isset( $post->post_status ) && 'private' === $post->post_status ) {

			/* translators: %s: Private post title. */
			$prepend = __( 'Private: %s' );

			/**
			 * Filters the text prepended to the post title of private posts.
			 *
			 * The filter is only applied on the front end.
			 *
			 * @since 2.8.0
			 *
			 * @param string  $prepend Text displayed before the post title.
			 *                         Default 'Private: %s'.
			 * @param WP_Post $post    Current post object.
			 */
			$private_title_format = apply_filters( 'private_title_format', $prepend, $post );

			$post_title = sprintf( $private_title_format, $post_title );
		}
	}

	/**
	 * Filters the post title.
	 *
	 * @since 0.71
	 *
	 * @param string $post_title The post title.
	 * @param int    $post_id    The post ID.
	 */
	return apply_filters( 'the_title', $post_title, $post_id );
}

/**
 * Displays the Post Global Unique Identifier (guid).
 *
 * The guid will appear to be a link, but should not be used as a link to the
 * post. The reason you should not use it as a link, is because of moving the
 * blog across domains.
 *
 * URL is escaped to make it XML-safe.
 *
 * @since 1.5.0
 *
 * @param int|WP_Post $post Optional. Post ID or post object. Default is global $post.
 */
function the_guid( $post = 0 ) {
	$post = get_post( $post );

	$post_guid = isset( $post->guid ) ? get_the_guid( $post ) : '';
	$post_id   = $post->ID ?? 0;

	/**
	 * Filters the escaped Global Unique Identifier (guid) of the post.
	 *
	 * @since 4.2.0
	 *
	 * @see get_the_guid()
	 *
	 * @param string $post_guid Escaped Global Unique Identifier (guid) of the post.
	 * @param int    $post_id   The post ID.
	 */
	echo apply_filters( 'the_guid', $post_guid, $post_id );
}

/**
 * Retrieves the Post Global Unique Identifier (guid).
 *
 * The guid will appear to be a link, but should not be used as an link to the
 * post. The reason you should not use it as a link, is because of moving the
 * blog across domains.
 *
 * @since 1.5.0
 *
 * @param int|WP_Post $post Optional. Post ID or post object. Default is global $post.
 * @return string
 */
function get_the_guid( $post = 0 ) {
	$post = get_post( $post );

	$post_guid = $post->guid ?? '';
	$post_id   = $post->ID ?? 0;

	/**
	 * Filters the Global Unique Identifier (guid) of the post.
	 *
	 * @since 1.5.0
	 *
	 * @param string $post_guid Global Unique Identifier (guid) of the post.
	 * @param int    $post_id   The post ID.
	 */
	return apply_filters( 'get_the_guid', $post_guid, $post_id );
}

/**
 * Displays the post content.
 *
 * @since 0.71
 *
 * @param string $more_link_text Optional. Content for when there is more text.
 * @param bool   $strip_teaser   Optional. Strip teaser content before the more text. Default false.
 */
function the_content( $more_link_text = null, $strip_teaser = false ) {
	$content = get_the_content( $more_link_text, $strip_teaser );

	/**
	 * Filters the post content.
	 *
	 * @since 0.71
	 *
	 * @param string $content Content of the current post.
	 */
	$content = apply_filters( 'the_content', $content );
	$content = str_replace( ']]>', ']]>', $content );
	echo $content;
}

/**
 * Retrieves the post content.
 *
 * @since 0.71
 * @since 5.2.0 Added the `$post` parameter.
 *
 * @global int   $page      Page number of a single post/page.
 * @global int   $more      Boolean indicator for whether single post/page is being viewed.
 * @global bool  $preview   Whether post/page is in preview mode.
 * @global array $pages     Array of all pages in post/page. Each array element contains
 *                          part of the content separated by the `<!--nextpage-->` tag.
 * @global int   $multipage Boolean indicator for whether multiple pages are in play.
 *
 * @param string             $more_link_text Optional. Content for when there is more text.
 * @param bool               $strip_teaser   Optional. Strip teaser content before the more text. Default false.
 * @param WP_Post|object|int $post           Optional. WP_Post instance or Post ID/object. Default null.
 * @return string
 */
function get_the_content( $more_link_text = null, $strip_teaser = false, $post = null ) {
	global $page, $more, $preview, $pages, $multipage;

	$_post = get_post( $post );

	if ( ! ( $_post instanceof WP_Post ) ) {
		return '';
	}

	/*
	 * Use the globals if the $post parameter was not specified,
	 * but only after they have been set up in setup_postdata().
	 */
	if ( null === $post && did_action( 'the_post' ) ) {
		$elements = compact( 'page', 'more', 'preview', 'pages', 'multipage' );
	} else {
		$elements = generate_postdata( $_post );
	}

	if ( null === $more_link_text ) {
		$more_link_text = sprintf(
			'<span aria-label="%1$s">%2$s</span>',
			sprintf(
				/* translators: %s: Post title. */
				__( 'Continue reading %s' ),
				the_title_attribute(
					array(
						'echo' => false,
						'post' => $_post,
					)
				)
			),
			__( '(more&hellip;)' )
		);
	}

	$output     = '';
	$has_teaser = false;

	// If post password required and it doesn't match the cookie.
	if ( post_password_required( $_post ) ) {
		return get_the_password_form( $_post );
	}

	// If the requested page doesn't exist.
	if ( $elements['page'] > count( $elements['pages'] ) ) {
		// Give them the highest numbered page that DOES exist.
		$elements['page'] = count( $elements['pages'] );
	}

	$page_no = $elements['page'];
	$content = $elements['pages'][ $page_no - 1 ];
	if ( preg_match( '/<!--more(.*?)?-->/', $content, $matches ) ) {
		if ( has_block( 'more', $content ) ) {
			// Remove the core/more block delimiters. They will be left over after $content is split up.
			$content = preg_replace( '/<!-- \/?wp:more(.*?) -->/', '', $content );
		}

		$content = explode( $matches[0], $content, 2 );

		if ( ! empty( $matches[1] ) && ! empty( $more_link_text ) ) {
			$more_link_text = strip_tags( wp_kses_no_null( trim( $matches[1] ) ) );
		}

		$has_teaser = true;
	} else {
		$content = array( $content );
	}

	if ( str_contains( $_post->post_content, '<!--noteaser-->' )
		&& ( ! $elements['multipage'] || 1 === $elements['page'] )
	) {
		$strip_teaser = true;
	}

	$teaser = $content[0];

	if ( $elements['more'] && $strip_teaser && $has_teaser ) {
		$teaser = '';
	}

	$output .= $teaser;

	if ( count( $content ) > 1 ) {
		if ( $elements['more'] ) {
			$output .= '<span id="more-' . $_post->ID . '"></span>' . $content[1];
		} else {
			if ( ! empty( $more_link_text ) ) {

				/**
				 * Filters the Read More link text.
				 *
				 * @since 2.8.0
				 *
				 * @param string $more_link_element Read More link element.
				 * @param string $more_link_text    Read More text.
				 */
				$output .= apply_filters( 'the_content_more_link', ' <a href="' . get_permalink( $_post ) . "#more-{$_post->ID}\" class=\"more-link\">$more_link_text</a>", $more_link_text );
			}
			$output = force_balance_tags( $output );
		}
	}

	return $output;
}

/**
 * Displays the post excerpt.
 *
 * @since 0.71
 */
function the_excerpt() {

	/**
	 * Filters the displayed post excerpt.
	 *
	 * @since 0.71
	 *
	 * @see get_the_excerpt()
	 *
	 * @param string $post_excerpt The post excerpt.
	 */
	echo apply_filters( 'the_excerpt', get_the_excerpt() );
}

/**
 * Retrieves the post excerpt.
 *
 * @since 0.71
 * @since 4.5.0 Introduced the `$post` parameter.
 *
 * @param int|WP_Post|null $post Optional. Post ID or WP_Post object. Default is global $post.
 * @return string Post excerpt.
 */
function get_the_excerpt( $post = null ) {
	if ( is_bool( $post ) ) {
		_deprecated_argument( __FUNCTION__, '2.3.0' );
	}

	$post = get_post( $post );
	if ( empty( $post ) ) {
		return '';
	}

	if ( post_password_required( $post ) ) {
		return __( 'There is no excerpt because this is a protected post.' );
	}

	/**
	 * Filters the retrieved post excerpt.
	 *
	 * @since 1.2.0
	 * @since 4.5.0 Introduced the `$post` parameter.
	 *
	 * @param string  $post_excerpt The post excerpt.
	 * @param WP_Post $post         Post object.
	 */
	return apply_filters( 'get_the_excerpt', $post->post_excerpt, $post );
}

/**
 * Determines whether the post has a custom excerpt.
 *
 * For more information on this and similar theme functions, check out
 * the {@link https://developer.wordpress.org/themes/basics/conditional-tags/
 * Conditional Tags} article in the Theme Developer Handbook.
 *
 * @since 2.3.0
 *
 * @param int|WP_Post $post Optional. Post ID or WP_Post object. Default is global $post.
 * @return bool True if the post has a custom excerpt, false otherwise.
 */
function has_excerpt( $post = 0 ) {
	$post = get_post( $post );
	return ( ! empty( $post->post_excerpt ) );
}

/**
 * Displays the classes for the post container element.
 *
 * @since 2.7.0
 *
 * @param string|string[]  $css_class Optional. One or more classes to add to the class list.
 *                                    Default empty.
 * @param int|WP_Post|null $post      Optional. Post ID or post object. Defaults to the global `$post`.
 */
function post_class( $css_class = '', $post = null ) {
	// Separates classes with a single space, collates classes for post DIV.
	echo 'class="' . esc_attr( implode( ' ', get_post_class( $css_class, $post ) ) ) . '"';
}

/**
 * Retrieves an array of the class names for the post container element.
 *
 * The class names are many:
 *
 *  - If the post has a post thumbnail, `has-post-thumbnail` is added as a class.
 *  - If the post is sticky, then the `sticky` class name is added.
 *  - The class `hentry` is always added to each post.
 *  - For each taxonomy that the post belongs to, a class will be added of the format
 *    `{$taxonomy}-{$slug}`, e.g. `category-foo` or `my_custom_taxonomy-bar`.
 *    The `post_tag` taxonomy is a special case; the class has the `tag-` prefix
 *    instead of `post_tag-`.
 *
 * All class names are passed through the filter, {@see 'post_class'}, followed by
 * `$css_class` parameter value, with the post ID as the last parameter.
 *
 * @since 2.7.0
 * @since 4.2.0 Custom taxonomy class names were added.
 *
 * @param string|string[]  $css_class Optional. Space-separated string or array of class names
 *                                    to add to the class list. Default empty.
 * @param int|WP_Post|null $post      Optional. Post ID or post object.
 * @return string[] Array of class names.
 */
function get_post_class( $css_class = '', $post = null ) {
	$post = get_post( $post );

	$classes = array();

	if ( $css_class ) {
		if ( ! is_array( $css_class ) ) {
			$css_class = preg_split( '#\s+#', $css_class );
		}
		$classes = array_map( 'esc_attr', $css_class );
	} else {
		// Ensure that we always coerce class to being an array.
		$css_class = array();
	}

	if ( ! $post ) {
		return $classes;
	}

	$classes[] = 'post-' . $post->ID;
	if ( ! is_admin() ) {
		$classes[] = $post->post_type;
	}
	$classes[] = 'type-' . $post->post_type;
	$classes[] = 'status-' . $post->post_status;

	// Post Format.
	if ( post_type_supports( $post->post_type, 'post-formats' ) ) {
		$post_format = get_post_format( $post->ID );

		if ( $post_format && ! is_wp_error( $post_format ) ) {
			$classes[] = 'format-' . sanitize_html_class( $post_format );
		} else {
			$classes[] = 'format-standard';
		}
	}

	$post_password_required = post_password_required( $post->ID );

	// Post requires password.
	if ( $post_password_required ) {
		$classes[] = 'post-password-required';
	} elseif ( ! empty( $post->post_password ) ) {
		$classes[] = 'post-password-protected';
	}

	// Post thumbnails.
	if ( current_theme_supports( 'post-thumbnails' ) && has_post_thumbnail( $post->ID ) && ! is_attachment( $post ) && ! $post_password_required ) {
		$classes[] = 'has-post-thumbnail';
	}

	// Sticky for Sticky Posts.
	if ( is_sticky( $post->ID ) ) {
		if ( is_home() && ! is_paged() ) {
			$classes[] = 'sticky';
		} elseif ( is_admin() ) {
			$classes[] = 'status-sticky';
		}
	}

	// hentry for hAtom compliance.
	$classes[] = 'hentry';

	// All public taxonomies.
	$taxonomies = get_taxonomies( array( 'public' => true ) );

	/**
	 * Filters the taxonomies to generate classes for each individual term.
	 *
	 * Default is all public taxonomies registered to the post type.
	 *
	 * @since 6.1.0
	 *
	 * @param string[] $taxonomies List of all taxonomy names to generate classes for.
	 * @param int      $post_id    The post ID.
	 * @param string[] $classes    An array of post class names.
	 * @param string[] $css_class  An array of additional class names added to the post.
	*/
	$taxonomies = apply_filters( 'post_class_taxonomies', $taxonomies, $post->ID, $classes, $css_class );

	foreach ( (array) $taxonomies as $taxonomy ) {
		if ( is_object_in_taxonomy( $post->post_type, $taxonomy ) ) {
			foreach ( (array) get_the_terms( $post->ID, $taxonomy ) as $term ) {
				if ( empty( $term->slug ) ) {
					continue;
				}

				$term_class = sanitize_html_class( $term->slug, $term->term_id );
				if ( is_numeric( $term_class ) || ! trim( $term_class, '-' ) ) {
					$term_class = $term->term_id;
				}

				// 'post_tag' uses the 'tag' prefix for backward compatibility.
				if ( 'post_tag' === $taxonomy ) {
					$classes[] = 'tag-' . $term_class;
				} else {
					$classes[] = sanitize_html_class( $taxonomy . '-' . $term_class, $taxonomy . '-' . $term->term_id );
				}
			}
		}
	}

	$classes = array_map( 'esc_attr', $classes );

	/**
	 * Filters the list of CSS class names for the current post.
	 *
	 * @since 2.7.0
	 *
	 * @param string[] $classes   An array of post class names.
	 * @param string[] $css_class An array of additional class names added to the post.
	 * @param int      $post_id   The post ID.
	 */
	$classes = apply_filters( 'post_class', $classes, $css_class, $post->ID );

	$classes = array_unique( $classes );
	$classes = array_values( $classes );

	return $classes;
}

/**
 * Displays the class names for the body element.
 *
 * @since 2.8.0
 *
 * @param string|string[] $css_class Optional. Space-separated string or array of class names
 *                                   to add to the class list. Default empty.
 */
function body_class( $css_class = '' ) {
	// Separates class names with a single space, collates class names for body element.
	echo 'class="' . esc_attr( implode( ' ', get_body_class( $css_class ) ) ) . '"';
}

/**
 * Retrieves an array of the class names for the body element.
 *
 * @since 2.8.0
 *
 * @global WP_Query $wp_query WordPress Query object.
 *
 * @param string|string[] $css_class Optional. Space-separated string or array of class names
 *                                   to add to the class list. Default empty.
 * @return string[] Array of class names.
 */
function get_body_class( $css_class = '' ) {
	global $wp_query;

	$classes = array();

	if ( is_rtl() ) {
		$classes[] = 'rtl';
	}

	if ( is_front_page() ) {
		$classes[] = 'home';
	}
	if ( is_home() ) {
		$classes[] = 'blog';
	}
	if ( is_privacy_policy() ) {
		$classes[] = 'privacy-policy';
	}
	if ( is_archive() ) {
		$classes[] = 'archive';
	}
	if ( is_date() ) {
		$classes[] = 'date';
	}
	if ( is_search() ) {
		$classes[] = 'search';
		$classes[] = $wp_query->posts ? 'search-results' : 'search-no-results';
	}
	if ( is_paged() ) {
		$classes[] = 'paged';
	}
	if ( is_attachment() ) {
		$classes[] = 'attachment';
	}
	if ( is_404() ) {
		$classes[] = 'error404';
	}

	if ( is_singular() ) {
		$post      = $wp_query->get_queried_object();
		$post_id   = $post->ID;
		$post_type = $post->post_type;

		$classes[] = 'wp-singular';

		if ( is_page_template() ) {
			$classes[] = "{$post_type}-template";

			$template_slug  = get_page_template_slug( $post_id );
			$template_parts = explode( '/', $template_slug );

			foreach ( $template_parts as $part ) {
				$classes[] = "{$post_type}-template-" . sanitize_html_class( str_replace( array( '.', '/' ), '-', basename( $part, '.php' ) ) );
			}
			$classes[] = "{$post_type}-template-" . sanitize_html_class( str_replace( '.', '-', $template_slug ) );
		} else {
			$classes[] = "{$post_type}-template-default";
		}

		if ( is_single() ) {
			$classes[] = 'single';
			if ( isset( $post->post_type ) ) {
				$classes[] = 'single-' . sanitize_html_class( $post->post_type, $post_id );
				$classes[] = 'postid-' . $post_id;

				// Post Format.
				if ( post_type_supports( $post->post_type, 'post-formats' ) ) {
					$post_format = get_post_format( $post->ID );

					if ( $post_format && ! is_wp_error( $post_format ) ) {
						$classes[] = 'single-format-' . sanitize_html_class( $post_format );
					} else {
						$classes[] = 'single-format-standard';
					}
				}
			}
		}

		if ( is_attachment() ) {
			$mime_type   = get_post_mime_type( $post_id );
			$mime_prefix = array( 'application/', 'image/', 'text/', 'audio/', 'video/', 'music/' );
			$classes[]   = 'attachmentid-' . $post_id;
			$classes[]   = 'attachment-' . str_replace( $mime_prefix, '', $mime_type );
		} elseif ( is_page() ) {
			$classes[] = 'page';
			$classes[] = 'page-id-' . $post_id;

			if ( get_pages(
				array(
					'parent' => $post_id,
					'number' => 1,
				)
			) ) {
				$classes[] = 'page-parent';
			}

			if ( $post->post_parent ) {
				$classes[] = 'page-child';
				$classes[] = 'parent-pageid-' . $post->post_parent;
			}
		}
	} elseif ( is_archive() ) {
		if ( is_post_type_archive() ) {
			$classes[] = 'post-type-archive';
			$post_type = get_query_var( 'post_type' );
			if ( is_array( $post_type ) ) {
				$post_type = reset( $post_type );
			}
			$classes[] = 'post-type-archive-' . sanitize_html_class( $post_type );
		} elseif ( is_author() ) {
			$author    = $wp_query->get_queried_object();
			$classes[] = 'author';
			if ( isset( $author->user_nicename ) ) {
				$classes[] = 'author-' . sanitize_html_class( $author->user_nicename, $author->ID );
				$classes[] = 'author-' . $author->ID;
			}
		} elseif ( is_category() ) {
			$cat       = $wp_query->get_queried_object();
			$classes[] = 'category';
			if ( isset( $cat->term_id ) ) {
				$cat_class = sanitize_html_class( $cat->slug, $cat->term_id );
				if ( is_numeric( $cat_class ) || ! trim( $cat_class, '-' ) ) {
					$cat_class = $cat->term_id;
				}

				$classes[] = 'category-' . $cat_class;
				$classes[] = 'category-' . $cat->term_id;
			}
		} elseif ( is_tag() ) {
			$tag       = $wp_query->get_queried_object();
			$classes[] = 'tag';
			if ( isset( $tag->term_id ) ) {
				$tag_class = sanitize_html_class( $tag->slug, $tag->term_id );
				if ( is_numeric( $tag_class ) || ! trim( $tag_class, '-' ) ) {
					$tag_class = $tag->term_id;
				}

				$classes[] = 'tag-' . $tag_class;
				$classes[] = 'tag-' . $tag->term_id;
			}
		} elseif ( is_tax() ) {
			$term = $wp_query->get_queried_object();
			if ( isset( $term->term_id ) ) {
				$term_class = sanitize_html_class( $term->slug, $term->term_id );
				if ( is_numeric( $term_class ) || ! trim( $term_class, '-' ) ) {
					$term_class = $term->term_id;
				}

				$classes[] = 'tax-' . sanitize_html_class( $term->taxonomy );
				$classes[] = 'term-' . $term_class;
				$classes[] = 'term-' . $term->term_id;
			}
		}
	}

	if ( is_user_logged_in() ) {
		$classes[] = 'logged-in';
	}

	if ( is_admin_bar_showing() ) {
		$classes[] = 'admin-bar';
		$classes[] = 'no-customize-support';
	}

	if ( current_theme_supports( 'custom-background' )
		&& ( get_background_color() !== get_theme_support( 'custom-background', 'default-color' ) || get_background_image() ) ) {
		$classes[] = 'custom-background';
	}

	if ( has_custom_logo() ) {
		$classes[] = 'wp-custom-logo';
	}

	if ( current_theme_supports( 'responsive-embeds' ) ) {
		$classes[] = 'wp-embed-responsive';
	}

	$page = $wp_query->get( 'page' );

	if ( ! $page || $page < 2 ) {
		$page = $wp_query->get( 'paged' );
	}

	if ( $page && $page > 1 && ! is_404() ) {
		$classes[] = 'paged-' . $page;

		if ( is_single() ) {
			$classes[] = 'single-paged-' . $page;
		} elseif ( is_page() ) {
			$classes[] = 'page-paged-' . $page;
		} elseif ( is_category() ) {
			$classes[] = 'category-paged-' . $page;
		} elseif ( is_tag() ) {
			$classes[] = 'tag-paged-' . $page;
		} elseif ( is_date() ) {
			$classes[] = 'date-paged-' . $page;
		} elseif ( is_author() ) {
			$classes[] = 'author-paged-' . $page;
		} elseif ( is_search() ) {
			$classes[] = 'search-paged-' . $page;
		} elseif ( is_post_type_archive() ) {
			$classes[] = 'post-type-paged-' . $page;
		}
	}

	$classes[] = 'wp-theme-' . sanitize_html_class( get_template() );
	if ( is_child_theme() ) {
		$classes[] = 'wp-child-theme-' . sanitize_html_class( get_stylesheet() );
	}

	if ( ! empty( $css_class ) ) {
		if ( ! is_array( $css_class ) ) {
			$css_class = preg_split( '#\s+#', $css_class );
		}
		$classes = array_merge( $classes, $css_class );
	} else {
		// Ensure that we always coerce class to being an array.
		$css_class = array();
	}

	$classes = array_map( 'esc_attr', $classes );

	/**
	 * Filters the list of CSS body class names for the current post or page.
	 *
	 * @since 2.8.0
	 *
	 * @param string[] $classes   An array of body class names.
	 * @param string[] $css_class An array of additional class names added to the body.
	 */
	$classes = apply_filters( 'body_class', $classes, $css_class );

	return array_unique( $classes );
}

/**
 * Determines whether the post requires password and whether a correct password has been provided.
 *
 * @since 2.7.0
 *
 * @param int|WP_Post|null $post An optional post. Global $post used if not provided.
 * @return bool false if a password is not required or the correct password cookie is present, true otherwise.
 */
function post_password_required( $post = null ) {
	$post = get_post( $post );

	if ( empty( $post->post_password ) ) {
		/** This filter is documented in wp-includes/post-template.php */
		return apply_filters( 'post_password_required', false, $post );
	}

	if ( ! isset( $_COOKIE[ 'wp-postpass_' . COOKIEHASH ] ) ) {
		/** This filter is documented in wp-includes/post-template.php */
		return apply_filters( 'post_password_required', true, $post );
	}

	require_once ABSPATH . WPINC . '/class-phpass.php';
	$hasher = new PasswordHash( 8, true );

	$hash = wp_unslash( $_COOKIE[ 'wp-postpass_' . COOKIEHASH ] );
	if ( ! str_starts_with( $hash, '$P$B' ) ) {
		$required = true;
	} else {
		$required = ! $hasher->CheckPassword( $post->post_password, $hash );
	}

	/**
	 * Filters whether a post requires the user to supply a password.
	 *
	 * @since 4.7.0
	 *
	 * @param bool    $required Whether the user needs to supply a password. True if password has not been
	 *                          provided or is incorrect, false if password has been supplied or is not required.
	 * @param WP_Post $post     Post object.
	 */
	return apply_filters( 'post_password_required', $required, $post );
}

//
// Page Template Functions for usage in Themes.
//

/**
 * The formatted output of a list of pages.
 *
 * Displays page links for paginated posts (i.e. including the `<!--nextpage-->`
 * Quicktag one or more times). This tag must be within The Loop.
 *
 * @since 1.2.0
 * @since 5.1.0 Added the `aria_current` argument.
 *
 * @global int $page
 * @global int $numpages
 * @global int $multipage
 * @global int $more
 *
 * @param string|array $args {
 *     Optional. Array or string of default arguments.
 *
 *     @type string       $before           HTML or text to prepend to each link. Default is `<p> Pages:`.
 *     @type string       $after            HTML or text to append to each link. Default is `</p>`.
 *     @type string       $link_before      HTML or text to prepend to each link, inside the `<a>` tag.
 *                                          Also prepended to the current item, which is not linked. Default empty.
 *     @type string       $link_after       HTML or text to append to each Pages link inside the `<a>` tag.
 *                                          Also appended to the current item, which is not linked. Default empty.
 *     @type string       $aria_current     The value for the aria-current attribute. Possible values are 'page',
 *                                          'step', 'location', 'date', 'time', 'true', 'false'. Default is 'page'.
 *     @type string       $next_or_number   Indicates whether page numbers should be used. Valid values are number
 *                                          and next. Default is 'number'.
 *     @type string       $separator        Text between pagination links. Default is ' '.
 *     @type string       $nextpagelink     Link text for the next page link, if available. Default is 'Next Page'.
 *     @type string       $previouspagelink Link text for the previous page link, if available. Default is 'Previous Page'.
 *     @type string       $pagelink         Format string for page numbers. The % in the parameter string will be
 *                                          replaced with the page number, so 'Page %' generates "Page 1", "Page 2", etc.
 *                                          Defaults to '%', just the page number.
 *     @type int|bool     $echo             Whether to echo or not. Accepts 1|true or 0|false. Default 1|true.
 * }
 * @return string Formatted output in HTML.
 */
function wp_link_pages( $args = '' ) {
	global $page, $numpages, $multipage, $more;

	$defaults = array(
		'before'           => '<p class="post-nav-links">' . __( 'Pages:' ),
		'after'            => '</p>',
		'link_before'      => '',
		'link_after'       => '',
		'aria_current'     => 'page',
		'next_or_number'   => 'number',
		'separator'        => ' ',
		'nextpagelink'     => __( 'Next page' ),
		'previouspagelink' => __( 'Previous page' ),
		'pagelink'         => '%',
		'echo'             => 1,
	);

	$parsed_args = wp_parse_args( $args, $defaults );

	/**
	 * Filters the arguments used in retrieving page links for paginated posts.
	 *
	 * @since 3.0.0
	 *
	 * @param array $parsed_args An array of page link arguments. See wp_link_pages()
	 *                           for information on accepted arguments.
	 */
	$parsed_args = apply_filters( 'wp_link_pages_args', $parsed_args );

	$output = '';
	if ( $multipage ) {
		if ( 'number' === $parsed_args['next_or_number'] ) {
			$output .= $parsed_args['before'];
			for ( $i = 1; $i <= $numpages; $i++ ) {
				$link = $parsed_args['link_before'] . str_replace( '%', $i, $parsed_args['pagelink'] ) . $parsed_args['link_after'];

				if ( $i !== $page || ! $more && 1 === $page ) {
					$link = _wp_link_page( $i ) . $link . '</a>';
				} elseif ( $i === $page ) {
					$link = '<span class="post-page-numbers current" aria-current="' . esc_attr( $parsed_args['aria_current'] ) . '">' . $link . '</span>';
				}

				/**
				 * Filters the HTML output of individual page number links.
				 *
				 * @since 3.6.0
				 *
				 * @param string $link The page number HTML output.
				 * @param int    $i    Page number for paginated posts' page links.
				 */
				$link = apply_filters( 'wp_link_pages_link', $link, $i );

				// Use the custom links separator beginning with the second link.
				$output .= ( 1 === $i ) ? ' ' : $parsed_args['separator'];
				$output .= $link;
			}
			$output .= $parsed_args['after'];
		} elseif ( $more ) {
			$output .= $parsed_args['before'];
			$prev    = $page - 1;
			if ( $prev > 0 ) {
				$link = _wp_link_page( $prev ) . $parsed_args['link_before'] . $parsed_args['previouspagelink'] . $parsed_args['link_after'] . '</a>';

				/** This filter is documented in wp-includes/post-template.php */
				$output .= apply_filters( 'wp_link_pages_link', $link, $prev );
			}
			$next = $page + 1;
			if ( $next <= $numpages ) {
				if ( $prev ) {
					$output .= $parsed_args['separator'];
				}
				$link = _wp_link_page( $next ) . $parsed_args['link_before'] . $parsed_args['nextpagelink'] . $parsed_args['link_after'] . '</a>';

				/** This filter is documented in wp-includes/post-template.php */
				$output .= apply_filters( 'wp_link_pages_link', $link, $next );
			}
			$output .= $parsed_args['after'];
		}
	}

	/**
	 * Filters the HTML output of page links for paginated posts.
	 *
	 * @since 3.6.0
	 *
	 * @param string       $output HTML output of paginated posts' page links.
	 * @param array|string $args   An array or query string of arguments. See wp_link_pages()
	 *                             for information on accepted arguments.
	 */
	$html = apply_filters( 'wp_link_pages', $output, $args );

	if ( $parsed_args['echo'] ) {
		echo $html;
	}
	return $html;
}

/**
 * Helper function for wp_link_pages().
 *
 * @since 3.1.0
 * @access private
 *
 * @global WP_Rewrite $wp_rewrite WordPress rewrite component.
 *
 * @param int $i Page number.
 * @return string Link.
 */
function _wp_link_page( $i ) {
	global $wp_rewrite;
	$post       = get_post();
	$query_args = array();

	if ( 1 === $i ) {
		$url = get_permalink();
	} else {
		if ( ! get_option( 'permalink_structure' ) || in_array( $post->post_status, array( 'draft', 'pending' ), true ) ) {
			$url = add_query_arg( 'page', $i, get_permalink() );
		} elseif ( 'page' === get_option( 'show_on_front' ) && (int) get_option( 'page_on_front' ) === $post->ID ) {
			$url = trailingslashit( get_permalink() ) . user_trailingslashit( "$wp_rewrite->pagination_base/" . $i, 'single_paged' );
		} else {
			$url = trailingslashit( get_permalink() ) . user_trailingslashit( $i, 'single_paged' );
		}
	}

	if ( is_preview() ) {

		if ( ( 'draft' !== $post->post_status ) && isset( $_GET['preview_id'], $_GET['preview_nonce'] ) ) {
			$query_args['preview_id']    = wp_unslash( $_GET['preview_id'] );
			$query_args['preview_nonce'] = wp_unslash( $_GET['preview_nonce'] );
		}

		$url = get_preview_post_link( $post, $query_args, $url );
	}

	return '<a href="' . esc_url( $url ) . '" class="post-page-numbers">';
}

//
// Post-meta: Custom per-post fields.
//

/**
 * Retrieves post custom meta data field.
 *
 * @since 1.5.0
 *
 * @param string $key Meta data key name.
 * @return array|string|false Array of values, or single value if only one element exists.
 *                            False if the key does not exist.
 */
function post_custom( $key = '' ) {
	$custom = get_post_custom();

	if ( ! isset( $custom[ $key ] ) ) {
		return false;
	} elseif ( 1 === count( $custom[ $key ] ) ) {
		return $custom[ $key ][0];
	} else {
		return $custom[ $key ];
	}
}

/**
 * Displays a list of post custom fields.
 *
 * @since 1.2.0
 *
 * @deprecated 6.0.2 Use get_post_meta() to retrieve post meta and render manually.
 */
function the_meta() {
	_deprecated_function( __FUNCTION__, '6.0.2', 'get_post_meta()' );
	$keys = get_post_custom_keys();
	if ( $keys ) {
		$li_html = '';
		foreach ( (array) $keys as $key ) {
			$keyt = trim( $key );
			if ( is_protected_meta( $keyt, 'post' ) ) {
				continue;
			}

			$values = array_map( 'trim', get_post_custom_values( $key ) );
			$value  = implode( ', ', $values );

			$html = sprintf(
				"<li><span class='post-meta-key'>%s</span> %s</li>\n",
				/* translators: %s: Post custom field name. */
				esc_html( sprintf( _x( '%s:', 'Post custom field name' ), $key ) ),
				esc_html( $value )
			);

			/**
			 * Filters the HTML output of the li element in the post custom fields list.
			 *
			 * @since 2.2.0
			 *
			 * @param string $html  The HTML output for the li element.
			 * @param string $key   Meta key.
			 * @param string $value Meta value.
			 */
			$li_html .= apply_filters( 'the_meta_key', $html, $key, $value );
		}

		if ( $li_html ) {
			echo "<ul class='post-meta'>\n{$li_html}</ul>\n";
		}
	}
}

//
// Pages.
//

/**
 * Retrieves or displays a list of pages as a dropdown (select list).
 *
 * @since 2.1.0
 * @since 4.2.0 The `$value_field` argument was added.
 * @since 4.3.0 The `$class` argument was added.
 *
 * @see get_pages()
 *
 * @param array|string $args {
 *     Optional. Array or string of arguments to generate a page dropdown. See get_pages() for additional arguments.
 *
 *     @type int          $depth                 Maximum depth. Default 0.
 *     @type int          $child_of              Page ID to retrieve child pages of. Default 0.
 *     @type int|string   $selected              Value of the option that should be selected. Default 0.
 *     @type bool|int     $echo                  Whether to echo or return the generated markup. Accepts 0, 1,
 *                                               or their bool equivalents. Default 1.
 *     @type string       $name                  Value for the 'name' attribute of the select element.
 *                                               Default 'page_id'.
 *     @type string       $id                    Value for the 'id' attribute of the select element.
 *     @type string       $class                 Value for the 'class' attribute of the select element. Default: none.
 *                                               Defaults to the value of `$name`.
 *     @type string       $show_option_none      Text to display for showing no pages. Default empty (does not display).
 *     @type string       $show_option_no_change Text to display for "no change" option. Default empty (does not display).
 *     @type string       $option_none_value     Value to use when no page is selected. Default empty.
 *     @type string       $value_field           Post field used to populate the 'value' attribute of the option
 *                                               elements. Accepts any valid post field. Default 'ID'.
 * }
 * @return string HTML dropdown list of pages.
 */
function wp_dropdown_pages( $args = '' ) {
	$defaults = array(
		'depth'                 => 0,
		'child_of'              => 0,
		'selected'              => 0,
		'echo'                  => 1,
		'name'                  => 'page_id',
		'id'                    => '',
		'class'                 => '',
		'show_option_none'      => '',
		'show_option_no_change' => '',
		'option_none_value'     => '',
		'value_field'           => 'ID',
	);

	$parsed_args = wp_parse_args( $args, $defaults );

	$pages  = get_pages( $parsed_args );
	$output = '';
	// Back-compat with old system where both id and name were based on $name argument.
	if ( empty( $parsed_args['id'] ) ) {
		$parsed_args['id'] = $parsed_args['name'];
	}

	if ( ! empty( $pages ) ) {
		$class = '';
		if ( ! empty( $parsed_args['class'] ) ) {
			$class = " class='" . esc_attr( $parsed_args['class'] ) . "'";
		}

		$output = "<select name='" . esc_attr( $parsed_args['name'] ) . "'" . $class . " id='" . esc_attr( $parsed_args['id'] ) . "'>\n";
		if ( $parsed_args['show_option_no_change'] ) {
			$output .= "\t<option value=\"-1\">" . $parsed_args['show_option_no_change'] . "</option>\n";
		}
		if ( $parsed_args['show_option_none'] ) {
			$output .= "\t<option value=\"" . esc_attr( $parsed_args['option_none_value'] ) . '">' . $parsed_args['show_option_none'] . "</option>\n";
		}
		$output .= walk_page_dropdown_tree( $pages, $parsed_args['depth'], $parsed_args );
		$output .= "</select>\n";
	}

	/**
	 * Filters the HTML output of a list of pages as a dropdown.
	 *
	 * @since 2.1.0
	 * @since 4.4.0 `$parsed_args` and `$pages` added as arguments.
	 *
	 * @param string    $output      HTML output for dropdown list of pages.
	 * @param array     $parsed_args The parsed arguments array. See wp_dropdown_pages()
	 *                               for information on accepted arguments.
	 * @param WP_Post[] $pages       Array of the page objects.
	 */
	$html = apply_filters( 'wp_dropdown_pages', $output, $parsed_args, $pages );

	if ( $parsed_args['echo'] ) {
		echo $html;
	}

	return $html;
}

/**
 * Retrieves or displays a list of pages (or hierarchical post type items) in list (li) format.
 *
 * @since 1.5.0
 * @since 4.7.0 Added the `item_spacing` argument.
 *
 * @see get_pages()
 *
 * @global WP_Query $wp_query WordPress Query object.
 *
 * @param array|string $args {
 *     Optional. Array or string of arguments to generate a list of pages. See get_pages() for additional arguments.
 *
 *     @type int          $child_of     Display only the sub-pages of a single page by ID. Default 0 (all pages).
 *     @type string       $authors      Comma-separated list of author IDs. Default empty (all authors).
 *     @type string       $date_format  PHP date format to use for the listed pages. Relies on the 'show_date' parameter.
 *                                      Default is the value of 'date_format' option.
 *     @type int          $depth        Number of levels in the hierarchy of pages to include in the generated list.
 *                                      Accepts -1 (any depth), 0 (all pages), 1 (top-level pages only), and n (pages to
 *                                      the given n depth). Default 0.
 *     @type bool         $echo         Whether or not to echo the list of pages. Default true.
 *     @type string       $exclude      Comma-separated list of page IDs to exclude. Default empty.
 *     @type array        $include      Comma-separated list of page IDs to include. Default empty.
 *     @type string       $link_after   Text or HTML to follow the page link label. Default null.
 *     @type string       $link_before  Text or HTML to precede the page link label. Default null.
 *     @type string       $post_type    Post type to query for. Default 'page'.
 *     @type string|array $post_status  Comma-separated list or array of post statuses to include. Default 'publish'.
 *     @type string       $show_date    Whether to display the page publish or modified date for each page. Accepts
 *                                      'modified' or any other value. An empty value hides the date. Default empty.
 *     @type string       $sort_column  Comma-separated list of column names to sort the pages by. Accepts 'post_author',
 *                                      'post_date', 'post_title', 'post_name', 'post_modified', 'post_modified_gmt',
 *                                      'menu_order', 'post_parent', 'ID', 'rand', or 'comment_count'. Default 'post_title'.
 *     @type string       $title_li     List heading. Passing a null or empty value will result in no heading, and the list
 *                                      will not be wrapped with unordered list `<ul>` tags. Default 'Pages'.
 *     @type string       $item_spacing Whether to preserve whitespace within the menu's HTML. Accepts 'preserve' or 'discard'.
 *                                      Default 'preserve'.
 *     @type Walker       $walker       Walker instance to use for listing pages. Default empty which results in a
 *                                      Walker_Page instance being used.
 * }
 * @return void|string Void if 'echo' argument is true, HTML list of pages if 'echo' is false.
 */
function wp_list_pages( $args = '' ) {
	$defaults = array(
		'depth'        => 0,
		'show_date'    => '',
		'date_format'  => get_option( 'date_format' ),
		'child_of'     => 0,
		'exclude'      => '',
		'title_li'     => __( 'Pages' ),
		'echo'         => 1,
		'authors'      => '',
		'sort_column'  => 'menu_order, post_title',
		'link_before'  => '',
		'link_after'   => '',
		'item_spacing' => 'preserve',
		'walker'       => '',
	);

	$parsed_args = wp_parse_args( $args, $defaults );

	if ( ! in_array( $parsed_args['item_spacing'], array( 'preserve', 'discard' ), true ) ) {
		// Invalid value, fall back to default.
		$parsed_args['item_spacing'] = $defaults['item_spacing'];
	}

	$output       = '';
	$current_page = 0;

	// Sanitize, mostly to keep spaces out.
	$parsed_args['exclude'] = preg_replace( '/[^0-9,]/', '', $parsed_args['exclude'] );

	// Allow plugins to filter an array of excluded pages (but don't put a nullstring into the array).
	$exclude_array = ( $parsed_args['exclude'] ) ? explode( ',', $parsed_args['exclude'] ) : array();

	/**
	 * Filters the array of pages to exclude from the pages list.
	 *
	 * @since 2.1.0
	 *
	 * @param string[] $exclude_array An array of page IDs to exclude.
	 */
	$parsed_args['exclude'] = implode( ',', apply_filters( 'wp_list_pages_excludes', $exclude_array ) );

	$parsed_args['hierarchical'] = 0;

	// Query pages.
	$pages = get_pages( $parsed_args );

	if ( ! empty( $pages ) ) {
		if ( $parsed_args['title_li'] ) {
			$output .= '<li class="pagenav">' . $parsed_args['title_li'] . '<ul>';
		}
		global $wp_query;
		if ( is_page() || is_attachment() || $wp_query->is_posts_page ) {
			$current_page = get_queried_object_id();
		} elseif ( is_singular() ) {
			$queried_object = get_queried_object();
			if ( is_post_type_hierarchical( $queried_object->post_type ) ) {
				$current_page = $queried_object->ID;
			}
		}

		$output .= walk_page_tree( $pages, $parsed_args['depth'], $current_page, $parsed_args );

		if ( $parsed_args['title_li'] ) {
			$output .= '</ul></li>';
		}
	}

	/**
	 * Filters the HTML output of the pages to list.
	 *
	 * @since 1.5.1
	 * @since 4.4.0 `$pages` added as arguments.
	 *
	 * @see wp_list_pages()
	 *
	 * @param string    $output      HTML output of the pages list.
	 * @param array     $parsed_args An array of page-listing arguments. See wp_list_pages()
	 *                               for information on accepted arguments.
	 * @param WP_Post[] $pages       Array of the page objects.
	 */
	$html = apply_filters( 'wp_list_pages', $output, $parsed_args, $pages );

	if ( $parsed_args['echo'] ) {
		echo $html;
	} else {
		return $html;
	}
}

/**
 * Displays or retrieves a list of pages with an optional home link.
 *
 * The arguments are listed below and part of the arguments are for wp_list_pages() function.
 * Check that function for more info on those arguments.
 *
 * @since 2.7.0
 * @since 4.4.0 Added `menu_id`, `container`, `before`, `after`, and `walker` arguments.
 * @since 4.7.0 Added the `item_spacing` argument.
 *
 * @param array|string $args {
 *     Optional. Array or string of arguments to generate a page menu. See wp_list_pages() for additional arguments.
 *
 *     @type string          $sort_column  How to sort the list of pages. Accepts post column names.
 *                                         Default 'menu_order, post_title'.
 *     @type string          $menu_id      ID for the div containing the page list. Default is empty string.
 *     @type string          $menu_class   Class to use for the element containing the page list. Default 'menu'.
 *     @type string          $container    Element to use for the element containing the page list. Default 'div'.
 *     @type bool            $echo         Whether to echo the list or return it. Accepts true (echo) or false (return).
 *                                         Default true.
 *     @type int|bool|string $show_home    Whether to display the link to the home page. Can just enter the text
 *                                         you'd like shown for the home link. 1|true defaults to 'Home'.
 *     @type string          $link_before  The HTML or text to prepend to $show_home text. Default empty.
 *     @type string          $link_after   The HTML or text to append to $show_home text. Default empty.
 *     @type string          $before       The HTML or text to prepend to the menu. Default is '<ul>'.
 *     @type string          $after        The HTML or text to append to the menu. Default is '</ul>'.
 *     @type string          $item_spacing Whether to preserve whitespace within the menu's HTML. Accepts 'preserve'
 *                                         or 'discard'. Default 'discard'.
 *     @type Walker          $walker       Walker instance to use for listing pages. Default empty which results in a
 *                                         Walker_Page instance being used.
 * }
 * @return void|string Void if 'echo' argument is true, HTML menu if 'echo' is false.
 */
function wp_page_menu( $args = array() ) {
	$defaults = array(
		'sort_column'  => 'menu_order, post_title',
		'menu_id'      => '',
		'menu_class'   => 'menu',
		'container'    => 'div',
		'echo'         => true,
		'link_before'  => '',
		'link_after'   => '',
		'before'       => '<ul>',
		'after'        => '</ul>',
		'item_spacing' => 'discard',
		'walker'       => '',
	);
	$args     = wp_parse_args( $args, $defaults );

	if ( ! in_array( $args['item_spacing'], array( 'preserve', 'discard' ), true ) ) {
		// Invalid value, fall back to default.
		$args['item_spacing'] = $defaults['item_spacing'];
	}

	if ( 'preserve' === $args['item_spacing'] ) {
		$t = "\t";
		$n = "\n";
	} else {
		$t = '';
		$n = '';
	}

	/**
	 * Filters the arguments used to generate a page-based menu.
	 *
	 * @since 2.7.0
	 *
	 * @see wp_page_menu()
	 *
	 * @param array $args An array of page menu arguments. See wp_page_menu()
	 *                    for information on accepted arguments.
	 */
	$args = apply_filters( 'wp_page_menu_args', $args );

	$menu = '';

	$list_args = $args;

	// Show Home in the menu.
	if ( ! empty( $args['show_home'] ) ) {
		if ( true === $args['show_home'] || '1' === $args['show_home'] || 1 === $args['show_home'] ) {
			$text = __( 'Home' );
		} else {
			$text = $args['show_home'];
		}
		$class = '';
		if ( is_front_page() && ! is_paged() ) {
			$class = 'class="current_page_item"';
		}
		$menu .= '<li ' . $class . '><a href="' . esc_url( home_url( '/' ) ) . '">' . $args['link_before'] . $text . $args['link_after'] . '</a></li>';
		// If the front page is a page, add it to the exclude list.
		if ( 'page' === get_option( 'show_on_front' ) ) {
			if ( ! empty( $list_args['exclude'] ) ) {
				$list_args['exclude'] .= ',';
			} else {
				$list_args['exclude'] = '';
			}
			$list_args['exclude'] .= get_option( 'page_on_front' );
		}
	}

	$list_args['echo']     = false;
	$list_args['title_li'] = '';
	$menu                 .= wp_list_pages( $list_args );

	$container = sanitize_text_field( $args['container'] );

	// Fallback in case `wp_nav_menu()` was called without a container.
	if ( empty( $container ) ) {
		$container = 'div';
	}

	if ( $menu ) {

		// wp_nav_menu() doesn't set before and after.
		if ( isset( $args['fallback_cb'] ) &&
			'wp_page_menu' === $args['fallback_cb'] &&
			'ul' !== $container ) {
			$args['before'] = "<ul>{$n}";
			$args['after']  = '</ul>';
		}

		$menu = $args['before'] . $menu . $args['after'];
	}

	$attrs = '';
	if ( ! empty( $args['menu_id'] ) ) {
		$attrs .= ' id="' . esc_attr( $args['menu_id'] ) . '"';
	}

	if ( ! empty( $args['menu_class'] ) ) {
		$attrs .= ' class="' . esc_attr( $args['menu_class'] ) . '"';
	}

	$menu = "<{$container}{$attrs}>" . $menu . "</{$container}>{$n}";

	/**
	 * Filters the HTML output of a page-based menu.
	 *
	 * @since 2.7.0
	 *
	 * @see wp_page_menu()
	 *
	 * @param string $menu The HTML output.
	 * @param array  $args An array of arguments. See wp_page_menu()
	 *                     for information on accepted arguments.
	 */
	$menu = apply_filters( 'wp_page_menu', $menu, $args );

	if ( $args['echo'] ) {
		echo $menu;
	} else {
		return $menu;
	}
}

//
// Page helpers.
//

/**
 * Retrieves HTML list content for page list.
 *
 * @uses Walker_Page to create HTML list content.
 * @since 2.1.0
 *
 * @param array $pages
 * @param int   $depth
 * @param int   $current_page
 * @param array $args
 * @return string
 */
function walk_page_tree( $pages, $depth, $current_page, $args ) {
	if ( empty( $args['walker'] ) ) {
		$walker = new Walker_Page();
	} else {
		/**
		 * @var Walker $walker
		 */
		$walker = $args['walker'];
	}

	foreach ( (array) $pages as $page ) {
		if ( $page->post_parent ) {
			$args['pages_with_children'][ $page->post_parent ] = true;
		}
	}

	return $walker->walk( $pages, $depth, $args, $current_page );
}

/**
 * Retrieves HTML dropdown (select) content for page list.
 *
 * @since 2.1.0
 * @since 5.3.0 Formalized the existing `...$args` parameter by adding it
 *              to the function signature.
 *
 * @uses Walker_PageDropdown to create HTML dropdown content.
 * @see Walker_PageDropdown::walk() for parameters and return description.
 *
 * @param mixed ...$args Elements array, maximum hierarchical depth and optional additional arguments.
 * @return string
 */
function walk_page_dropdown_tree( ...$args ) {
	if ( empty( $args[2]['walker'] ) ) { // The user's options are the third parameter.
		$walker = new Walker_PageDropdown();
	} else {
		/**
		 * @var Walker $walker
		 */
		$walker = $args[2]['walker'];
	}

	return $walker->walk( ...$args );
}

//
// Attachments.
//

/**
 * Displays an attachment page link using an image or icon.
 *
 * @since 2.0.0
 *
 * @param int|WP_Post $post       Optional. Post ID or post object.
 * @param bool        $fullsize   Optional. Whether to use full size. Default false.
 * @param bool        $deprecated Deprecated. Not used.
 * @param bool        $permalink Optional. Whether to include permalink. Default false.
 */
function the_attachment_link( $post = 0, $fullsize = false, $deprecated = false, $permalink = false ) {
	if ( ! empty( $deprecated ) ) {
		_deprecated_argument( __FUNCTION__, '2.5.0' );
	}

	if ( $fullsize ) {
		echo wp_get_attachment_link( $post, 'full', $permalink );
	} else {
		echo wp_get_attachment_link( $post, 'thumbnail', $permalink );
	}
}

/**
 * Retrieves an attachment page link using an image or icon, if possible.
 *
 * @since 2.5.0
 * @since 4.4.0 The `$post` parameter can now accept either a post ID or `WP_Post` object.
 *
 * @param int|WP_Post  $post      Optional. Post ID or post object.
 * @param string|int[] $size      Optional. Image size. Accepts any registered image size name, or an array
 *                                of width and height values in pixels (in that order). Default 'thumbnail'.
 * @param bool         $permalink Optional. Whether to add permalink to image. Default false.
 * @param bool         $icon      Optional. Whether the attachment is an icon. Default false.
 * @param string|false $text      Optional. Link text to use. Activated by passing a string, false otherwise.
 *                                Default false.
 * @param array|string $attr      Optional. Array or string of attributes. Default empty.
 * @return string HTML content.
 */
function wp_get_attachment_link( $post = 0, $size = 'thumbnail', $permalink = false, $icon = false, $text = false, $attr = '' ) {
	$_post = get_post( $post );

	if ( empty( $_post ) || ( 'attachment' !== $_post->post_type ) || ! wp_get_attachment_url( $_post->ID ) ) {
		return __( 'Missing Attachment' );
	}

	$url = wp_get_attachment_url( $_post->ID );

	if ( $permalink ) {
		$url = get_attachment_link( $_post->ID );
	}

	if ( $text ) {
		$link_text = $text;
	} elseif ( $size && 'none' !== $size ) {
		$link_text = wp_get_attachment_image( $_post->ID, $size, $icon, $attr );
	} else {
		$link_text = '';
	}

	if ( '' === trim( $link_text ) ) {
		$link_text = $_post->post_title;
	}

	if ( '' === trim( $link_text ) ) {
		$link_text = esc_html( pathinfo( get_attached_file( $_post->ID ), PATHINFO_FILENAME ) );
	}

	/**
	 * Filters the list of attachment link attributes.
	 *
	 * @since 6.2.0
	 *
	 * @param array $attributes An array of attributes for the link markup,
	 *                          keyed on the attribute name.
	 * @param int   $id         Post ID.
	 */
	$attributes = apply_filters( 'wp_get_attachment_link_attributes', array( 'href' => $url ), $_post->ID );

	$link_attributes = '';
	foreach ( $attributes as $name => $value ) {
		$value            = 'href' === $name ? esc_url( $value ) : esc_attr( $value );
		$link_attributes .= ' ' . esc_attr( $name ) . "='" . $value . "'";
	}

	$link_html = "<a$link_attributes>$link_text</a>";

	/**
	 * Filters a retrieved attachment page link.
	 *
	 * @since 2.7.0
	 * @since 5.1.0 Added the `$attr` parameter.
	 *
	 * @param string       $link_html The page link HTML output.
	 * @param int|WP_Post  $post      Post ID or object. Can be 0 for the current global post.
	 * @param string|int[] $size      Requested image size. Can be any registered image size name, or
	 *                                an array of width and height values in pixels (in that order).
	 * @param bool         $permalink Whether to add permalink to image. Default false.
	 * @param bool         $icon      Whether to include an icon.
	 * @param string|false $text      If string, will be link text.
	 * @param array|string $attr      Array or string of attributes.
	 */
	return apply_filters( 'wp_get_attachment_link', $link_html, $post, $size, $permalink, $icon, $text, $attr );
}

/**
 * Wraps attachment in paragraph tag before content.
 *
 * @since 2.0.0
 *
 * @param string $content
 * @return string
 */
function prepend_attachment( $content ) {
	$post = get_post();

	if ( empty( $post->post_type ) || 'attachment' !== $post->post_type ) {
		return $content;
	}

	if ( wp_attachment_is( 'video', $post ) ) {
		$meta = wp_get_attachment_metadata( get_the_ID() );
		$atts = array( 'src' => wp_get_attachment_url() );
		if ( ! empty( $meta['width'] ) && ! empty( $meta['height'] ) ) {
			$atts['width']  = (int) $meta['width'];
			$atts['height'] = (int) $meta['height'];
		}
		if ( has_post_thumbnail() ) {
			$atts['poster'] = wp_get_attachment_url( get_post_thumbnail_id() );
		}
		$p = wp_video_shortcode( $atts );
	} elseif ( wp_attachment_is( 'audio', $post ) ) {
		$p = wp_audio_shortcode( array( 'src' => wp_get_attachment_url() ) );
	} else {
		$p = '<p class="attachment">';
		// Show the medium sized image representation of the attachment if available, and link to the raw file.
		$p .= wp_get_attachment_link( 0, 'medium', false );
		$p .= '</p>';
	}

	/**
	 * Filters the attachment markup to be prepended to the post content.
	 *
	 * @since 2.0.0
	 *
	 * @see prepend_attachment()
	 *
	 * @param string $p The attachment HTML output.
	 */
	$p = apply_filters( 'prepend_attachment', $p );

	return "$p\n$content";
}

//
// Misc.
//

/**
 * Retrieves protected post password form content.
 *
 * @since 1.0.0
 *
 * @param int|WP_Post $post Optional. Post ID or WP_Post object. Default is global $post.
 * @return string HTML content for password form for password-protected post.
 */
function get_the_password_form( $post = 0 ) {
	$post                  = get_post( $post );
	$field_id              = 'pwbox-' . ( empty( $post->ID ) ? wp_rand() : $post->ID );
	$invalid_password      = '';
	$invalid_password_html = '';
	$aria                  = '';
	$class                 = '';
	$redirect_field        = '';

	// If the referrer is the same as the current request, the user has entered an invalid password.
	if ( ! empty( $post->ID ) && wp_get_raw_referer() === get_permalink( $post->ID ) && isset( $_COOKIE[ 'wp-postpass_' . COOKIEHASH ] ) ) {
		/**
		 * Filters the invalid password message shown on password-protected posts.
		 * The filter is only applied if the post is password-protected.
		 *
		 * @since 6.8.0
		 *
		 * @param string  $text The message shown to users when entering an invalid password.
		 * @param WP_Post $post Post object.
		 */
		$invalid_password      = apply_filters( 'the_password_form_incorrect_password', __( 'Invalid password.' ), $post );
		$invalid_password_html = '<div class="post-password-form-invalid-password" role="alert"><p id="error-' . $field_id . '">' . $invalid_password . '</p></div>';
		$aria                  = ' aria-describedby="error-' . $field_id . '"';
		$class                 = ' password-form-error';
	}

	if ( ! empty( $post->ID ) ) {
		$redirect_field = sprintf(
			'<input type="hidden" name="redirect_to" value="%s" />',
			esc_attr( get_permalink( $post->ID ) )
		);
	}

	$button_class         = '';
	$button_wrapper_open  = '';
	$button_wrapper_close = '';

	if ( wp_is_block_theme() ) {
		$button_class         = ' class="wp-block-button__link ' . wp_theme_get_element_class_name( 'button' ) . '"';
		$button_wrapper_open  = '<span class="wp-block-button">';
		$button_wrapper_close = '</span>';

		if ( wp_style_is( 'wp-block-button', 'registered' ) ) {
			wp_enqueue_style( 'wp-block-button' );
		}
	}

	$output = '<form action="' . esc_url( site_url( 'wp-login.php?action=postpass', 'login_post' ) ) . '" class="post-password-form' . $class . '" method="post">' . $redirect_field . $invalid_password_html . '
	<p>' . __( 'This content is password-protected. To view it, please enter the password below.' ) . '</p>
	<p><label for="' . $field_id . '">' . __( 'Password:' ) . ' <input name="post_password" id="' . $field_id . '" type="password" spellcheck="false" required size="20"' . $aria . ' /></label> ' . $button_wrapper_open . '<input type="submit" name="Submit"' . $button_class . ' value="' . esc_attr_x( 'Enter', 'post password form' ) . '" />' . $button_wrapper_close . '</p></form>
	';

	/**
	 * Filters the HTML output for the protected post password form.
	 *
	 * If modifying the password field, please note that the WordPress database schema
	 * limits the password field to 255 characters regardless of the value of the
	 * `minlength` or `maxlength` attributes or other validation that may be added to
	 * the input.
	 *
	 * @since 2.7.0
	 * @since 5.8.0 Added the `$post` parameter.
	 * @since 6.8.0 Added the `$invalid_password` parameter.
	 *
	 * @param string  $output           The password form HTML output.
	 * @param WP_Post $post             Post object.
	 * @param string  $invalid_password The invalid password message.
	 */
	return apply_filters( 'the_password_form', $output, $post, $invalid_password );
}

/**
 * Determines whether the current post uses a page template.
 *
 * This template tag allows you to determine if you are in a page template.
 * You can optionally provide a template filename or array of template filenames
 * and then the check will be specific to that template.
 *
 * For more information on this and similar theme functions, check out
 * the {@link https://developer.wordpress.org/themes/basics/conditional-tags/
 * Conditional Tags} article in the Theme Developer Handbook.
 *
 * @since 2.5.0
 * @since 4.2.0 The `$template` parameter was changed to also accept an array of page templates.
 * @since 4.7.0 Now works with any post type, not just pages.
 *
 * @param string|string[] $template The specific template filename or array of templates to match.
 * @return bool True on success, false on failure.
 */
function is_page_template( $template = '' ) {
	if ( ! is_singular() ) {
		return false;
	}

	$page_template = get_page_template_slug( get_queried_object_id() );

	if ( empty( $template ) ) {
		return (bool) $page_template;
	}

	if ( $template === $page_template ) {
		return true;
	}

	if ( is_array( $template ) ) {
		if ( ( in_array( 'default', $template, true ) && ! $page_template )
			|| in_array( $page_template, $template, true )
		) {
			return true;
		}
	}

	return ( 'default' === $template && ! $page_template );
}

/**
 * Gets the specific template filename for a given post.
 *
 * @since 3.4.0
 * @since 4.7.0 Now works with any post type, not just pages.
 *
 * @param int|WP_Post|null $post Optional. Post ID or WP_Post object. Default is global $post.
 * @return string|false Page template filename. Returns an empty string when the default page template
 *                      is in use. Returns false if the post does not exist.
 */
function get_page_template_slug( $post = null ) {
	$post = get_post( $post );

	if ( ! $post ) {
		return false;
	}

	$template = get_post_meta( $post->ID, '_wp_page_template', true );

	if ( ! $template || 'default' === $template ) {
		return '';
	}

	return $template;
}

/**
 * Retrieves formatted date timestamp of a revision (linked to that revisions's page).
 *
 * @since 2.6.0
 *
 * @param int|WP_Post $revision Revision ID or revision object.
 * @param bool        $link     Optional. Whether to link to revision's page. Default true.
 * @return string|false i18n formatted datetimestamp or localized 'Current Revision'.
 */
function wp_post_revision_title( $revision, $link = true ) {
	$revision = get_post( $revision );

	if ( ! $revision ) {
		return $revision;
	}

	if ( ! in_array( $revision->post_type, array( 'post', 'page', 'revision' ), true ) ) {
		return false;
	}

	/* translators: Revision date format, see https://www.php.net/manual/datetime.format.php */
	$datef = _x( 'F j, Y @ H:i:s', 'revision date format' );
	/* translators: %s: Revision date. */
	$autosavef = __( '%s [Autosave]' );
	/* translators: %s: Revision date. */
	$currentf = __( '%s [Current Revision]' );

	$date      = date_i18n( $datef, strtotime( $revision->post_modified ) );
	$edit_link = get_edit_post_link( $revision->ID );
	if ( $link && current_user_can( 'edit_post', $revision->ID ) && $edit_link ) {
		$date = "<a href='$edit_link'>$date</a>";
	}

	if ( ! wp_is_post_revision( $revision ) ) {
		$date = sprintf( $currentf, $date );
	} elseif ( wp_is_post_autosave( $revision ) ) {
		$date = sprintf( $autosavef, $date );
	}

	return $date;
}

/**
 * Retrieves formatted date timestamp of a revision (linked to that revisions's page).
 *
 * @since 3.6.0
 *
 * @param int|WP_Post $revision Revision ID or revision object.
 * @param bool        $link     Optional. Whether to link to revision's page. Default true.
 * @return string|false gravatar, user, i18n formatted datetimestamp or localized 'Current Revision'.
 */
function wp_post_revision_title_expanded( $revision, $link = true ) {
	$revision = get_post( $revision );

	if ( ! $revision ) {
		return $revision;
	}

	if ( ! in_array( $revision->post_type, array( 'post', 'page', 'revision' ), true ) ) {
		return false;
	}

	$author = get_the_author_meta( 'display_name', $revision->post_author );
	/* translators: Revision date format, see https://www.php.net/manual/datetime.format.php */
	$datef = _x( 'F j, Y @ H:i:s', 'revision date format' );

	$gravatar = get_avatar( $revision->post_author, 24 );

	$date      = date_i18n( $datef, strtotime( $revision->post_modified ) );
	$edit_link = get_edit_post_link( $revision->ID );
	if ( $link && current_user_can( 'edit_post', $revision->ID ) && $edit_link ) {
		$date = "<a href='$edit_link'>$date</a>";
	}

	$revision_date_author = sprintf(
		/* translators: Post revision title. 1: Author avatar, 2: Author name, 3: Time ago, 4: Date. */
		__( '%1$s %2$s, %3$s ago (%4$s)' ),
		$gravatar,
		$author,
		human_time_diff( strtotime( $revision->post_modified_gmt ) ),
		$date
	);

	/* translators: %s: Revision date with author avatar. */
	$autosavef = __( '%s [Autosave]' );
	/* translators: %s: Revision date with author avatar. */
	$currentf = __( '%s [Current Revision]' );

	if ( ! wp_is_post_revision( $revision ) ) {
		$revision_date_author = sprintf( $currentf, $revision_date_author );
	} elseif ( wp_is_post_autosave( $revision ) ) {
		$revision_date_author = sprintf( $autosavef, $revision_date_author );
	}

	/**
	 * Filters the formatted author and date for a revision.
	 *
	 * @since 4.4.0
	 *
	 * @param string  $revision_date_author The formatted string.
	 * @param WP_Post $revision             The revision object.
	 * @param bool    $link                 Whether to link to the revisions page, as passed into
	 *                                      wp_post_revision_title_expanded().
	 */
	return apply_filters( 'wp_post_revision_title_expanded', $revision_date_author, $revision, $link );
}

/**
 * Displays a list of a post's revisions.
 *
 * Can output either a UL with edit links or a TABLE with diff interface, and
 * restore action links.
 *
 * @since 2.6.0
 *
 * @param int|WP_Post $post Optional. Post ID or WP_Post object. Default is global $post.
 * @param string      $type 'all' (default), 'revision' or 'autosave'
 */
function wp_list_post_revisions( $post = 0, $type = 'all' ) {
	$post = get_post( $post );

	if ( ! $post ) {
		return;
	}

	// $args array with (parent, format, right, left, type) deprecated since 3.6.
	if ( is_array( $type ) ) {
		$type = ! empty( $type['type'] ) ? $type['type'] : $type;
		_deprecated_argument( __FUNCTION__, '3.6.0' );
	}

	$revisions = wp_get_post_revisions( $post->ID );

	if ( ! $revisions ) {
		return;
	}

	$rows = '';
	foreach ( $revisions as $revision ) {
		if ( ! current_user_can( 'read_post', $revision->ID ) ) {
			continue;
		}

		$is_autosave = wp_is_post_autosave( $revision );
		if ( ( 'revision' === $type && $is_autosave ) || ( 'autosave' === $type && ! $is_autosave ) ) {
			continue;
		}

		$rows .= "\t<li>" . wp_post_revision_title_expanded( $revision ) . "</li>\n";
	}

	echo "<div class='hide-if-js'><p>" . __( 'JavaScript must be enabled to use this feature.' ) . "</p></div>\n";

	echo "<ul class='post-revisions hide-if-no-js'>\n";
	echo $rows;
	echo '</ul>';
}

/**
 * Retrieves the parent post object for the given post.
 *
 * @since 5.7.0
 *
 * @param int|WP_Post|null $post Optional. Post ID or WP_Post object. Default is global $post.
 * @return WP_Post|null Parent post object, or null if there isn't one.
 */
function get_post_parent( $post = null ) {
	$wp_post = get_post( $post );
	return ! empty( $wp_post->post_parent ) ? get_post( $wp_post->post_parent ) : null;
}

/**
 * Returns whether the given post has a parent post.
 *
 * @since 5.7.0
 *
 * @param int|WP_Post|null $post Optional. Post ID or WP_Post object. Default is global $post.
 * @return bool Whether the post has a parent post.
 */
function has_post_parent( $post = null ) {
	return (bool) get_post_parent( $post );
}
int( $term ) ) {
				continue;
			}
		}

		if ( is_wp_error( $term_info ) ) {
			return $term_info;
		}

		$tt_ids[] = $term_info['term_taxonomy_id'];
	}

	if ( $tt_ids ) {
		$in_tt_ids = "'" . implode( "', '", $tt_ids ) . "'";

		/**
		 * Fires immediately before an object-term relationship is deleted.
		 *
		 * @since 2.9.0
		 * @since 4.7.0 Added the `$taxonomy` parameter.
		 *
		 * @param int    $object_id Object ID.
		 * @param array  $tt_ids    An array of term taxonomy IDs.
		 * @param string $taxonomy  Taxonomy slug.
		 */
		do_action( 'delete_term_relationships', $object_id, $tt_ids, $taxonomy );

		$deleted = $wpdb->query( $wpdb->prepare( "DELETE FROM $wpdb->term_relationships WHERE object_id = %d AND term_taxonomy_id IN ($in_tt_ids)", $object_id ) );

		wp_cache_delete( $object_id, $taxonomy . '_relationships' );
		wp_cache_set_terms_last_changed();

		/**
		 * Fires immediately after an object-term relationship is deleted.
		 *
		 * @since 2.9.0
		 * @since 4.7.0 Added the `$taxonomy` parameter.
		 *
		 * @param int    $object_id Object ID.
		 * @param array  $tt_ids    An array of term taxonomy IDs.
		 * @param string $taxonomy  Taxonomy slug.
		 */
		do_action( 'deleted_term_relationships', $object_id, $tt_ids, $taxonomy );

		wp_update_term_count( $tt_ids, $taxonomy );

		return (bool) $deleted;
	}

	return false;
}

/**
 * Makes term slug unique, if it isn't already.
 *
 * The `$slug` has to be unique global to every taxonomy, meaning that one
 * taxonomy term can't have a matching slug with another taxonomy term. Each
 * slug has to be globally unique for every taxonomy.
 *
 * The way this works is that if the taxonomy that the term belongs to is
 * hierarchical and has a parent, it will append that parent to the $slug.
 *
 * If that still doesn't return a unique slug, then it tries to append a number
 * until it finds a number that is truly unique.
 *
 * The only purpose for `$term` is for appending a parent, if one exists.
 *
 * @since 2.3.0
 *
 * @global wpdb $wpdb WordPress database abstraction object.
 *
 * @param string $slug The string that will be tried for a unique slug.
 * @param object $term The term object that the `$slug` will belong to.
 * @return string Will return a true unique slug.
 */
function wp_unique_term_slug( $slug, $term ) {
	global $wpdb;

	$needs_suffix  = true;
	$original_slug = $slug;

	// As of 4.1, duplicate slugs are allowed as long as they're in different taxonomies.
	if ( ! term_exists( $slug ) || get_option( 'db_version' ) >= 30133 && ! get_term_by( 'slug', $slug, $term->taxonomy ) ) {
		$needs_suffix = false;
	}

	/*
	 * If the taxonomy supports hierarchy and the term has a parent, make the slug unique
	 * by incorporating parent slugs.
	 */
	$parent_suffix = '';
	if ( $needs_suffix && is_taxonomy_hierarchical( $term->taxonomy ) && ! empty( $term->parent ) ) {
		$the_parent = $term->parent;
		while ( ! empty( $the_parent ) ) {
			$parent_term = get_term( $the_parent, $term->taxonomy );
			if ( is_wp_error( $parent_term ) || empty( $parent_term ) ) {
				break;
			}
			$parent_suffix .= '-' . $parent_term->slug;
			if ( ! term_exists( $slug . $parent_suffix ) ) {
				break;
			}

			if ( empty( $parent_term->parent ) ) {
				break;
			}
			$the_parent = $parent_term->parent;
		}
	}

	// If we didn't get a unique slug, try appending a number to make it unique.

	/**
	 * Filters whether the proposed unique term slug is bad.
	 *
	 * @since 4.3.0
	 *
	 * @param bool   $needs_suffix Whether the slug needs to be made unique with a suffix.
	 * @param string $slug         The slug.
	 * @param object $term         Term object.
	 */
	if ( apply_filters( 'wp_unique_term_slug_is_bad_slug', $needs_suffix, $slug, $term ) ) {
		if ( $parent_suffix ) {
			$slug .= $parent_suffix;
		}

		if ( ! empty( $term->term_id ) ) {
			$query = $wpdb->prepare( "SELECT slug FROM $wpdb->terms WHERE slug = %s AND term_id != %d", $slug, $term->term_id );
		} else {
			$query = $wpdb->prepare( "SELECT slug FROM $wpdb->terms WHERE slug = %s", $slug );
		}

		if ( $wpdb->get_var( $query ) ) { // phpcs:ignore WordPress.DB.PreparedSQL.NotPrepared
			$num = 2;
			do {
				$alt_slug = $slug . "-$num";
				++$num;
				$slug_check = $wpdb->get_var( $wpdb->prepare( "SELECT slug FROM $wpdb->terms WHERE slug = %s", $alt_slug ) );
			} while ( $slug_check );
			$slug = $alt_slug;
		}
	}

	/**
	 * Filters the unique term slug.
	 *
	 * @since 4.3.0
	 *
	 * @param string $slug          Unique term slug.
	 * @param object $term          Term object.
	 * @param string $original_slug Slug originally passed to the function for testing.
	 */
	return apply_filters( 'wp_unique_term_slug', $slug, $term, $original_slug );
}

/**
 * Updates term based on arguments provided.
 *
 * The `$args` will indiscriminately override all values with the same field name.
 * Care must be taken to not override important information need to update or
 * update will fail (or perhaps create a new term, neither would be acceptable).
 *
 * Defaults will set 'alias_of', 'description', 'parent', and 'slug' if not
 * defined in `$args` already.
 *
 * 'alias_of' will create a term group, if it doesn't already exist, and
 * update it for the `$term`.
 *
 * If the 'slug' argument in `$args` is missing, then the 'name' will be used.
 * If you set 'slug' and it isn't unique, then a WP_Error is returned.
 * If you don't pass any slug, then a unique one will be created.
 *
 * @since 2.3.0
 *
 * @global wpdb $wpdb WordPress database abstraction object.
 *
 * @param int          $term_id  The ID of the term.
 * @param string       $taxonomy The taxonomy of the term.
 * @param array        $args {
 *     Optional. Array of arguments for updating a term.
 *
 *     @type string $alias_of    Slug of the term to make this term an alias of.
 *                               Default empty string. Accepts a term slug.
 *     @type string $description The term description. Default empty string.
 *     @type int    $parent      The id of the parent term. Default 0.
 *     @type string $slug        The term slug to use. Default empty string.
 * }
 * @return array|WP_Error An array containing the `term_id` and `term_taxonomy_id`,
 *                        WP_Error otherwise.
 * @phpstan-param array{
 *     alias_of?: string,
 *     description?: string,
 *     parent?: non-negative-int,
 *     slug?: string|null,
 *     ...
 * } $args
 * @phpstan-return array{
 *     term_id: int,
 *     term_taxonomy_id: int,
 * }|WP_Error
 */
function wp_update_term( $term_id, $taxonomy, $args = array() ) {
	global $wpdb;

	if ( ! taxonomy_exists( $taxonomy ) ) {
		return new WP_Error( 'invalid_taxonomy', __( 'Invalid taxonomy.' ) );
	}

	$term_id = (int) $term_id;

	// First, get all of the original args.
	$term = get_term( $term_id, $taxonomy );

	if ( is_wp_error( $term ) ) {
		return $term;
	}

	if ( ! $term ) {
		return new WP_Error( 'invalid_term', __( 'Empty Term.' ) );
	}

	$term = (array) $term->data;

	// Escape data pulled from DB.
	$term = wp_slash( $term );

	// Merge old and new args with new args overwriting old ones.
	$args = array_merge( $term, $args );

	$defaults    = array(
		'alias_of'    => '',
		'description' => '',
		'parent'      => 0,
		'slug'        => '',
	);
	$args        = wp_parse_args( $args, $defaults );
	$args        = sanitize_term( $args, $taxonomy, 'db' );
	$parsed_args = $args;

	// expected_slashed ($name)
	$name        = wp_unslash( $args['name'] );
	$description = wp_unslash( $args['description'] );

	$parsed_args['name']        = $name;
	$parsed_args['description'] = $description;

	if ( '' === trim( $name ) ) {
		return new WP_Error( 'empty_term_name', __( 'A name is required for this term.' ) );
	}

	if ( (int) $parsed_args['parent'] > 0 && ! term_exists( (int) $parsed_args['parent'] ) ) {
		return new WP_Error( 'missing_parent', __( 'Parent term does not exist.' ) );
	}

	$empty_slug = false;
	if ( empty( $args['slug'] ) ) {
		$empty_slug = true;
		$slug       = sanitize_title( $name );
	} else {
		$slug = $args['slug'];
	}

	$parsed_args['slug'] = $slug;

	$term_group = $parsed_args['term_group'] ?? 0;
	if ( $args['alias_of'] ) {
		$alias = get_term_by( 'slug', $args['alias_of'], $taxonomy );
		if ( ! empty( $alias->term_group ) ) {
			// The alias we want is already in a group, so let's use that one.
			$term_group = $alias->term_group;
		} elseif ( ! empty( $alias->term_id ) ) {
			/*
			 * The alias is not in a group, so we create a new one
			 * and add the alias to it.
			 */
			$term_group = $wpdb->get_var( "SELECT MAX(term_group) FROM $wpdb->terms" ) + 1;

			wp_update_term(
				$alias->term_id,
				$taxonomy,
				array(
					'term_group' => $term_group,
				)
			);
		}

		$parsed_args['term_group'] = $term_group;
	}

	/**
	 * Filters the term parent.
	 *
	 * Hook to this filter to see if it will cause a hierarchy loop.
	 *
	 * @since 3.1.0
	 *
	 * @param int    $parent_term ID of the parent term.
	 * @param int    $term_id     Term ID.
	 * @param string $taxonomy    Taxonomy slug.
	 * @param array  $parsed_args An array of potentially altered update arguments for the given term.
	 * @param array  $args        Arguments passed to wp_update_term().
	 */
	$parent = (int) apply_filters( 'wp_update_term_parent', $args['parent'], $term_id, $taxonomy, $parsed_args, $args );

	// Check for duplicate slug.
	$duplicate = get_term_by( 'slug', $slug, $taxonomy );
	if ( $duplicate && $duplicate->term_id !== $term_id ) {
		/*
		 * If an empty slug was passed or the parent changed, reset the slug to something unique.
		 * Otherwise, bail.
		 */
		if ( $empty_slug || ( $parent !== (int) $term['parent'] ) ) {
			$slug = wp_unique_term_slug( $slug, (object) $args );
		} else {
			/* translators: %s: Taxonomy term slug. */
			return new WP_Error( 'duplicate_term_slug', sprintf( __( 'The slug &#8220;%s&#8221; is already in use by another term.' ), $slug ) );
		}
	}

	$tt_id = (int) $wpdb->get_var( $wpdb->prepare( "SELECT tt.term_taxonomy_id FROM $wpdb->term_taxonomy AS tt INNER JOIN $wpdb->terms AS t ON tt.term_id = t.term_id WHERE tt.taxonomy = %s AND t.term_id = %d", $taxonomy, $term_id ) );

	// Check whether this is a shared term that needs splitting.
	$_term_id = _split_shared_term( $term_id, $tt_id );
	if ( ! is_wp_error( $_term_id ) ) {
		$term_id = $_term_id;
	}

	/**
	 * Fires immediately before the given terms are edited.
	 *
	 * @since 2.9.0
	 * @since 6.1.0 The `$args` parameter was added.
	 *
	 * @param int    $term_id  Term ID.
	 * @param string $taxonomy Taxonomy slug.
	 * @param array  $args     Arguments passed to wp_update_term().
	 */
	do_action( 'edit_terms', $term_id, $taxonomy, $args );

	$data = compact( 'name', 'slug', 'term_group' );

	/**
	 * Filters term data before it is updated in the database.
	 *
	 * @since 4.7.0
	 *
	 * @param array  $data     Term data to be updated.
	 * @param int    $term_id  Term ID.
	 * @param string $taxonomy Taxonomy slug.
	 * @param array  $args     Arguments passed to wp_update_term().
	 */
	$data = apply_filters( 'wp_update_term_data', $data, $term_id, $taxonomy, $args );

	$wpdb->update( $wpdb->terms, $data, compact( 'term_id' ) );

	if ( empty( $slug ) ) {
		$slug = sanitize_title( $name, $term_id );
		$wpdb->update( $wpdb->terms, compact( 'slug' ), compact( 'term_id' ) );
	}

	/**
	 * Fires immediately after a term is updated in the database, but before its
	 * term-taxonomy relationship is updated.
	 *
	 * @since 2.9.0
	 * @since 6.1.0 The `$args` parameter was added.
	 *
	 * @param int    $term_id  Term ID.
	 * @param string $taxonomy Taxonomy slug.
	 * @param array  $args     Arguments passed to wp_update_term().
	 */
	do_action( 'edited_terms', $term_id, $taxonomy, $args );

	/**
	 * Fires immediate before a term-taxonomy relationship is updated.
	 *
	 * @since 2.9.0
	 * @since 6.1.0 The `$args` parameter was added.
	 *
	 * @param int    $tt_id    Term taxonomy ID.
	 * @param string $taxonomy Taxonomy slug.
	 * @param array  $args     Arguments passed to wp_update_term().
	 */
	do_action( 'edit_term_taxonomy', $tt_id, $taxonomy, $args );

	$wpdb->update( $wpdb->term_taxonomy, compact( 'term_id', 'taxonomy', 'description', 'parent' ), array( 'term_taxonomy_id' => $tt_id ) );

	/**
	 * Fires immediately after a term-taxonomy relationship is updated.
	 *
	 * @since 2.9.0
	 * @since 6.1.0 The `$args` parameter was added.
	 *
	 * @param int    $tt_id    Term taxonomy ID.
	 * @param string $taxonomy Taxonomy slug.
	 * @param array  $args     Arguments passed to wp_update_term().
	 */
	do_action( 'edited_term_taxonomy', $tt_id, $taxonomy, $args );

	/**
	 * Fires after a term has been updated, but before the term cache has been cleaned.
	 *
	 * The {@see 'edit_$taxonomy'} hook is also available for targeting a specific
	 * taxonomy.
	 *
	 * @since 2.3.0
	 * @since 6.1.0 The `$args` parameter was added.
	 *
	 * @param int    $term_id  Term ID.
	 * @param int    $tt_id    Term taxonomy ID.
	 * @param string $taxonomy Taxonomy slug.
	 * @param array  $args     Arguments passed to wp_update_term().
	 */
	do_action( 'edit_term', $term_id, $tt_id, $taxonomy, $args );

	/**
	 * Fires after a term in a specific taxonomy has been updated, but before the term
	 * cache has been cleaned.
	 *
	 * The dynamic portion of the hook name, `$taxonomy`, refers to the taxonomy slug.
	 *
	 * Possible hook names include:
	 *
	 *  - `edit_category`
	 *  - `edit_post_tag`
	 *
	 * @since 2.3.0
	 * @since 6.1.0 The `$args` parameter was added.
	 *
	 * @param int   $term_id Term ID.
	 * @param int   $tt_id   Term taxonomy ID.
	 * @param array $args    Arguments passed to wp_update_term().
	 */
	do_action( "edit_{$taxonomy}", $term_id, $tt_id, $args );

	/** This filter is documented in wp-includes/taxonomy.php */
	$term_id = apply_filters( 'term_id_filter', $term_id, $tt_id, $args );

	clean_term_cache( $term_id, $taxonomy );

	/**
	 * Fires after a term has been updated, and the term cache has been cleaned.
	 *
	 * The {@see 'edited_$taxonomy'} hook is also available for targeting a specific
	 * taxonomy.
	 *
	 * @since 2.3.0
	 * @since 6.1.0 The `$args` parameter was added.
	 *
	 * @param int    $term_id  Term ID.
	 * @param int    $tt_id    Term taxonomy ID.
	 * @param string $taxonomy Taxonomy slug.
	 * @param array  $args     Arguments passed to wp_update_term().
	 */
	do_action( 'edited_term', $term_id, $tt_id, $taxonomy, $args );

	/**
	 * Fires after a term for a specific taxonomy has been updated, and the term
	 * cache has been cleaned.
	 *
	 * The dynamic portion of the hook name, `$taxonomy`, refers to the taxonomy slug.
	 *
	 * Possible hook names include:
	 *
	 *  - `edited_category`
	 *  - `edited_post_tag`
	 *
	 * @since 2.3.0
	 * @since 6.1.0 The `$args` parameter was added.
	 *
	 * @param int   $term_id Term ID.
	 * @param int   $tt_id   Term taxonomy ID.
	 * @param array $args    Arguments passed to wp_update_term().
	 */
	do_action( "edited_{$taxonomy}", $term_id, $tt_id, $args );

	/** This action is documented in wp-includes/taxonomy.php */
	do_action( 'saved_term', $term_id, $tt_id, $taxonomy, true, $args );

	/** This action is documented in wp-includes/taxonomy.php */
	do_action( "saved_{$taxonomy}", $term_id, $tt_id, true, $args );

	return array(
		'term_id'          => $term_id,
		'term_taxonomy_id' => $tt_id,
	);
}

/**
 * Enables or disables term counting.
 *
 * @since 2.5.0
 *
 * @param bool $defer Optional. Enable if true, disable if false.
 * @return bool Whether term counting is enabled or disabled.
 */
function wp_defer_term_counting( $defer = null ) {
	static $_defer = false;

	if ( is_bool( $defer ) ) {
		$_defer = $defer;
		// Flush any deferred counts.
		if ( ! $defer ) {
			wp_update_term_count( null, null, true );
		}
	}

	return $_defer;
}

/**
 * Updates the amount of terms in taxonomy.
 *
 * If there is a taxonomy callback applied, then it will be called for updating
 * the count.
 *
 * The default action is to count what the amount of terms have the relationship
 * of term ID. Once that is done, then update the database.
 *
 * @since 2.3.0
 *
 * @param int|array $terms       The term_taxonomy_id of the terms.
 * @param string    $taxonomy    The context of the term.
 * @param bool      $do_deferred Whether to flush the deferred term counts too. Default false.
 * @return bool If no terms will return false, and if successful will return true.
 */
function wp_update_term_count( $terms, $taxonomy, $do_deferred = false ) {
	static $_deferred = array();

	if ( $do_deferred ) {
		foreach ( (array) array_keys( $_deferred ) as $tax ) {
			wp_update_term_count_now( $_deferred[ $tax ], $tax );
			unset( $_deferred[ $tax ] );
		}
	}

	if ( empty( $terms ) ) {
		return false;
	}

	if ( ! is_array( $terms ) ) {
		$terms = array( $terms );
	}

	if ( wp_defer_term_counting() ) {
		if ( ! isset( $_deferred[ $taxonomy ] ) ) {
			$_deferred[ $taxonomy ] = array();
		}
		$_deferred[ $taxonomy ] = array_unique( array_merge( $_deferred[ $taxonomy ], $terms ) );
		return true;
	}

	return wp_update_term_count_now( $terms, $taxonomy );
}

/**
 * Performs term count update immediately.
 *
 * @since 2.5.0
 *
 * @param array  $terms    The term_taxonomy_id of terms to update.
 * @param string $taxonomy The context of the term.
 * @return true Always true when complete.
 */
function wp_update_term_count_now( $terms, $taxonomy ) {
	$terms = array_map( 'intval', $terms );

	$taxonomy = get_taxonomy( $taxonomy );
	if ( ! empty( $taxonomy->update_count_callback ) ) {
		call_user_func( $taxonomy->update_count_callback, $terms, $taxonomy );
	} else {
		$object_types = (array) $taxonomy->object_type;
		foreach ( $object_types as &$object_type ) {
			if ( str_starts_with( $object_type, 'attachment:' ) ) {
				list( $object_type ) = explode( ':', $object_type );
			}
		}

		if ( array_filter( $object_types, 'post_type_exists' ) == $object_types ) {
			// Only post types are attached to this taxonomy.
			_update_post_term_count( $terms, $taxonomy );
		} else {
			// Default count updater.
			_update_generic_term_count( $terms, $taxonomy );
		}
	}

	clean_term_cache( $terms, '', false );

	return true;
}

//
// Cache.
//

/**
 * Removes the taxonomy relationship to terms from the cache.
 *
 * Will remove the entire taxonomy relationship containing term `$object_id`. The
 * term IDs have to exist within the taxonomy `$object_type` for the deletion to
 * take place.
 *
 * @since 2.3.0
 *
 * @global bool $_wp_suspend_cache_invalidation
 *
 * @see get_object_taxonomies() for more on $object_type.
 *
 * @param int|array    $object_ids  Single or list of term object ID(s).
 * @param array|string $object_type The taxonomy object type.
 */
function clean_object_term_cache( $object_ids, $object_type ) {
	global $_wp_suspend_cache_invalidation;

	if ( ! empty( $_wp_suspend_cache_invalidation ) ) {
		return;
	}

	if ( ! is_array( $object_ids ) ) {
		$object_ids = array( $object_ids );
	}

	$taxonomies = get_object_taxonomies( $object_type );

	foreach ( $taxonomies as $taxonomy ) {
		wp_cache_delete_multiple( $object_ids, "{$taxonomy}_relationships" );
	}

	wp_cache_set_terms_last_changed();

	/**
	 * Fires after the object term cache has been cleaned.
	 *
	 * @since 2.5.0
	 *
	 * @param array  $object_ids An array of object IDs.
	 * @param string $object_type Object type.
	 */
	do_action( 'clean_object_term_cache', $object_ids, $object_type );
}

/**
 * Removes all of the term IDs from the cache.
 *
 * @since 2.3.0
 *
 * @global wpdb $wpdb                           WordPress database abstraction object.
 * @global bool $_wp_suspend_cache_invalidation
 *
 * @param int|int[] $ids            Single or array of term IDs.
 * @param string    $taxonomy       Optional. Taxonomy slug. Can be empty, in which case the taxonomies of the passed
 *                                  term IDs will be used. Default empty.
 * @param bool      $clean_taxonomy Optional. Whether to clean taxonomy wide caches (true), or just individual
 *                                  term object caches (false). Default true.
 */
function clean_term_cache( $ids, $taxonomy = '', $clean_taxonomy = true ) {
	global $wpdb, $_wp_suspend_cache_invalidation;

	if ( ! empty( $_wp_suspend_cache_invalidation ) ) {
		return;
	}

	if ( ! is_array( $ids ) ) {
		$ids = array( $ids );
	}

	$taxonomies = array();
	// If no taxonomy, assume tt_ids.
	if ( empty( $taxonomy ) ) {
		$tt_ids = array_map( 'intval', $ids );
		$tt_ids = implode( ', ', $tt_ids );
		$terms  = $wpdb->get_results( "SELECT term_id, taxonomy FROM $wpdb->term_taxonomy WHERE term_taxonomy_id IN ($tt_ids)" );
		$ids    = array();

		foreach ( (array) $terms as $term ) {
			$taxonomies[] = $term->taxonomy;
			$ids[]        = $term->term_id;
		}
		wp_cache_delete_multiple( $ids, 'terms' );
		$taxonomies = array_unique( $taxonomies );
	} else {
		wp_cache_delete_multiple( $ids, 'terms' );
		$taxonomies = array( $taxonomy );
	}

	foreach ( $taxonomies as $taxonomy ) {
		if ( $clean_taxonomy ) {
			clean_taxonomy_cache( $taxonomy );
		}

		/**
		 * Fires once after each taxonomy's term cache has been cleaned.
		 *
		 * @since 2.5.0
		 * @since 4.5.0 Added the `$clean_taxonomy` parameter.
		 *
		 * @param array  $ids            An array of term IDs.
		 * @param string $taxonomy       Taxonomy slug.
		 * @param bool   $clean_taxonomy Whether or not to clean taxonomy-wide caches
		 */
		do_action( 'clean_term_cache', $ids, $taxonomy, $clean_taxonomy );
	}

	wp_cache_set_terms_last_changed();
}

/**
 * Cleans the caches for a taxonomy.
 *
 * @since 4.9.0
 *
 * @param string $taxonomy Taxonomy slug.
 */
function clean_taxonomy_cache( $taxonomy ) {
	wp_cache_delete( 'all_ids', $taxonomy );
	wp_cache_delete( 'get', $taxonomy );
	wp_cache_set_terms_last_changed();

	// Regenerate cached hierarchy.
	if ( is_taxonomy_hierarchical( $taxonomy ) ) {
		delete_option( "{$taxonomy}_children" );
		_get_term_hierarchy( $taxonomy );
	}

	/**
	 * Fires after a taxonomy's caches have been cleaned.
	 *
	 * @since 4.9.0
	 *
	 * @param string $taxonomy Taxonomy slug.
	 */
	do_action( 'clean_taxonomy_cache', $taxonomy );
}

/**
 * Retrieves the cached term objects for the given object ID.
 *
 * Upstream functions (like get_the_terms() and is_object_in_term()) are
 * responsible for populating the object-term relationship cache. The current
 * function only fetches relationship data that is already in the cache.
 *
 * @since 2.3.0
 * @since 4.7.0 Returns a `WP_Error` object if there's an error with
 *              any of the matched terms.
 *
 * @param int    $id       Term object ID, for example a post, comment, or user ID.
 * @param string $taxonomy Taxonomy name.
 * @return bool|WP_Term[]|WP_Error Array of `WP_Term` objects, if cached.
 *                                 False if cache is empty for `$taxonomy` and `$id`.
 *                                 WP_Error if get_term() returns an error object for any term.
 */
function get_object_term_cache( $id, $taxonomy ) {
	$_term_ids = wp_cache_get( $id, "{$taxonomy}_relationships" );

	// We leave the priming of relationship caches to upstream functions.
	if ( false === $_term_ids ) {
		return false;
	}

	// Backward compatibility for if a plugin is putting objects into the cache, rather than IDs.
	$term_ids = array();
	foreach ( $_term_ids as $term_id ) {
		if ( is_numeric( $term_id ) ) {
			$term_ids[] = (int) $term_id;
		} elseif ( isset( $term_id->term_id ) ) {
			$term_ids[] = (int) $term_id->term_id;
		}
	}

	// Fill the term objects.
	_prime_term_caches( $term_ids );

	$terms = array();
	foreach ( $term_ids as $term_id ) {
		$term = get_term( $term_id, $taxonomy );
		if ( is_wp_error( $term ) ) {
			return $term;
		}

		$terms[] = $term;
	}

	return $terms;
}

/**
 * Updates the cache for the given term object ID(s).
 *
 * Note: Due to performance concerns, great care should be taken to only update
 * term caches when necessary. Processing time can increase exponentially depending
 * on both the number of passed term IDs and the number of taxonomies those terms
 * belong to.
 *
 * Caches will only be updated for terms not already cached.
 *
 * @since 2.3.0
 *
 * @param string|int[]    $object_ids  Comma-separated list or array of term object IDs.
 * @param string|string[] $object_type The taxonomy object type or array of the same.
 * @return void|false Void on success or if the `$object_ids` parameter is empty,
 *                    false if all of the terms in `$object_ids` are already cached.
 */
function update_object_term_cache( $object_ids, $object_type ) {
	if ( empty( $object_ids ) ) {
		return;
	}

	if ( ! is_array( $object_ids ) ) {
		$object_ids = explode( ',', $object_ids );
	}

	$object_ids     = array_map( 'intval', $object_ids );
	$non_cached_ids = array();

	$taxonomies = get_object_taxonomies( $object_type );

	foreach ( $taxonomies as $taxonomy ) {
		$cache_values = wp_cache_get_multiple( (array) $object_ids, "{$taxonomy}_relationships" );

		foreach ( $cache_values as $id => $value ) {
			if ( false === $value ) {
				$non_cached_ids[] = $id;
			}
		}
	}

	if ( empty( $non_cached_ids ) ) {
		return false;
	}

	$non_cached_ids = array_unique( $non_cached_ids );

	$terms = wp_get_object_terms(
		$non_cached_ids,
		$taxonomies,
		array(
			'fields'                 => 'all_with_object_id',
			'orderby'                => 'name',
			'update_term_meta_cache' => false,
		)
	);

	$object_terms = array();
	foreach ( (array) $terms as $term ) {
		$object_terms[ $term->object_id ][ $term->taxonomy ][] = $term->term_id;
	}

	foreach ( $non_cached_ids as $id ) {
		foreach ( $taxonomies as $taxonomy ) {
			if ( ! isset( $object_terms[ $id ][ $taxonomy ] ) ) {
				if ( ! isset( $object_terms[ $id ] ) ) {
					$object_terms[ $id ] = array();
				}
				$object_terms[ $id ][ $taxonomy ] = array();
			}
		}
	}

	$cache_values = array();
	foreach ( $object_terms as $id => $value ) {
		foreach ( $value as $taxonomy => $terms ) {
			$cache_values[ $taxonomy ][ $id ] = $terms;
		}
	}
	foreach ( $cache_values as $taxonomy => $data ) {
		wp_cache_add_multiple( $data, "{$taxonomy}_relationships" );
	}
}

/**
 * Updates terms in cache.
 *
 * @since 2.3.0
 *
 * @param WP_Term[] $terms    Array of term objects to change.
 * @param string    $taxonomy Not used.
 */
function update_term_cache( $terms, $taxonomy = '' ) {
	$data = array();
	foreach ( (array) $terms as $term ) {
		// Create a copy in case the array was passed by reference.
		$_term = clone $term;

		// Object ID should not be cached.
		unset( $_term->object_id );

		$data[ $term->term_id ] = $_term;
	}
	wp_cache_add_multiple( $data, 'terms' );
}

//
// Private.
//

/**
 * Retrieves children of taxonomy as term IDs.
 *
 * @access private
 * @since 2.3.0
 *
 * @param string $taxonomy Taxonomy name.
 * @return array Empty if $taxonomy isn't hierarchical or returns children as term IDs.
 */
function _get_term_hierarchy( $taxonomy ) {
	if ( ! is_taxonomy_hierarchical( $taxonomy ) ) {
		return array();
	}
	$children = get_option( "{$taxonomy}_children" );

	if ( is_array( $children ) ) {
		return $children;
	}
	$children = array();
	$terms    = get_terms(
		array(
			'taxonomy'               => $taxonomy,
			'get'                    => 'all',
			'orderby'                => 'id',
			'fields'                 => 'id=>parent',
			'update_term_meta_cache' => false,
		)
	);
	foreach ( $terms as $term_id => $parent ) {
		if ( $parent > 0 ) {
			$children[ $parent ][] = $term_id;
		}
	}
	update_option( "{$taxonomy}_children", $children );

	return $children;
}

/**
 * Gets the subset of $terms that are descendants of $term_id.
 *
 * If `$terms` is an array of objects, then _get_term_children() returns an array of objects.
 * If `$terms` is an array of IDs, then _get_term_children() returns an array of IDs.
 *
 * @access private
 * @since 2.3.0
 *
 * @param int    $term_id   The ancestor term: all returned terms should be descendants of `$term_id`.
 * @param array  $terms     The set of terms - either an array of term objects or term IDs - from which those that
 *                          are descendants of $term_id will be chosen.
 * @param string $taxonomy  The taxonomy which determines the hierarchy of the terms.
 * @param array  $ancestors Optional. Term ancestors that have already been identified. Passed by reference, to keep
 *                          track of found terms when recursing the hierarchy. The array of located ancestors is used
 *                          to prevent infinite recursion loops. For performance, `term_ids` are used as array keys,
 *                          with 1 as value. Default empty array.
 * @return array|WP_Error The subset of $terms that are descendants of $term_id.
 */
function _get_term_children( $term_id, $terms, $taxonomy, &$ancestors = array() ) {
	$empty_array = array();
	if ( empty( $terms ) ) {
		return $empty_array;
	}

	$term_id      = (int) $term_id;
	$term_list    = array();
	$has_children = _get_term_hierarchy( $taxonomy );

	if ( $term_id && ! isset( $has_children[ $term_id ] ) ) {
		return $empty_array;
	}

	// Include the term itself in the ancestors array, so we can properly detect when a loop has occurred.
	if ( empty( $ancestors ) ) {
		$ancestors[ $term_id ] = 1;
	}

	foreach ( (array) $terms as $term ) {
		$use_id = false;
		if ( ! is_object( $term ) ) {
			$term = get_term( $term, $taxonomy );
			if ( is_wp_error( $term ) ) {
				return $term;
			}
			$use_id = true;
		}

		// Don't recurse if we've already identified the term as a child - this indicates a loop.
		if ( isset( $ancestors[ $term->term_id ] ) ) {
			continue;
		}

		if ( (int) $term->parent === $term_id ) {
			if ( $use_id ) {
				$term_list[] = $term->term_id;
			} else {
				$term_list[] = $term;
			}

			if ( ! isset( $has_children[ $term->term_id ] ) ) {
				continue;
			}

			$ancestors[ $term->term_id ] = 1;

			$children = _get_term_children( $term->term_id, $terms, $taxonomy, $ancestors );
			if ( $children ) {
				$term_list = array_merge( $term_list, $children );
			}
		}
	}

	return $term_list;
}

/**
 * Adds count of children to parent count.
 *
 * Recalculates term counts by including items from child terms. Assumes all
 * relevant children are already in the $terms argument.
 *
 * @access private
 * @since 2.3.0
 *
 * @global wpdb $wpdb WordPress database abstraction object.
 *
 * @param object[]|WP_Term[] $terms    List of term objects (passed by reference).
 * @param string             $taxonomy Term context.
 */
function _pad_term_counts( &$terms, $taxonomy ) {
	global $wpdb;

	// This function only works for hierarchical taxonomies like post categories.
	if ( ! is_taxonomy_hierarchical( $taxonomy ) ) {
		return;
	}

	$term_hier = _get_term_hierarchy( $taxonomy );

	if ( empty( $term_hier ) ) {
		return;
	}

	$term_items  = array();
	$terms_by_id = array();
	$term_ids    = array();

	foreach ( (array) $terms as $key => $term ) {
		$terms_by_id[ $term->term_id ]       = & $terms[ $key ];
		$term_ids[ $term->term_taxonomy_id ] = $term->term_id;
	}

	// Get the object and term IDs and stick them in a lookup table.
	$tax_obj      = get_taxonomy( $taxonomy );
	$object_types = esc_sql( $tax_obj->object_type );
	$results      = $wpdb->get_results( "SELECT object_id, term_taxonomy_id FROM $wpdb->term_relationships INNER JOIN $wpdb->posts ON object_id = ID WHERE term_taxonomy_id IN (" . implode( ',', array_keys( $term_ids ) ) . ") AND post_type IN ('" . implode( "', '", $object_types ) . "') AND post_status = 'publish'" );

	foreach ( $results as $row ) {
		$id = $term_ids[ $row->term_taxonomy_id ];

		$term_items[ $id ][ $row->object_id ] = isset( $term_items[ $id ][ $row->object_id ] ) ? ++$term_items[ $id ][ $row->object_id ] : 1;
	}

	// Touch every ancestor's lookup row for each post in each term.
	foreach ( $term_ids as $term_id ) {
		$child     = $term_id;
		$ancestors = array();
		while ( ! empty( $terms_by_id[ $child ] ) && $parent = $terms_by_id[ $child ]->parent ) {
			$ancestors[] = $child;

			if ( ! empty( $term_items[ $term_id ] ) ) {
				foreach ( $term_items[ $term_id ] as $item_id => $touches ) {
					$term_items[ $parent ][ $item_id ] = isset( $term_items[ $parent ][ $item_id ] ) ? ++$term_items[ $parent ][ $item_id ] : 1;
				}
			}

			$child = $parent;

			if ( in_array( $parent, $ancestors, true ) ) {
				break;
			}
		}
	}

	// Transfer the touched cells.
	foreach ( (array) $term_items as $id => $items ) {
		if ( isset( $terms_by_id[ $id ] ) ) {
			$terms_by_id[ $id ]->count = count( $items );
		}
	}
}

/**
 * Adds any terms from the given IDs to the cache that do not already exist in cache.
 *
 * @since 4.6.0
 * @since 6.1.0 This function is no longer marked as "private".
 * @since 6.3.0 Use wp_lazyload_term_meta() for lazy-loading of term meta.
 *
 * @global wpdb $wpdb WordPress database abstraction object.
 *
 * @param array $term_ids          Array of term IDs.
 * @param bool  $update_meta_cache Optional. Whether to update the meta cache. Default true.
 */
function _prime_term_caches( $term_ids, $update_meta_cache = true ) {
	global $wpdb;

	$non_cached_ids = _get_non_cached_ids( $term_ids, 'terms' );
	if ( ! empty( $non_cached_ids ) ) {
		$fresh_terms = $wpdb->get_results( sprintf( "SELECT t.*, tt.* FROM $wpdb->terms AS t INNER JOIN $wpdb->term_taxonomy AS tt ON t.term_id = tt.term_id WHERE t.term_id IN (%s)", implode( ',', array_map( 'intval', $non_cached_ids ) ) ) );

		update_term_cache( $fresh_terms );
	}

	if ( $update_meta_cache ) {
		wp_lazyload_term_meta( $term_ids );
	}
}

//
// Default callbacks.
//

/**
 * Updates term count based on object types of the current taxonomy.
 *
 * Private function for the default callback for post_tag and category
 * taxonomies.
 *
 * @access private
 * @since 2.3.0
 *
 * @global wpdb $wpdb WordPress database abstraction object.
 *
 * @param int[]       $terms    List of term taxonomy IDs.
 * @param WP_Taxonomy $taxonomy Current taxonomy object of terms.
 */
function _update_post_term_count( $terms, $taxonomy ) {
	global $wpdb;

	$object_types = (array) $taxonomy->object_type;

	foreach ( $object_types as &$object_type ) {
		list( $object_type ) = explode( ':', $object_type );
	}

	$object_types = array_unique( $object_types );

	$check_attachments = array_search( 'attachment', $object_types, true );
	if ( false !== $check_attachments ) {
		unset( $object_types[ $check_attachments ] );
		$check_attachments = true;
	}

	if ( $object_types ) {
		$object_types = esc_sql( array_filter( $object_types, 'post_type_exists' ) );
	}

	$post_statuses = array( 'publish' );

	/**
	 * Filters the post statuses for updating the term count.
	 *
	 * @since 5.7.0
	 *
	 * @param string[]    $post_statuses List of post statuses to include in the count. Default is 'publish'.
	 * @param WP_Taxonomy $taxonomy      Current taxonomy object.
	 */
	$post_statuses = esc_sql( apply_filters( 'update_post_term_count_statuses', $post_statuses, $taxonomy ) );

	foreach ( (array) $terms as $tt_id ) {
		$count = 0;

		// Attachments can be 'inherit' status, we need to base count off the parent's status if so.
		if ( $check_attachments ) {
			// phpcs:ignore WordPress.DB.PreparedSQLPlaceholders.QuotedDynamicPlaceholderGeneration
			$count += (int) $wpdb->get_var( $wpdb->prepare( "SELECT COUNT(*) FROM $wpdb->term_relationships, $wpdb->posts p1 WHERE p1.ID = $wpdb->term_relationships.object_id AND ( post_status IN ('" . implode( "', '", $post_statuses ) . "') OR ( post_status = 'inherit' AND post_parent > 0 AND ( SELECT post_status FROM $wpdb->posts WHERE ID = p1.post_parent ) IN ('" . implode( "', '", $post_statuses ) . "') ) ) AND post_type = 'attachment' AND term_taxonomy_id = %d", $tt_id ) );
		}

		if ( $object_types ) {
			// phpcs:ignore WordPress.DB.PreparedSQLPlaceholders.QuotedDynamicPlaceholderGeneration
			$count += (int) $wpdb->get_var( $wpdb->prepare( "SELECT COUNT(*) FROM $wpdb->term_relationships, $wpdb->posts WHERE $wpdb->posts.ID = $wpdb->term_relationships.object_id AND post_status IN ('" . implode( "', '", $post_statuses ) . "') AND post_type IN ('" . implode( "', '", $object_types ) . "') AND term_taxonomy_id = %d", $tt_id ) );
		}

		/**
		 * Fires when a term count is calculated, before it is updated in the database.
		 *
		 * @since 6.9.0
		 *
		 * @param int    $tt_id         Term taxonomy ID.
		 * @param string $taxonomy_name Taxonomy slug.
		 * @param int    $count         Term count.
		 */
		do_action( 'update_term_count', $tt_id, $taxonomy->name, $count );

		/** This action is documented in wp-includes/taxonomy.php */
		do_action( 'edit_term_taxonomy', $tt_id, $taxonomy->name, array() );
		$wpdb->update( $wpdb->term_taxonomy, compact( 'count' ), array( 'term_taxonomy_id' => $tt_id ) );

		/** This action is documented in wp-includes/taxonomy.php */
		do_action( 'edited_term_taxonomy', $tt_id, $taxonomy->name, array() );
	}
}

/**
 * Updates term count based on number of objects.
 *
 * Default callback for the 'link_category' taxonomy.
 *
 * @since 3.3.0
 *
 * @global wpdb $wpdb WordPress database abstraction object.
 *
 * @param int[]       $terms    List of term taxonomy IDs.
 * @param WP_Taxonomy $taxonomy Current taxonomy object of terms.
 */
function _update_generic_term_count( $terms, $taxonomy ) {
	global $wpdb;

	foreach ( (array) $terms as $term ) {
		$count = $wpdb->get_var( $wpdb->prepare( "SELECT COUNT(*) FROM $wpdb->term_relationships WHERE term_taxonomy_id = %d", $term ) );

		/** This action is documented in wp-includes/taxonomy.php */
		do_action( 'update_term_count', $term, $taxonomy->name, $count );

		/** This action is documented in wp-includes/taxonomy.php */
		do_action( 'edit_term_taxonomy', $term, $taxonomy->name, array() );
		$wpdb->update( $wpdb->term_taxonomy, compact( 'count' ), array( 'term_taxonomy_id' => $term ) );

		/** This action is documented in wp-includes/taxonomy.php */
		do_action( 'edited_term_taxonomy', $term, $taxonomy->name, array() );
	}
}

/**
 * Creates a new term for a term_taxonomy item that currently shares its term
 * with another term_taxonomy.
 *
 * @ignore
 * @since 4.2.0
 * @since 4.3.0 Introduced `$record` parameter. Also, `$term_id` and
 *              `$term_taxonomy_id` can now accept objects.
 *
 * @global wpdb $wpdb WordPress database abstraction object.
 *
 * @param int|object $term_id          ID of the shared term, or the shared term object.
 * @param int|object $term_taxonomy_id ID of the term_taxonomy item to receive a new term, or the term_taxonomy object
 *                                     (corresponding to a row from the term_taxonomy table).
 * @param bool       $record           Whether to record data about the split term in the options table. The recording
 *                                     process has the potential to be resource-intensive, so during batch operations
 *                                     it can be beneficial to skip inline recording and do it just once, after the
 *                                     batch is processed. Only set this to `false` if you know what you are doing.
 *                                     Default: true.
 * @return int|WP_Error When the current term does not need to be split (or cannot be split on the current
 *                      database schema), `$term_id` is returned. When the term is successfully split, the
 *                      new term_id is returned. A WP_Error is returned for miscellaneous errors.
 */
function _split_shared_term( $term_id, $term_taxonomy_id, $record = true ) {
	global $wpdb;

	if ( is_object( $term_id ) ) {
		$shared_term = $term_id;
		$term_id     = (int) $shared_term->term_id;
	}

	if ( is_object( $term_taxonomy_id ) ) {
		$term_taxonomy    = $term_taxonomy_id;
		$term_taxonomy_id = (int) $term_taxonomy->term_taxonomy_id;
	}

	// If there are no shared term_taxonomy rows, there's nothing to do here.
	$shared_tt_count = (int) $wpdb->get_var( $wpdb->prepare( "SELECT COUNT(*) FROM $wpdb->term_taxonomy tt WHERE tt.term_id = %d AND tt.term_taxonomy_id != %d", $term_id, $term_taxonomy_id ) );

	if ( ! $shared_tt_count ) {
		return $term_id;
	}

	/*
	 * Verify that the term_taxonomy_id passed to the function is actually associated with the term_id.
	 * If there's a mismatch, it may mean that the term is already split. Return the actual term_id from the db.
	 */
	$check_term_id = (int) $wpdb->get_var( $wpdb->prepare( "SELECT term_id FROM $wpdb->term_taxonomy WHERE term_taxonomy_id = %d", $term_taxonomy_id ) );
	if ( $check_term_id !== $term_id ) {
		return $check_term_id;
	}

	// Pull up data about the currently shared slug, which we'll use to populate the new one.
	if ( empty( $shared_term ) ) {
		$shared_term = $wpdb->get_row( $wpdb->prepare( "SELECT t.* FROM $wpdb->terms t WHERE t.term_id = %d", $term_id ) );
	}

	$new_term_data = array(
		'name'       => $shared_term->name,
		'slug'       => $shared_term->slug,
		'term_group' => $shared_term->term_group,
	);

	if ( false === $wpdb->insert( $wpdb->terms, $new_term_data ) ) {
		return new WP_Error( 'db_insert_error', __( 'Could not split shared term.' ), $wpdb->last_error );
	}

	$new_term_id = (int) $wpdb->insert_id;

	// Update the existing term_taxonomy to point to the newly created term.
	$wpdb->update(
		$wpdb->term_taxonomy,
		array( 'term_id' => $new_term_id ),
		array( 'term_taxonomy_id' => $term_taxonomy_id )
	);

	// Reassign child terms to the new parent.
	if ( empty( $term_taxonomy ) ) {
		$term_taxonomy = $wpdb->get_row( $wpdb->prepare( "SELECT * FROM $wpdb->term_taxonomy WHERE term_taxonomy_id = %d", $term_taxonomy_id ) );
	}

	$children_tt_ids = $wpdb->get_col( $wpdb->prepare( "SELECT term_taxonomy_id FROM $wpdb->term_taxonomy WHERE parent = %d AND taxonomy = %s", $term_id, $term_taxonomy->taxonomy ) );
	if ( ! empty( $children_tt_ids ) ) {
		foreach ( $children_tt_ids as $child_tt_id ) {
			$wpdb->update(
				$wpdb->term_taxonomy,
				array( 'parent' => $new_term_id ),
				array( 'term_taxonomy_id' => $child_tt_id )
			);
			clean_term_cache( (int) $child_tt_id, '', false );
		}
	} else {
		// If the term has no children, we must force its taxonomy cache to be rebuilt separately.
		clean_term_cache( $new_term_id, $term_taxonomy->taxonomy, false );
	}

	clean_term_cache( $term_id, $term_taxonomy->taxonomy, false );

	/*
	 * Taxonomy cache clearing is delayed to avoid race conditions that may occur when
	 * regenerating the taxonomy's hierarchy tree.
	 */
	$taxonomies_to_clean = array( $term_taxonomy->taxonomy );

	// Clean the cache for term taxonomies formerly shared with the current term.
	$shared_term_taxonomies = $wpdb->get_col( $wpdb->prepare( "SELECT taxonomy FROM $wpdb->term_taxonomy WHERE term_id = %d", $term_id ) );
	$taxonomies_to_clean    = array_merge( $taxonomies_to_clean, $shared_term_taxonomies );

	foreach ( $taxonomies_to_clean as $taxonomy_to_clean ) {
		clean_taxonomy_cache( $taxonomy_to_clean );
	}

	// Keep a record of term_ids that have been split, keyed by old term_id. See wp_get_split_term().
	if ( $record ) {
		$split_term_data = get_option( '_split_terms', array() );
		if ( ! isset( $split_term_data[ $term_id ] ) ) {
			$split_term_data[ $term_id ] = array();
		}

		$split_term_data[ $term_id ][ $term_taxonomy->taxonomy ] = $new_term_id;
		update_option( '_split_terms', $split_term_data );
	}

	// If we've just split the final shared term, set the "finished" flag.
	$shared_terms_exist = $wpdb->get_results(
		"SELECT tt.term_id, t.*, count(*) as term_tt_count FROM {$wpdb->term_taxonomy} tt
		 LEFT JOIN {$wpdb->terms} t ON t.term_id = tt.term_id
		 GROUP BY t.term_id
		 HAVING term_tt_count > 1
		 LIMIT 1"
	);
	if ( ! $shared_terms_exist ) {
		update_option( 'finished_splitting_shared_terms', true );
	}

	/**
	 * Fires after a previously shared taxonomy term is split into two separate terms.
	 *
	 * @since 4.2.0
	 *
	 * @param int    $term_id          ID of the formerly shared term.
	 * @param int    $new_term_id      ID of the new term created for the $term_taxonomy_id.
	 * @param int    $term_taxonomy_id ID for the term_taxonomy row affected by the split.
	 * @param string $taxonomy         Taxonomy for the split term.
	 */
	do_action( 'split_shared_term', $term_id, $new_term_id, $term_taxonomy_id, $term_taxonomy->taxonomy );

	return $new_term_id;
}

/**
 * Splits a batch of shared taxonomy terms.
 *
 * @since 4.3.0
 *
 * @global wpdb $wpdb WordPress database abstraction object.
 */
function _wp_batch_split_terms() {
	global $wpdb;

	$lock_name = 'term_split.lock';

	// Try to lock.
	$lock_result = $wpdb->query( $wpdb->prepare( "INSERT IGNORE INTO `$wpdb->options` ( `option_name`, `option_value`, `autoload` ) VALUES (%s, %s, 'off') /* LOCK */", $lock_name, time() ) );

	if ( ! $lock_result ) {
		$lock_result = get_option( $lock_name );

		// Bail if we were unable to create a lock, or if the existing lock is still valid.
		if ( ! $lock_result || ( $lock_result > ( time() - HOUR_IN_SECONDS ) ) ) {
			wp_schedule_single_event( time() + ( 5 * MINUTE_IN_SECONDS ), 'wp_split_shared_term_batch' );
			return;
		}
	}

	// Update the lock, as by this point we've definitely got a lock, just need to fire the actions.
	update_option( $lock_name, time() );

	// Get a list of shared terms (those with more than one associated row in term_taxonomy).
	$shared_terms = $wpdb->get_results(
		"SELECT tt.term_id, t.*, count(*) as term_tt_count FROM {$wpdb->term_taxonomy} tt
		 LEFT JOIN {$wpdb->terms} t ON t.term_id = tt.term_id
		 GROUP BY t.term_id
		 HAVING term_tt_count > 1
		 LIMIT 10"
	);

	// No more terms, we're done here.
	if ( ! $shared_terms ) {
		update_option( 'finished_splitting_shared_terms', true );
		delete_option( $lock_name );
		return;
	}

	// Shared terms found? We'll need to run this script again.
	wp_schedule_single_event( time() + ( 2 * MINUTE_IN_SECONDS ), 'wp_split_shared_term_batch' );

	// Rekey shared term array for faster lookups.
	$_shared_terms = array();
	foreach ( $shared_terms as $shared_term ) {
		$term_id                   = (int) $shared_term->term_id;
		$_shared_terms[ $term_id ] = $shared_term;
	}
	$shared_terms = $_shared_terms;

	// Get term taxonomy data for all shared terms.
	$shared_term_ids = implode( ',', array_keys( $shared_terms ) );
	$shared_tts      = $wpdb->get_results( "SELECT * FROM {$wpdb->term_taxonomy} WHERE `term_id` IN ({$shared_term_ids})" );

	// Split term data recording is slow, so we do it just once, outside the loop.
	$split_term_data    = get_option( '_split_terms', array() );
	$skipped_first_term = array();
	$taxonomies         = array();
	foreach ( $shared_tts as $shared_tt ) {
		$term_id = (int) $shared_tt->term_id;

		// Don't split the first tt belonging to a given term_id.
		if ( ! isset( $skipped_first_term[ $term_id ] ) ) {
			$skipped_first_term[ $term_id ] = 1;
			continue;
		}

		if ( ! isset( $split_term_data[ $term_id ] ) ) {
			$split_term_data[ $term_id ] = array();
		}

		// Keep track of taxonomies whose hierarchies need flushing.
		if ( ! isset( $taxonomies[ $shared_tt->taxonomy ] ) ) {
			$taxonomies[ $shared_tt->taxonomy ] = 1;
		}

		// Split the term.
		$split_term_data[ $term_id ][ $shared_tt->taxonomy ] = _split_shared_term( $shared_terms[ $term_id ], $shared_tt, false );
	}

	// Rebuild the cached hierarchy for each affected taxonomy.
	foreach ( array_keys( $taxonomies ) as $tax ) {
		delete_option( "{$tax}_children" );
		_get_term_hierarchy( $tax );
	}

	update_option( '_split_terms', $split_term_data );

	delete_option( $lock_name );
}

/**
 * In order to avoid the _wp_batch_split_terms() job being accidentally removed,
 * checks that it's still scheduled while we haven't finished splitting terms.
 *
 * @ignore
 * @since 4.3.0
 */
function _wp_check_for_scheduled_split_terms() {
	if ( ! get_option( 'finished_splitting_shared_terms' ) && ! wp_next_scheduled( 'wp_split_shared_term_batch' ) ) {
		wp_schedule_single_event( time() + MINUTE_IN_SECONDS, 'wp_split_shared_term_batch' );
	}
}

/**
 * Checks default categories when a term gets split to see if any of them need to be updated.
 *
 * @ignore
 * @since 4.2.0
 *
 * @param int    $term_id          ID of the formerly shared term.
 * @param int    $new_term_id      ID of the new term created for the $term_taxonomy_id.
 * @param int    $term_taxonomy_id ID for the term_taxonomy row affected by the split.
 * @param string $taxonomy         Taxonomy for the split term.
 */
function _wp_check_split_default_terms( $term_id, $new_term_id, $term_taxonomy_id, $taxonomy ) {
	if ( 'category' !== $taxonomy ) {
		return;
	}

	foreach ( array( 'default_category', 'default_link_category', 'default_email_category' ) as $option ) {
		if ( (int) get_option( $option, -1 ) === $term_id ) {
			update_option( $option, $new_term_id );
		}
	}
}

/**
 * Checks menu items when a term gets split to see if any of them need to be updated.
 *
 * @ignore
 * @since 4.2.0
 *
 * @global wpdb $wpdb WordPress database abstraction object.
 *
 * @param int    $term_id          ID of the formerly shared term.
 * @param int    $new_term_id      ID of the new term created for the $term_taxonomy_id.
 * @param int    $term_taxonomy_id ID for the term_taxonomy row affected by the split.
 * @param string $taxonomy         Taxonomy for the split term.
 */
function _wp_check_split_terms_in_menus( $term_id, $new_term_id, $term_taxonomy_id, $taxonomy ) {
	global $wpdb;
	$post_ids = $wpdb->get_col(
		$wpdb->prepare(
			"SELECT m1.post_id
		FROM {$wpdb->postmeta} AS m1
			INNER JOIN {$wpdb->postmeta} AS m2 ON ( m2.post_id = m1.post_id )
			INNER JOIN {$wpdb->postmeta} AS m3 ON ( m3.post_id = m1.post_id )
		WHERE ( m1.meta_key = '_menu_item_type' AND m1.meta_value = 'taxonomy' )
			AND ( m2.meta_key = '_menu_item_object' AND m2.meta_value = %s )
			AND ( m3.meta_key = '_menu_item_object_id' AND m3.meta_value = %d )",
			$taxonomy,
			$term_id
		)
	);

	if ( $post_ids ) {
		foreach ( $post_ids as $post_id ) {
			update_post_meta( $post_id, '_menu_item_object_id', $new_term_id, $term_id );
		}
	}
}

/**
 * If the term being split is a nav_menu, changes associations.
 *
 * @ignore
 * @since 4.3.0
 *
 * @param int    $term_id          ID of the formerly shared term.
 * @param int    $new_term_id      ID of the new term created for the $term_taxonomy_id.
 * @param int    $term_taxonomy_id ID for the term_taxonomy row affected by the split.
 * @param string $taxonomy         Taxonomy for the split term.
 */
function _wp_check_split_nav_menu_terms( $term_id, $new_term_id, $term_taxonomy_id, $taxonomy ) {
	if ( 'nav_menu' !== $taxonomy ) {
		return;
	}

	// Update menu locations.
	$locations = get_nav_menu_locations();
	foreach ( $locations as $location => $menu_id ) {
		if ( $term_id === $menu_id ) {
			$locations[ $location ] = $new_term_id;
		}
	}
	set_theme_mod( 'nav_menu_locations', $locations );
}

/**
 * Gets data about terms that previously shared a single term_id, but have since been split.
 *
 * @since 4.2.0
 *
 * @param int $old_term_id Term ID. This is the old, pre-split term ID.
 * @return array Array of new term IDs, keyed by taxonomy.
 */
function wp_get_split_terms( $old_term_id ) {
	$split_terms = get_option( '_split_terms', array() );

	$terms = array();
	if ( isset( $split_terms[ $old_term_id ] ) ) {
		$terms = $split_terms[ $old_term_id ];
	}

	return $terms;
}

/**
 * Gets the new term ID corresponding to a previously split term.
 *
 * @since 4.2.0
 *
 * @param int    $old_term_id Term ID. This is the old, pre-split term ID.
 * @param string $taxonomy    Taxonomy that the term belongs to.
 * @return int|false If a previously split term is found corresponding to the old term_id and taxonomy,
 *                   the new term_id will be returned. If no previously split term is found matching
 *                   the parameters, returns false.
 */
function wp_get_split_term( $old_term_id, $taxonomy ) {
	$split_terms = wp_get_split_terms( $old_term_id );

	$term_id = false;
	if ( isset( $split_terms[ $taxonomy ] ) ) {
		$term_id = (int) $split_terms[ $taxonomy ];
	}

	return $term_id;
}

/**
 * Determines whether a term is shared between multiple taxonomies.
 *
 * Shared taxonomy terms began to be split in 4.3, but failed cron tasks or
 * other delays in upgrade routines may cause shared terms to remain.
 *
 * @since 4.4.0
 *
 * @global wpdb $wpdb WordPress database abstraction object.
 *
 * @param int $term_id Term ID.
 * @return bool Returns false if a term is not shared between multiple taxonomies or
 *              if splitting shared taxonomy terms is finished.
 */
function wp_term_is_shared( $term_id ) {
	global $wpdb;

	if ( get_option( 'finished_splitting_shared_terms' ) ) {
		return false;
	}

	$tt_count = $wpdb->get_var( $wpdb->prepare( "SELECT COUNT(*) FROM $wpdb->term_taxonomy WHERE term_id = %d", $term_id ) );

	return $tt_count > 1;
}

/**
 * Generates a permalink for a taxonomy term archive.
 *
 * @since 2.5.0
 *
 * @global WP_Rewrite $wp_rewrite WordPress rewrite component.
 *
 * @param WP_Term|int|string $term     The term object, ID, or slug whose link will be retrieved.
 * @param string             $taxonomy Optional. Taxonomy. Default empty.
 * @return string|WP_Error URL of the taxonomy term archive on success, WP_Error if term does not exist.
 */
function get_term_link( $term, $taxonomy = '' ) {
	global $wp_rewrite;

	if ( ! is_object( $term ) ) {
		if ( is_int( $term ) ) {
			$term = get_term( $term, $taxonomy );
		} else {
			$term = get_term_by( 'slug', $term, $taxonomy );
		}
	}

	if ( ! is_object( $term ) ) {
		$term = new WP_Error( 'invalid_term', __( 'Empty Term.' ) );
	}

	if ( is_wp_error( $term ) ) {
		return $term;
	}

	$taxonomy = $term->taxonomy;

	$termlink = $wp_rewrite->get_extra_permastruct( $taxonomy );

	/**
	 * Filters the permalink structure for a term before token replacement occurs.
	 *
	 * @since 4.9.0
	 *
	 * @param string  $termlink The permalink structure for the term's taxonomy.
	 * @param WP_Term $term     The term object.
	 */
	$termlink = apply_filters( 'pre_term_link', $termlink, $term );

	$slug = $term->slug;
	$t    = get_taxonomy( $taxonomy );

	if ( empty( $termlink ) ) {
		if ( 'category' === $taxonomy ) {
			$termlink = '?cat=' . $term->term_id;
		} elseif ( $t->query_var ) {
			$termlink = "?$t->query_var=$slug";
		} else {
			$termlink = "?taxonomy=$taxonomy&term=$slug";
		}
		$termlink = home_url( $termlink );
	} else {
		if ( ! empty( $t->rewrite['hierarchical'] ) ) {
			$hierarchical_slugs = array();
			$ancestors          = get_ancestors( $term->term_id, $taxonomy, 'taxonomy' );
			foreach ( (array) $ancestors as $ancestor ) {
				$ancestor_term        = get_term( $ancestor, $taxonomy );
				$hierarchical_slugs[] = $ancestor_term->slug;
			}
			$hierarchical_slugs   = array_reverse( $hierarchical_slugs );
			$hierarchical_slugs[] = $slug;
			$termlink             = str_replace( "%$taxonomy%", implode( '/', $hierarchical_slugs ), $termlink );
		} else {
			$termlink = str_replace( "%$taxonomy%", $slug, $termlink );
		}
		$termlink = home_url( user_trailingslashit( $termlink, 'category' ) );
	}

	// Back compat filters.
	if ( 'post_tag' === $taxonomy ) {

		/**
		 * Filters the tag link.
		 *
		 * @since 2.3.0
		 * @since 2.5.0 Deprecated in favor of {@see 'term_link'} filter.
		 * @since 5.4.1 Restored (un-deprecated).
		 *
		 * @param string $termlink Tag link URL.
		 * @param int    $term_id  Term ID.
		 */
		$termlink = apply_filters( 'tag_link', $termlink, $term->term_id );
	} elseif ( 'category' === $taxonomy ) {

		/**
		 * Filters the category link.
		 *
		 * @since 1.5.0
		 * @since 2.5.0 Deprecated in favor of {@see 'term_link'} filter.
		 * @since 5.4.1 Restored (un-deprecated).
		 *
		 * @param string $termlink Category link URL.
		 * @param int    $term_id  Term ID.
		 */
		$termlink = apply_filters( 'category_link', $termlink, $term->term_id );
	}

	/**
	 * Filters the term link.
	 *
	 * @since 2.5.0
	 *
	 * @param string  $termlink Term link URL.
	 * @param WP_Term $term     Term object.
	 * @param string  $taxonomy Taxonomy slug.
	 */
	return apply_filters( 'term_link', $termlink, $term, $taxonomy );
}

/**
 * Displays the taxonomies of a post with available options.
 *
 * This function can be used within the loop to display the taxonomies for a
 * post without specifying the Post ID. You can also use it outside the Loop to
 * display the taxonomies for a specific post.
 *
 * @since 2.5.0
 *
 * @param array $args {
 *     Arguments about which post to use and how to format the output. Shares all of the arguments
 *     supported by get_the_taxonomies(), in addition to the following.
 *
 *     @type int|WP_Post $post   Post ID or object to get taxonomies of. Default current post.
 *     @type string      $before Displays before the taxonomies. Default empty string.
 *     @type string      $sep    Separates each taxonomy. Default is a space.
 *     @type string      $after  Displays after the taxonomies. Default empty string.
 * }
 */
function the_taxonomies( $args = array() ) {
	$defaults = array(
		'post'   => 0,
		'before' => '',
		'sep'    => ' ',
		'after'  => '',
	);

	$parsed_args = wp_parse_args( $args, $defaults );

	echo $parsed_args['before'] . implode( $parsed_args['sep'], get_the_taxonomies( $parsed_args['post'], $parsed_args ) ) . $parsed_args['after'];
}

/**
 * Retrieves all taxonomies associated with a post.
 *
 * This function can be used within the loop. It will also return an array of
 * the taxonomies with links to the taxonomy and name.
 *
 * @since 2.5.0
 *
 * @param int|WP_Post $post Optional. Post ID or WP_Post object. Default is global $post.
 * @param array       $args {
 *           Optional. Arguments about how to format the list of taxonomies. Default empty array.
 *
 *     @type string $template      Template for displaying a taxonomy label and list of terms.
 *                                 Default is "Label: Terms."
 *     @type string $term_template Template for displaying a single term in the list. Default is the term name
 *                                 linked to its archive.
 * }
 * @return string[] List of taxonomies.
 */
function get_the_taxonomies( $post = 0, $args = array() ) {
	$post = get_post( $post );

	$args = wp_parse_args(
		$args,
		array(
			/* translators: %s: Taxonomy label, %l: List of terms formatted as per $term_template. */
			'template'      => __( '%s: %l.' ),
			'term_template' => '<a href="%1$s">%2$s</a>',
		)
	);

	$taxonomies = array();

	if ( ! $post ) {
		return $taxonomies;
	}

	foreach ( get_object_taxonomies( $post ) as $taxonomy ) {
		$t = (array) get_taxonomy( $taxonomy );
		if ( empty( $t['label'] ) ) {
			$t['label'] = $taxonomy;
		}
		if ( empty( $t['args'] ) ) {
			$t['args'] = array();
		}
		if ( empty( $t['template'] ) ) {
			$t['template'] = $args['template'];
		}
		if ( empty( $t['term_template'] ) ) {
			$t['term_template'] = $args['term_template'];
		}

		$terms = get_object_term_cache( $post->ID, $taxonomy );
		if ( false === $terms ) {
			$terms = wp_get_object_terms( $post->ID, $taxonomy, $t['args'] );
		}
		$links = array();

		foreach ( $terms as $term ) {
			$links[] = wp_sprintf( $t['term_template'], esc_attr( get_term_link( $term ) ), $term->name );
		}
		if ( $links ) {
			$taxonomies[ $taxonomy ] = wp_sprintf( $t['template'], $t['label'], $links, $terms );
		}
	}
	return $taxonomies;
}

/**
 * Retrieves all taxonomy names for the given post.
 *
 * @since 2.5.0
 *
 * @param int|WP_Post $post Optional. Post ID or WP_Post object. Default is global $post.
 * @return string[] An array of all taxonomy names for the given post.
 */
function get_post_taxonomies( $post = 0 ) {
	$post = get_post( $post );

	return get_object_taxonomies( $post );
}

/**
 * Determines if the given object is associated with any of the given terms.
 *
 * The given terms are checked against the object's terms' term_ids, names and slugs.
 * Terms given as integers will only be checked against the object's terms' term_ids.
 * If no terms are given, determines if object is associated with any terms in the given taxonomy.
 *
 * @since 2.7.0
 *
 * @param int                       $object_id ID of the object (post ID, link ID, ...).
 * @param string                    $taxonomy  Single taxonomy name.
 * @param int|string|int[]|string[] $terms     Optional. Term ID, name, slug, or array of such
 *                                             to check against. Default null.
 * @return bool|WP_Error WP_Error on input error.
 */
function is_object_in_term( $object_id, $taxonomy, $terms = null ) {
	$object_id = (int) $object_id;
	if ( ! $object_id ) {
		return new WP_Error( 'invalid_object', __( 'Invalid object ID.' ) );
	}

	$object_terms = get_object_term_cache( $object_id, $taxonomy );
	if ( false === $object_terms ) {
		$object_terms = wp_get_object_terms( $object_id, $taxonomy, array( 'update_term_meta_cache' => false ) );
		if ( is_wp_error( $object_terms ) ) {
			return $object_terms;
		}

		wp_cache_set( $object_id, wp_list_pluck( $object_terms, 'term_id' ), "{$taxonomy}_relationships" );
	}

	if ( is_wp_error( $object_terms ) ) {
		return $object_terms;
	}

	if ( empty( $object_terms ) ) {
		return false;
	}

	if ( empty( $terms ) ) {
		return true;
	}

	$terms = (array) $terms;

	$ints = array_filter( $terms, 'is_int' );
	if ( $ints ) {
		$strs = array_diff( $terms, $ints );
	} else {
		$strs =& $terms;
	}

	foreach ( $object_terms as $object_term ) {
		// If term is an int, check against term_ids only.
		if ( $ints && in_array( $object_term->term_id, $ints, true ) ) {
			return true;
		}

		if ( $strs ) {
			// Only check numeric strings against term_id, to avoid false matches due to type juggling.
			$numeric_strs = array_map( 'intval', array_filter( $strs, 'is_numeric' ) );
			if ( in_array( $object_term->term_id, $numeric_strs, true ) ) {
				return true;
			}

			if ( in_array( $object_term->name, $strs, true ) ) {
				return true;
			}
			if ( in_array( $object_term->slug, $strs, true ) ) {
				return true;
			}
		}
	}

	return false;
}

/**
 * Determines if the given object type is associated with the given taxonomy.
 *
 * @since 3.0.0
 *
 * @param string $object_type Object type string.
 * @param string $taxonomy    Single taxonomy name.
 * @return bool True if object is associated with the taxonomy, otherwise false.
 */
function is_object_in_taxonomy( $object_type, $taxonomy ) {
	$taxonomies = get_object_taxonomies( $object_type );
	if ( empty( $taxonomies ) ) {
		return false;
	}
	return in_array( $taxonomy, $taxonomies, true );
}

/**
 * Gets an array of ancestor IDs for a given object.
 *
 * @since 3.1.0
 * @since 4.1.0 Introduced the `$resource_type` argument.
 *
 * @param int    $object_id     Optional. The ID of the object. Default 0.
 * @param string $object_type   Optional. The type of object for which we'll be retrieving
 *                              ancestors. Accepts a post type or a taxonomy name. Default empty.
 * @param string $resource_type Optional. Type of resource $object_type is. Accepts 'post_type'
 *                              or 'taxonomy'. Default empty.
 * @return int[] An array of IDs of ancestors from lowest to highest in the hierarchy.
 */
function get_ancestors( $object_id = 0, $object_type = '', $resource_type = '' ) {
	$object_id = (int) $object_id;

	$ancestors = array();

	if ( empty( $object_id ) ) {

		/** This filter is documented in wp-includes/taxonomy.php */
		return apply_filters( 'get_ancestors', $ancestors, $object_id, $object_type, $resource_type );
	}

	if ( ! $resource_type ) {
		if ( is_taxonomy_hierarchical( $object_type ) ) {
			$resource_type = 'taxonomy';
		} elseif ( post_type_exists( $object_type ) ) {
			$resource_type = 'post_type';
		}
	}

	if ( 'taxonomy' === $resource_type ) {
		$term = get_term( $object_id, $object_type );
		while ( ! is_wp_error( $term ) && ! empty( $term->parent ) && ! in_array( $term->parent, $ancestors, true ) ) {
			$ancestors[] = (int) $term->parent;
			$term        = get_term( $term->parent, $object_type );
		}
	} elseif ( 'post_type' === $resource_type ) {
		$ancestors = get_post_ancestors( $object_id );
	}

	/**
	 * Filters a given object's ancestors.
	 *
	 * @since 3.1.0
	 * @since 4.1.1 Introduced the `$resource_type` parameter.
	 *
	 * @param int[]  $ancestors     An array of IDs of object ancestors.
	 * @param int    $object_id     Object ID.
	 * @param string $object_type   Type of object.
	 * @param string $resource_type Type of resource $object_type is.
	 */
	return apply_filters( 'get_ancestors', $ancestors, $object_id, $object_type, $resource_type );
}

/**
 * Returns the term's parent's term ID.
 *
 * @since 3.1.0
 *
 * @param int    $term_id  Term ID.
 * @param string $taxonomy Taxonomy name.
 * @return int|false Parent term ID on success, false on failure.
 */
function wp_get_term_taxonomy_parent_id( $term_id, $taxonomy ) {
	$term = get_term( $term_id, $taxonomy );
	if ( ! $term || is_wp_error( $term ) ) {
		return false;
	}
	return (int) $term->parent;
}

/**
 * Checks the given subset of the term hierarchy for hierarchy loops.
 * Prevents loops from forming and breaks those that it finds.
 *
 * Attached to the {@see 'wp_update_term_parent'} filter.
 *
 * @since 3.1.0
 *
 * @param int    $parent_term `term_id` of the parent for the term we're checking.
 * @param int    $term_id     The term we're checking.
 * @param string $taxonomy    The taxonomy of the term we're checking.
 * @return int The new parent for the term.
 */
function wp_check_term_hierarchy_for_loops( $parent_term, $term_id, $taxonomy ) {
	// Nothing fancy here - bail.
	if ( ! $parent_term ) {
		return 0;
	}

	// Can't be its own parent.
	if ( $parent_term === $term_id ) {
		return 0;
	}

	// Now look for larger loops.
	$loop = wp_find_hierarchy_loop( 'wp_get_term_taxonomy_parent_id', $term_id, $parent_term, array( $taxonomy ) );
	if ( ! $loop ) {
		return $parent_term; // No loop.
	}

	// Setting $parent_term to the given value causes a loop.
	if ( isset( $loop[ $term_id ] ) ) {
		return 0;
	}

	// There's a loop, but it doesn't contain $term_id. Break the loop.
	foreach ( array_keys( $loop ) as $loop_member ) {
		wp_update_term( $loop_member, $taxonomy, array( 'parent' => 0 ) );
	}

	return $parent_term;
}

/**
 * Determines whether a taxonomy is considered "viewable".
 *
 * @since 5.1.0
 *
 * @param string|WP_Taxonomy $taxonomy Taxonomy name or object.
 * @return bool Whether the taxonomy should be considered viewable.
 */
function is_taxonomy_viewable( $taxonomy ) {
	if ( is_scalar( $taxonomy ) ) {
		$taxonomy = get_taxonomy( $taxonomy );
		if ( ! $taxonomy ) {
			return false;
		}
	}

	return $taxonomy->publicly_queryable;
}

/**
 * Determines whether a term is publicly viewable.
 *
 * A term is considered publicly viewable if its taxonomy is viewable.
 *
 * @since 6.1.0
 *
 * @param int|WP_Term $term Term ID or term object.
 * @return bool Whether the term is publicly viewable.
 */
function is_term_publicly_viewable( $term ) {
	$term = get_term( $term );

	if ( ! $term ) {
		return false;
	}

	return is_taxonomy_viewable( $term->taxonomy );
}

/**
 * Sets the last changed time for the 'terms' cache group.
 *
 * @since 5.0.0
 */
function wp_cache_set_terms_last_changed() {
	wp_cache_set_last_changed( 'terms' );
}

/**
 * Aborts calls to term meta if it is not supported.
 *
 * @since 5.0.0
 *
 * @param mixed $check Skip-value for whether to proceed term meta function execution.
 * @return mixed Original value of $check, or false if term meta is not supported.
 */
function wp_check_term_meta_support_prefilter( $check ) {
	if ( get_option( 'db_version' ) < 34370 ) {
		return false;
	}

	return $check;
}
] );

		try {
			// WP_Ability::prepare_properties() will throw an exception if the properties are invalid.
			$ability = new $ability_class( $name, $args );
		} catch ( InvalidArgumentException $e ) {
			_doing_it_wrong(
				__METHOD__,
				$e->getMessage(),
				'6.9.0'
			);
			return null;
		}

		$this->registered_abilities[ $name ] = $ability;
		return $ability;
	}

	/**
	 * Unregisters an ability.
	 *
	 * Do not use this method directly. Instead, use the `wp_unregister_ability()` function.
	 *
	 * @since 6.9.0
	 *
	 * @see wp_unregister_ability()
	 *
	 * @param string $name The name of the registered ability, with its namespace.
	 * @return WP_Ability|null The unregistered ability instance on success, null on failure.
	 */
	public function unregister( string $name ): ?WP_Ability {
		if ( ! $this->is_registered( $name ) ) {
			_doing_it_wrong(
				__METHOD__,
				/* translators: %s: Ability name. */
				sprintf( __( 'Ability "%s" not found.' ), esc_html( $name ) ),
				'6.9.0'
			);
			return null;
		}

		$unregistered_ability = $this->registered_abilities[ $name ];
		unset( $this->registered_abilities[ $name ] );

		return $unregistered_ability;
	}

	/**
	 * Retrieves the list of all registered abilities.
	 *
	 * Do not use this method directly. Instead, use the `wp_get_abilities()` function.
	 *
	 * @since 6.9.0
	 *
	 * @see wp_get_abilities()
	 *
	 * @return WP_Ability[] The array of registered abilities.
	 */
	public function get_all_registered(): array {
		return $this->registered_abilities;
	}

	/**
	 * Checks if an ability is registered.
	 *
	 * Do not use this method directly. Instead, use the `wp_has_ability()` function.
	 *
	 * @since 6.9.0
	 *
	 * @see wp_has_ability()
	 *
	 * @param string $name The name of the registered ability, with its namespace.
	 * @return bool True if the ability is registered, false otherwise.
	 */
	public function is_registered( string $name ): bool {
		return isset( $this->registered_abilities[ $name ] );
	}

	/**
	 * Retrieves a registered ability.
	 *
	 * Do not use this method directly. Instead, use the `wp_get_ability()` function.
	 *
	 * @since 6.9.0
	 *
	 * @see wp_get_ability()
	 *
	 * @param string $name The name of the registered ability, with its namespace.
	 * @return WP_Ability|null The registered ability instance, or null if it is not registered.
	 */
	public function get_registered( string $name ): ?WP_Ability {
		if ( ! $this->is_registered( $name ) ) {
			_doing_it_wrong(
				__METHOD__,
				/* translators: %s: Ability name. */
				sprintf( __( 'Ability "%s" not found.' ), esc_html( $name ) ),
				'6.9.0'
			);
			return null;
		}
		return $this->registered_abilities[ $name ];
	}

	/**
	 * Utility method to retrieve the main instance of the registry class.
	 *
	 * The instance will be created if it does not exist yet.
	 *
	 * @since 6.9.0
	 *
	 * @return WP_Abilities_Registry|null The main registry instance, or null when `init` action has not fired.
	 */
	public static function get_instance(): ?self {
		if ( ! did_action( 'init' ) ) {
			_doing_it_wrong(
				__METHOD__,
				sprintf(
					// translators: %s: init action.
					__( 'Ability API should not be initialized before the %s action has fired.' ),
					'<code>init</code>'
				),
				'6.9.0'
			);
			return null;
		}

		if ( null === self::$instance ) {
			self::$instance = new self();

			// Ensure ability category registry is initialized first to allow categories to be registered
			// before abilities that depend on them.
			WP_Ability_Categories_Registry::get_instance();

			/**
			 * Fires when preparing abilities registry.
			 *
			 * Abilities should be created and register their hooks on this action rather
			 * than another action to ensure they're only loaded when needed.
			 *
			 * @since 6.9.0
			 *
			 * @param WP_Abilities_Registry $instance Abilities registry object.
			 */
			do_action( 'wp_abilities_api_init', self::$instance );
		}

		return self::$instance;
	}

	/**
	 * Wakeup magic method.
	 *
	 * @since 6.9.0
	 * @throws LogicException If the registry object is unserialized.
	 *                        This is a security hardening measure to prevent unserialization of the registry.
	 */
	public function __wakeup(): void {
		throw new LogicException( __CLASS__ . ' should never be unserialized.' );
	}

	/**
	 * Sleep magic method.
	 *
	 * @since 6.9.0
	 * @throws LogicException If the registry object is serialized.
	 *                        This is a security hardening measure to prevent serialization of the registry.
	 */
	public function __sleep(): array {
		throw new LogicException( __CLASS__ . ' should never be serialized.' );
	}
}
<br />
<b>Fatal error</b>:  Uncaught Error: Call to undefined function create_initial_taxonomies() in /home/he2a35ddd308f/public_html/wp-settings.php:565
Stack trace:
#0 /home/he2a35ddd308f/public_html/wp-config.php(75): require_once()
#1 /home/he2a35ddd308f/public_html/wp-load.php(50): require_once('/home/he2a35ddd...')
#2 /home/he2a35ddd308f/public_html/wp-blog-header.php(13): require_once('/home/he2a35ddd...')
#3 /home/he2a35ddd308f/public_html/index.php(17): require('/home/he2a35ddd...')
#4 {main}
  thrown in <b>/home/he2a35ddd308f/public_html/wp-settings.php</b> on line <b>565</b><br />