…_postid()`.

As per the PHP manual:
> If the `component` parameter is omitted, an associative array is returned.
> If the `component` parameter is specified, `parse_url()` returns a string (or an int, in the case of `PHP_URL_PORT`) instead of an array. If the requested component doesn't exist within the given URL, `null` will be returned.

Reference: [https://www.php.net/manual/en/function.parse-url.php#refsect1-function.parse-url-returnvalues PHP Manual: parse_url(): Return Values]

In this case, `parse_url()` is called with `PHP_URL_HOST` as `$component`, which returns `null` if the URL only has a path. The return value of `parse_url()` was then passed to `str_replace()`, leading to a notice on PHP 8.1:
{{{
str_replace(): Passing null to parameter #3 ($subject) of type array|string is deprecated
}}}

Adding validation for the return type value of `parse_url()` prevents that.

This commit addresses a few errors in the test suite along the lines of:
{{{
5) Tests_Rewrite::test_url_to_postid_home_has_path
str_replace(): Passing null to parameter #3 ($subject) of type array|string is deprecated

/var/www/src/wp-includes/rewrite.php:503
/var/www/tests/phpunit/tests/rewrite.php:271
/var/www/vendor/bin/phpunit:123
}}}

Includes adding a dedicated unit test for a URL that only has a path.

Follow-up to [41786], [51606], [51622], [51626], [51629], [51630], [52799].

Props jrf, aristath, poena, justinahinon, SergeyBiryukov.
See #55656.

git-svn-id: https://develop.svn.wordpress.org/trunk@54364 602fd350-edb4-49c9-b593-d223f7449a82

This brings more consistency with other screens and avoids a PHP warning in `get_plugin_page_hookname()`:
{{{
preg_replace(): Passing null to parameter #3 ($subject) of type array|string is deprecated
}}}

Props ipajen, jrf, SergeyBiryukov.
Fixes #57578.

git-svn-id: https://develop.svn.wordpress.org/trunk@55263 602fd350-edb4-49c9-b593-d223f7449a82

The `$credentials['user_login']` and `$credentials['user_password']` parameters are passed by reference to the `wp_authenticate` action, and are at that point [https://www.php.net/manual/en/language.references.pass.php#124383 created as null] if they don't exist in the array.

This commit sets those values to an empty string, resolving two PHP 8.1 deprecation notices:
 * One from `preg_replace()` in `wp_strip_all_tags()` via `sanitize_user()` in `wp_authenticate()`:
{{{
Deprecated: preg_replace(): Passing null to parameter #3 ($subject) of type array|string is deprecated
}}}
 * One from `trim()` in `wp_authenticate()` itself:
{{{
Deprecated: trim(): Passing null to parameter #1 ($string) of type string is deprecated
}}}

Includes documenting the `$credentials` parameter using hash notation.

Follow-up to [6643], [37697].

Props lenasterg, TobiasBg, ocean90, afragen, lkraav, SergeyBiryukov.
Fixes #56850.

git-svn-id: https://develop.svn.wordpress.org/trunk@55301 602fd350-edb4-49c9-b593-d223f7449a82

…assic themes.

This brings more consistency with other screens and avoids a PHP warning in `get_plugin_page_hookname()`:
{{{
preg_replace(): Passing null to parameter #3 ($subject) of type array|string is deprecated
}}}

Follow-up to [13257], [13366], [55263].

Props nendeb55, costdev, SergeyBiryukov.
Fixes #57918.

git-svn-id: https://develop.svn.wordpress.org/trunk@55552 602fd350-edb4-49c9-b593-d223f7449a82

If the `$authordata` global is not set, `get_the_author()` returned `null`, causing a PHP 8.1 "null to non-nullable" deprecation notice in `ent2ncr()` hooked via `the_author` filter:
{{{
str_replace(): Passing null to parameter #3 ($subject) of type array|string is deprecated
}}}

This commit updates `get_the_author()` to return an empty string if called before `$authordata` is set, bringing consistency with a few other similar functions which also return an empty string in this case:

* `get_the_author_meta()`
* `get_the_author_posts_link()`
* `get_the_modified_author()`

Follow-up to [695/tests], [2858], [11138], [12284], [20575], [34677], [44616], [53187].

Props Soean, jrf, sabernhardt, salvoaranzulla, antpb, ebai4, sajjad67, tijmensmit, SergeyBiryukov.
Fixes #58157.

git-svn-id: https://develop.svn.wordpress.org/trunk@55755 602fd350-edb4-49c9-b593-d223f7449a82

…nitize_option()`.

When saving the settings via the admin UI, the default value for any options not passed in the current `$_POST` request is set to `null` in `wp-admin/options.php`. Some options, e.g. `blog_public`, then rely on `null` being passed to `update_option()` to determine whether the value was changed or not.

This commit resolves a PHP 8.1 deprecation notice when saving the `gmt_offset` option without any changes:
{{{
Deprecated: preg_replace(): Passing null to parameter #3 ($subject) of type array|string is deprecated
}}}

Includes a similar fix for the `blog_charset` option.

Follow-up to [4112], [4329], [5541], [21849].

Props adi3890, dhrupo, hrdelwar, hasanmisbah, oglekler, mukesh27, SergeyBiryukov.
Fixes #57728.

git-svn-id: https://develop.svn.wordpress.org/trunk@56132 602fd350-edb4-49c9-b593-d223f7449a82