 4.8
Used for: I had Claude update the tests

Hi @josephscott . Nice potential bug revealing. Can you consider an option to cast $maybeint into a separate variable and check the new variable if it is float? This would avoid an unnecessary call to the abs() function.

The test failures are unrelated. See ​https://wordpress.slack.com/archives/C02RQBWTW/p1786058519099039?thread_ts=1786057730.714189&cid=C02RQBWTW

Should be fixed by merging in the latest from trunk.

@dmsnell Yeah, this has opened a can of worms or gone down a rabbit hole… maybe a wormhole?

The issue is that absint() was previously broken previously in two ways:

1. Passing PHP_INT_MIN would actually cause the function to return a _float_!
2. Passing anything above PHP_INT_MAX (or below PHP_INT_MIN) would cause it to return int(0), and in PHP 8.5 a warning would also be emitted.

See ​https://3v4l.org/ZsvNQ#veol

For reference:

​https://github.com/WordPress/wordpress-develop/blob/2c261c16cd148b4e16d338e8abd59a027651c5f0/src/wp-includes/load.php#L1468-L1470

I tried your suggestion with fn ( $maybeint ) => min( PHP_INT_MAX, abs( (int) $maybeint ) ), but it doesn't seem improved: ​https://3v4l.org/VMXR3#v8.5.9

@westonruter @josephscott how about we revert the type annotation addition which caused the fatals to appear and then tackle this more complicated issue as an enhancement?

@dmsnell Yeah, I support that. Since we're now in RC, it makes sense.

@josephscott Could you create a new PR which cherry-picks your original commit e549981f76c4d92d644a54754c15a19224326d61? We can then leave this original PR open for the 7.2 bugfix. If you could open a Trac ticket too that would great.

Trac ticket: Core-65826
Replaces #12917

This reverts commit 395dd7422b1b569936bb8c0f9b90bf44d2044095.

When the return-type annotation was added to absint() it failed to recoginize that the function can return float as well. In the cases where it does this, WordPress started crashing requests.

Reverting remove the type constraint where PHP enforces it in order to avoid the fatal errors.

@westonruter I’ve proposed a revert of the original commit in #12940 so that we can step back and address this with more space to consider it.

The original patch on this PR introduced a small behavioral change, so I think it would be ideal to pull back for 7.1 and allow more opportunity for testing and review into 7.2.

Makes sense to me. Revert PR approved ✅

Closing in favor of #12940. Thanks @josephscott — I’ll merge the revert into 7.1 as soon as the CI tests pass.

I'll re-open this as it can serve as the basis for fixing the defect. If you want to start fresh, feel free to close again.

Might be worth starting a new PR for this, we can still reference https://core.trac.wordpress.org/ticket/65826

[dmsnell]

In 63158:

Docs: Revert "Indicate absint() returns non-negative-int...".

The introduction of a return-type annotation for absint() created fatal errors in cases where the function returns a float value. This resulted when the value passed into the function is smaller than PHP_INT_MIN. Since PHP’s int type is unable to represent the magnitude of that number in the positive, it returns a float value instead.

Reverting the type annotation prevents the crashing, but additional follow-up is warranted to ensure that the function produces the expected return types.

Developed in: ​https://github.com/WordPress/wordpress-develop/pull/12940
Discussed in: https://core.trac.wordpress.org/ticket/65826

Follow-up to [62647].

Props dmsnell, josephscott, westonruter.
Fixes #65826. See #64898.

With a long list of tests

https://core.trac.wordpress.org/ticket/65826

This will cause return values to change compared to the old absint() - ​https://3v4l.org/MssWC - because the old one wasn't actually limited to returning only an int

AI assistance: Yes
Tool(s): Claude
Model(s): Fable 5
Used for: Discussion on potential approaches on how to fix absint() to only return an int in a more simplified way. Claude also wrote all of the new tests.

[josephscott]

Took another attempt at making sure that absint() only returns an int - ​https://github.com/WordPress/wordpress-develop/pull/12944

After some rubber ducking with Claude how this might be done in a more simple fashion I ended up settling on this.

This will change the return values that absint() gives compared to the original version ​https://3v4l.org/MssWC - which I think is the right move given the name of the function, but has the potential to impact code that might have come to rely on absint() not always returning an int.

@westonruter @dmsnell

[westonruter]

Note: I've opened ​https://github.com/phpstan/phpstan/issues/15069 to report the issue where PHPStan was not flagging that abs( (int) $value ) can return a float.