<?php
/**
* Canonical API to handle WordPress Redirecting
*
* Based on "Permalink Redirect" from Scott Yang and "Enforce www. Preference"
* by Mark Jaquith
*
* @package WordPress
* @since 2.3.0
*/

/**
* Redirects incoming links to the proper URL based on the site url.
*
* Search engines consider www.somedomain.com and somedomain.com to be two
* different URLs when they both go to the same location. This SEO enhancement
* prevents penalty for duplicate content by redirecting all incoming links to
* one or the other.
*
* Prevents redirection for feeds, trackbacks, searches, and
* admin URLs. Does not redirect on non-pretty-permalink-supporting IIS 7+,
* page/post previews, WP admin, Trackbacks, robots.txt, favicon.ico, searches,
* or on POST requests.
*
* Will also attempt to find the correct link when a user enters a URL that does
* not exist based on exact WordPress query. Will instead try to parse the URL
* or query in an attempt to figure the correct page to go to.
*
* @since 2.3.0
*
* @global WP_Rewrite $wp_rewrite WordPress rewrite component.
* @global bool $is_IIS
* @global WP_Query $wp_query WordPress Query object.
* @global wpdb $wpdb WordPress database abstraction object.
* @global WP $wp Current WordPress environment instance.
*
* @param string $requested_url Optional. The URL that was requested, used to
* figure if redirect is needed.
* @param bool $do_redirect Optional. Redirect to the new URL.
* @return string|void The string of the URL, if redirect needed.
*/
function redirect_canonical( $requested_url = null, $do_redirect = true ) {
global $wp_rewrite, $is_IIS, $wp_query, $wpdb, $wp;

if ( isset( $_SERVER['REQUEST_METHOD'] ) && ! in_array( strtoupper( $_SERVER['REQUEST_METHOD'] ), array( 'GET', 'HEAD' ), true ) ) {
return;
}

/*
* If we're not in wp-admin and the post has been published and preview nonce
* is non-existent or invalid then no need for preview in query.
*/
if ( is_preview() && get_query_var( 'p' ) && 'publish' === get_post_status( get_query_var( 'p' ) ) ) {
if ( ! isset( $_GET['preview_id'] )
|| ! isset( $_GET['preview_nonce'] )
|| ! wp_verify_nonce( $_GET['preview_nonce'], 'post_preview_' . (int) $_GET['preview_id'] )
) {
$wp_query->is_preview = false;
}
}

if ( is_admin() || is_search() || is_preview() || is_trackback() || is_favicon()
|| ( $is_IIS && ! iis7_supports_permalinks() )
) {
return;
}

if ( ! $requested_url && isset( $_SERVER['HTTP_HOST'] ) ) {
// Build the URL in the address bar.
$requested_url = is_ssl() ? 'https://' : 'http://';
$requested_url .= $_SERVER['HTTP_HOST'];
$requested_url .= $_SERVER['REQUEST_URI'];
}

$original = parse_url( $requested_url );
if ( false === $original ) {
return;
}

$redirect = $original;
$redirect_url = false;
$redirect_obj = false;

// Notice fixing.
if ( ! isset( $redirect['path'] ) ) {
$redirect['path'] = '';
}
if ( ! isset( $redirect['query'] ) ) {
$redirect['query'] = '';
}

/*
* If the original URL ended with non-breaking spaces, they were almost
* certainly inserted by accident. Let's remove them, so the reader doesn't
* see a 404 error with no obvious cause.
*/
$redirect['path'] = preg_replace( '|(%C2%A0)+$|i', '', $redirect['path'] );

// It's not a preview, so remove it from URL.
if ( get_query_var( 'preview' ) ) {
$redirect['query'] = remove_query_arg( 'preview', $redirect['query'] );
}

$post_id = get_query_var( 'p' );

if ( is_feed() && $post_id ) {
$redirect_url = get_post_comments_feed_link( $post_id, get_query_var( 'feed' ) );
$redirect_obj = get_post( $post_id );

if ( $redirect_url ) {
$redirect['query'] = _remove_qs_args_if_not_in_url(
$redirect['query'],
array( 'p', 'page_id', 'attachment_id', 'pagename', 'name', 'post_type', 'feed' ),
$redirect_url
);

$redirect['path'] = parse_url( $redirect_url, PHP_URL_PATH );
}
}

if ( is_singular() && $wp_query->post_count < 1 && $post_id ) {

$vars = $wpdb->get_results( $wpdb->prepare( "SELECT post_type, post_parent FROM $wpdb->posts WHERE ID = %d", $post_id ) );

if ( ! empty( $vars[0] ) ) {
$vars = $vars[0];

if ( 'revision' === $vars->post_type && $vars->post_parent > 0 ) {
$post_id = $vars->post_parent;
}

$redirect_url = get_permalink( $post_id );
$redirect_obj = get_post( $post_id );

if ( $redirect_url ) {
$redirect['query'] = _remove_qs_args_if_not_in_url(
$redirect['query'],
array( 'p', 'page_id', 'attachment_id', 'pagename', 'name', 'post_type' ),
$redirect_url
);
}
}
}

// These tests give us a WP-generated permalink.
if ( is_404() ) {

// Redirect ?page_id, ?p=, ?attachment_id= to their respective URLs.
$post_id = max( get_query_var( 'p' ), get_query_var( 'page_id' ), get_query_var( 'attachment_id' ) );

$redirect_post = $post_id ? get_post( $post_id ) : false;

if ( $redirect_post ) {
$post_type_obj = get_post_type_object( $redirect_post->post_type );

if ( $post_type_obj && $post_type_obj->public && 'auto-draft' !== $redirect_post->post_status ) {
$redirect_url = get_permalink( $redirect_post );
$redirect_obj = get_post( $redirect_post );

$redirect['query'] = _remove_qs_args_if_not_in_url(
$redirect['query'],
array( 'p', 'page_id', 'attachment_id', 'pagename', 'name', 'post_type' ),
$redirect_url
);
}
}

$year = get_query_var( 'year' );
$month = get_query_var( 'monthnum' );
$day = get_query_var( 'day' );

if ( $year && $month && $day ) {
$date = sprintf( '%04d-%02d-%02d', $year, $month, $day );

if ( ! wp_checkdate( $month, $day, $year, $date ) ) {
$redirect_url = get_month_link( $year, $month );

$redirect['query'] = _remove_qs_args_if_not_in_url(
$redirect['query'],
array( 'year', 'monthnum', 'day' ),
$redirect_url
);
}
} elseif ( $year && $month && $month > 12 ) {
$redirect_url = get_year_link( $year );

$redirect['query'] = _remove_qs_args_if_not_in_url(
$redirect['query'],
array( 'year', 'monthnum' ),
$redirect_url
);
}

// Strip off non-existing <!--nextpage--> links from single posts or pages.
if ( get_query_var( 'page' ) ) {
$post_id = 0;

if ( $wp_query->queried_object instanceof WP_Post ) {
$post_id = $wp_query->queried_object->ID;
} elseif ( $wp_query->post ) {
$post_id = $wp_query->post->ID;
}

if ( $post_id ) {
$redirect_url = get_permalink( $post_id );
$redirect_obj = get_post( $post_id );

$redirect['path'] = rtrim( $redirect['path'], (int) get_query_var( 'page' ) . '/' );
$redirect['query'] = remove_query_arg( 'page', $redirect['query'] );
}
}

if ( ! $redirect_url ) {
$redirect_url = redirect_guess_404_permalink();

if ( $redirect_url ) {
$redirect['query'] = _remove_qs_args_if_not_in_url(
$redirect['query'],
array( 'page', 'feed', 'p', 'page_id', 'attachment_id', 'pagename', 'name', 'post_type' ),
$redirect_url
);
}
}
} elseif ( is_object( $wp_rewrite ) && $wp_rewrite->using_permalinks() ) {

// Rewriting of old ?p=X, ?m=2004, ?m=200401, ?m=20040101.
if ( is_attachment()
&& ! array_diff( array_keys( $wp->query_vars ), array( 'attachment', 'attachment_id' ) )
&& ! $redirect_url
) {
if ( ! empty( $_GET['attachment_id'] ) ) {
$redirect_url = get_attachment_link( get_query_var( 'attachment_id' ) );
$redirect_obj = get_post( get_query_var( 'attachment_id' ) );

if ( $redirect_url ) {
$redirect['query'] = remove_query_arg( 'attachment_id', $redirect['query'] );
}
} else {
$redirect_url = get_attachment_link();
$redirect_obj = get_post();
}
} elseif ( is_single() && ! empty( $_GET['p'] ) && ! $redirect_url ) {
$redirect_url = get_permalink( get_query_var( 'p' ) );
$redirect_obj = get_post( get_query_var( 'p' ) );

if ( $redirect_url ) {
$redirect['query'] = remove_query_arg( array( 'p', 'post_type' ), $redirect['query'] );
}
} elseif ( is_single() && ! empty( $_GET['name'] ) && ! $redirect_url ) {
$redirect_url = get_permalink( $wp_query->get_queried_object_id() );
$redirect_obj = get_post( $wp_query->get_queried_object_id() );

if ( $redirect_url ) {
$redirect['query'] = remove_query_arg( 'name', $redirect['query'] );
}
} elseif ( is_page() && ! empty( $_GET['page_id'] ) && ! $redirect_url ) {
$redirect_url = get_permalink( get_query_var( 'page_id' ) );
$redirect_obj = get_post( get_query_var( 'page_id' ) );

if ( $redirect_url ) {
$redirect['query'] = remove_query_arg( 'page_id', $redirect['query'] );
}
} elseif ( is_page() && ! is_feed() && ! $redirect_url
&& 'page' === get_option( 'show_on_front' ) && get_queried_object_id() === (int) get_option( 'page_on_front' )
) {
$redirect_url = home_url( '/' );
} elseif ( is_home() && ! empty( $_GET['page_id'] ) && ! $redirect_url
&& 'page' === get_option( 'show_on_front' ) && get_query_var( 'page_id' ) === (int) get_option( 'page_for_posts' )
) {
$redirect_url = get_permalink( get_option( 'page_for_posts' ) );
$redirect_obj = get_post( get_option( 'page_for_posts' ) );

if ( $redirect_url ) {
$redirect['query'] = remove_query_arg( 'page_id', $redirect['query'] );
}
} elseif ( ! empty( $_GET['m'] ) && ( is_year() || is_month() || is_day() ) ) {
$m = get_query_var( 'm' );

switch ( strlen( $m ) ) {
case 4: // Yearly.
$redirect_url = get_year_link( $m );
break;
case 6: // Monthly.
$redirect_url = get_month_link( substr( $m, 0, 4 ), substr( $m, 4, 2 ) );
break;
case 8: // Daily.
$redirect_url = get_day_link( substr( $m, 0, 4 ), substr( $m, 4, 2 ), substr( $m, 6, 2 ) );
break;
}

if ( $redirect_url ) {
$redirect['query'] = remove_query_arg( 'm', $redirect['query'] );
}
// Now moving on to non ?m=X year/month/day links.
} elseif ( is_date() ) {
$year = get_query_var( 'year' );
$month = get_query_var( 'monthnum' );
$day = get_query_var( 'day' );

if ( is_day() && $year && $month && ! empty( $_GET['day'] ) ) {
$redirect_url = get_day_link( $year, $month, $day );

if ( $redirect_url ) {
$redirect['query'] = remove_query_arg( array( 'year', 'monthnum', 'day' ), $redirect['query'] );
}
} elseif ( is_month() && $year && ! empty( $_GET['monthnum'] ) ) {
$redirect_url = get_month_link( $year, $month );

if ( $redirect_url ) {
$redirect['query'] = remove_query_arg( array( 'year', 'monthnum' ), $redirect['query'] );
}
} elseif ( is_year() && ! empty( $_GET['year'] ) ) {
$redirect_url = get_year_link( $year );

if ( $redirect_url ) {
$redirect['query'] = remove_query_arg( 'year', $redirect['query'] );
}
}
} elseif ( is_author() && ! empty( $_GET['author'] )
&& is_string( $_GET['author'] ) && preg_match( '|^[0-9]+$|', $_GET['author'] )
) {
$author = get_userdata( get_query_var( 'author' ) );

if ( false !== $author
&& $wpdb->get_var( $wpdb->prepare( "SELECT ID FROM $wpdb->posts WHERE $wpdb->posts.post_author = %d AND $wpdb->posts.post_status = 'publish' LIMIT 1", $author->ID ) )
) {
$redirect_url = get_author_posts_url( $author->ID, $author->user_nicename );
$redirect_obj = $author;

if ( $redirect_url ) {
$redirect['query'] = remove_query_arg( 'author', $redirect['query'] );
}
}
} elseif ( is_category() || is_tag() || is_tax() ) { // Terms (tags/categories).
$term_count = 0;

foreach ( $wp_query->tax_query->queried_terms as $tax_query ) {
if ( isset( $tax_query['terms'] ) && is_countable( $tax_query['terms'] ) ) {
$term_count += count( $tax_query['terms'] );
}
}

$obj = $wp_query->get_queried_object();

if ( $term_count <= 1 && ! empty( $obj->term_id ) ) {
$tax_url = get_term_link( (int) $obj->term_id, $obj->taxonomy );

if ( $tax_url && ! is_wp_error( $tax_url ) ) {
if ( ! empty( $redirect['query'] ) ) {
// Strip taxonomy query vars off the URL.
$qv_remove = array( 'term', 'taxonomy' );

if ( is_category() ) {
$qv_remove[] = 'category_name';
$qv_remove[] = 'cat';
} elseif ( is_tag() ) {
$qv_remove[] = 'tag';
$qv_remove[] = 'tag_id';
} else {
// Custom taxonomies will have a custom query var, remove those too.
$tax_obj = get_taxonomy( $obj->taxonomy );
if ( false !== $tax_obj->query_var ) {
$qv_remove[] = $tax_obj->query_var;
}
}

$rewrite_vars = array_diff( array_keys( $wp_query->query ), array_keys( $_GET ) );

// Check to see if all the query vars are coming from the rewrite, none are set via $_GET.
if ( ! array_diff( $rewrite_vars, array_keys( $_GET ) ) ) {
// Remove all of the per-tax query vars.
$redirect['query'] = remove_query_arg( $qv_remove, $redirect['query'] );

// Create the destination URL for this taxonomy.
$tax_url = parse_url( $tax_url );

if ( ! empty( $tax_url['query'] ) ) {
// Taxonomy accessible via ?taxonomy=...&term=... or any custom query var.
parse_str( $tax_url['query'], $query_vars );
$redirect['query'] = add_query_arg( $query_vars, $redirect['query'] );
} else {
// Taxonomy is accessible via a "pretty URL".
$redirect['path'] = $tax_url['path'];
}
} else {
// Some query vars are set via $_GET. Unset those from $_GET that exist via the rewrite.
foreach ( $qv_remove as $_qv ) {
if ( isset( $rewrite_vars[ $_qv ] ) ) {
$redirect['query'] = remove_query_arg( $_qv, $redirect['query'] );
}
}
}
}
}
}
} elseif ( is_single() && str_contains( $wp_rewrite->permalink_structure, '%category%' ) ) {
$category_name = get_query_var( 'category_name' );

if ( $category_name ) {
$category = get_category_by_path( $category_name );

if ( ! $category || is_wp_error( $category )
|| ! has_term( $category->term_id, 'category', $wp_query->get_queried_object_id() )
) {
$redirect_url = get_permalink( $wp_query->get_queried_object_id() );
$redirect_obj = get_post( $wp_query->get_queried_object_id() );
}
}
}

// Post paging.
if ( is_singular() && get_query_var( 'page' ) ) {
$page = get_query_var( 'page' );

if ( ! $redirect_url ) {
$redirect_url = get_permalink( get_queried_object_id() );
$redirect_obj = get_post( get_queried_object_id() );
}

if ( $page > 1 ) {
$redirect_url = trailingslashit( $redirect_url );

if ( is_front_page() ) {
$redirect_url .= user_trailingslashit( "$wp_rewrite->pagination_base/$page", 'paged' );
} else {
$redirect_url .= user_trailingslashit( $page, 'single_paged' );
}
}

$redirect['query'] = remove_query_arg( 'page', $redirect['query'] );
}

if ( get_query_var( 'sitemap' ) ) {
$redirect_url = get_sitemap_url( get_query_var( 'sitemap' ), get_query_var( 'sitemap-subtype' ), get_query_var( 'paged' ) );
$redirect['query'] = remove_query_arg( array( 'sitemap', 'sitemap-subtype', 'paged' ), $redirect['query'] );
} elseif ( get_query_var( 'paged' ) || is_feed() || get_query_var( 'cpage' ) ) {
// Paging and feeds.
$paged = get_query_var( 'paged' );
$feed = get_query_var( 'feed' );
$cpage = get_query_var( 'cpage' );

while ( preg_match( "#/$wp_rewrite->pagination_base/?[0-9]+?(/+)?$#", $redirect['path'] )
|| preg_match( '#/(comments/?)?(feed|rss2?|rdf|atom)(/+)?$#', $redirect['path'] )
|| preg_match( "#/{$wp_rewrite->comments_pagination_base}-[0-9]+(/+)?$#", $redirect['path'] )
) {
// Strip off any existing paging.
$redirect['path'] = preg_replace( "#/$wp_rewrite->pagination_base/?[0-9]+?(/+)?$#", '/', $redirect['path'] );
// Strip off feed endings.
$redirect['path'] = preg_replace( '#/(comments/?)?(feed|rss2?|rdf|atom)(/+|$)#', '/', $redirect['path'] );
// Strip off any existing comment paging.
$redirect['path'] = preg_replace( "#/{$wp_rewrite->comments_pagination_base}-[0-9]+?(/+)?$#", '/', $redirect['path'] );
}

$addl_path = '';
$default_feed = get_default_feed();

if ( is_feed() && in_array( $feed, $wp_rewrite->feeds, true ) ) {
$addl_path = ! empty( $addl_path ) ? trailingslashit( $addl_path ) : '';

if ( ! is_singular() && get_query_var( 'withcomments' ) ) {
$addl_path .= 'comments/';
}

if ( ( 'rss' === $default_feed && 'feed' === $feed ) || 'rss' === $feed ) {
$format = ( 'rss2' === $default_feed ) ? '' : 'rss2';
} else {
$format = ( $default_feed === $feed || 'feed' === $feed ) ? '' : $feed;
}

$addl_path .= user_trailingslashit( 'feed/' . $format, 'feed' );

$redirect['query'] = remove_query_arg( 'feed', $redirect['query'] );
} elseif ( is_feed() && 'old' === $feed ) {
$old_feed_files = array(
'wp-atom.php' => 'atom',
'wp-commentsrss2.php' => 'comments_rss2',
'wp-feed.php' => $default_feed,
'wp-rdf.php' => 'rdf',
'wp-rss.php' => 'rss2',
'wp-rss2.php' => 'rss2',
);

if ( isset( $old_feed_files[ basename( $redirect['path'] ) ] ) ) {
$redirect_url = get_feed_link( $old_feed_files[ basename( $redirect['path'] ) ] );

wp_redirect( $redirect_url, 301 );
die();
}
}

if ( $paged > 0 ) {
$redirect['query'] = remove_query_arg( 'paged', $redirect['query'] );

if ( ! is_feed() ) {
if ( ! is_single() ) {
$addl_path = ! empty( $addl_path ) ? trailingslashit( $addl_path ) : '';

if ( $paged > 1 ) {
$addl_path .= user_trailingslashit( "$wp_rewrite->pagination_base/$paged", 'paged' );
}
}
} elseif ( $paged > 1 ) {
$redirect['query'] = add_query_arg( 'paged', $paged, $redirect['query'] );
}
}

$default_comments_page = get_option( 'default_comments_page' );

if ( get_option( 'page_comments' )
&& ( 'newest' === $default_comments_page && $cpage > 0
|| 'newest' !== $default_comments_page && $cpage > 1 )
) {
$addl_path = ( ! empty( $addl_path ) ? trailingslashit( $addl_path ) : '' );
$addl_path .= user_trailingslashit( $wp_rewrite->comments_pagination_base . '-' . $cpage, 'commentpaged' );

$redirect['query'] = remove_query_arg( 'cpage', $redirect['query'] );
}

// Strip off trailing /index.php/.
$redirect['path'] = preg_replace( '|/' . preg_quote( $wp_rewrite->index, '|' ) . '/?$|', '/', $redirect['path'] );
$redirect['path'] = user_trailingslashit( $redirect['path'] );

if ( ! empty( $addl_path )
&& $wp_rewrite->using_index_permalinks()
&& ! str_contains( $redirect['path'], '/' . $wp_rewrite->index . '/' )
) {
$redirect['path'] = trailingslashit( $redirect['path'] ) . $wp_rewrite->index . '/';
}

if ( ! empty( $addl_path ) ) {
$redirect['path'] = trailingslashit( $redirect['path'] ) . $addl_path;
}

$redirect_url = $redirect['scheme'] . '://' . $redirect['host'] . $redirect['path'];
}

if ( 'wp-register.php' === basename( $redirect['path'] ) ) {
if ( is_multisite() ) {
/** This filter is documented in wp-login.php */
$redirect_url = apply_filters( 'wp_signup_location', network_site_url( 'wp-signup.php' ) );
} else {
$redirect_url = wp_registration_url();
}

wp_redirect( $redirect_url, 301 );
die();
}
}

$is_attachment_redirect = false;

if ( is_attachment() && ! get_option( 'wp_attachment_pages_enabled' ) ) {
$attachment_id = get_query_var( 'attachment_id' );
$attachment_post = get_post( $attachment_id );
$attachment_parent_id = $attachment_post ? $attachment_post->post_parent : 0;
$attachment_url = wp_get_attachment_url( $attachment_id );

if ( $attachment_url !== $redirect_url ) {
/*
* If an attachment is attached to a post, it inherits the parent post's status.
* Fetch the parent post to check its status later.
*/
if ( $attachment_parent_id ) {
$redirect_obj = get_post( $attachment_parent_id );
}

$redirect_url = $attachment_url;
}

$is_attachment_redirect = true;
}

$redirect['query'] = preg_replace( '#^\??&*?#', '', $redirect['query'] );

// Tack on any additional query vars.
if ( $redirect_url && ! empty( $redirect['query'] ) ) {
parse_str( $redirect['query'], $_parsed_query );
$redirect = parse_url( $redirect_url );

if ( ! empty( $_parsed_query['name'] ) && ! empty( $redirect['query'] ) ) {
parse_str( $redirect['query'], $_parsed_redirect_query );

if ( empty( $_parsed_redirect_query['name'] ) ) {
unset( $_parsed_query['name'] );
}
}

$_parsed_query = array_combine(
rawurlencode_deep( array_keys( $_parsed_query ) ),
rawurlencode_deep( array_values( $_parsed_query ) )
);

$redirect_url = add_query_arg( $_parsed_query, $redirect_url );
}

if ( $redirect_url ) {
$redirect = parse_url( $redirect_url );
}

// www.example.com vs. example.com
$user_home = parse_url( home_url() );

if ( ! empty( $user_home['host'] ) ) {
$redirect['host'] = $user_home['host'];
}

if ( empty( $user_home['path'] ) ) {
$user_home['path'] = '/';
}

// Handle ports.
if ( ! empty( $user_home['port'] ) ) {
$redirect['port'] = $user_home['port'];
} else {
unset( $redirect['port'] );
}

// Trailing /index.php.
$redirect['path'] = preg_replace( '|/' . preg_quote( $wp_rewrite->index, '|' ) . '/*?$|', '/', $redirect['path'] );

$punctuation_pattern = implode(
'|',
array_map(
'preg_quote',
array(
' ',
'%20', // Space.
'!',
'%21', // Exclamation mark.
'"',
'%22', // Double quote.
"'",
'%27', // Single quote.
'(',
'%28', // Opening bracket.
')',
'%29', // Closing bracket.
',',
'%2C', // Comma.
'.',
'%2E', // Period.
';',
'%3B', // Semicolon.
'{',
'%7B', // Opening curly bracket.
'}',
'%7D', // Closing curly bracket.
'%E2%80%9C', // Opening curly quote.
'%E2%80%9D', // Closing curly quote.
)
)
);

// Remove trailing spaces and end punctuation from the path.
$redirect['path'] = preg_replace( "#($punctuation_pattern)+$#", '', $redirect['path'] );

if ( ! empty( $redirect['query'] ) ) {
// Remove trailing spaces and end punctuation from certain terminating query string args.
$redirect['query'] = preg_replace( "#((^|&)(p|page_id|cat|tag)=[^&]*?)($punctuation_pattern)+$#", '$1', $redirect['query'] );

// Clean up empty query strings.
$redirect['query'] = trim( preg_replace( '#(^|&)(p|page_id|cat|tag)=?(&|$)#', '&', $redirect['query'] ), '&' );

// Redirect obsolete feeds.
$redirect['query'] = preg_replace( '#(^|&)feed=rss(&|$)#', '$1feed=rss2$2', $redirect['query'] );

// Remove redundant leading ampersands.
$redirect['query'] = preg_replace( '#^\??&*?#', '', $redirect['query'] );
}

// Strip /index.php/ when we're not using PATHINFO permalinks.
if ( ! $wp_rewrite->using_index_permalinks() ) {
$redirect['path'] = str_replace( '/' . $wp_rewrite->index . '/', '/', $redirect['path'] );
}

// Trailing slashes.
if ( is_object( $wp_rewrite ) && $wp_rewrite->using_permalinks()
&& ! $is_attachment_redirect
&& ! is_404() && ( ! is_front_page() || is_front_page() && get_query_var( 'paged' ) > 1 )
) {
$user_ts_type = '';

if ( get_query_var( 'paged' ) > 0 ) {
$user_ts_type = 'paged';
} else {
foreach ( array( 'single', 'category', 'page', 'day', 'month', 'year', 'home' ) as $type ) {
$func = 'is_' . $type;
if ( call_user_func( $func ) ) {
$user_ts_type = $type;
break;
}
}
}

$redirect['path'] = user_trailingslashit( $redirect['path'], $user_ts_type );
} elseif ( is_front_page() ) {
$redirect['path'] = trailingslashit( $redirect['path'] );
}

// Remove trailing slash for robots.txt or sitemap requests.
if ( is_robots()
|| ! empty( get_query_var( 'sitemap' ) ) || ! empty( get_query_var( 'sitemap-stylesheet' ) )
) {
$redirect['path'] = untrailingslashit( $redirect['path'] );
}

// Strip multiple slashes out of the URL.
if ( str_contains( $redirect['path'], '//' ) ) {
$redirect['path'] = preg_replace( '|/+|', '/', $redirect['path'] );
}

// Always trailing slash the Front Page URL.
if ( trailingslashit( $redirect['path'] ) === trailingslashit( $user_home['path'] ) ) {
$redirect['path'] = trailingslashit( $redirect['path'] );
}

$original_host_low = strtolower( $original['host'] );
$redirect_host_low = strtolower( $redirect['host'] );

/*
* Ignore differences in host capitalization, as this can lead to infinite redirects.
* Only redirect no-www <=> yes-www.
*/
if ( $original_host_low === $redirect_host_low
|| ( 'www.' . $original_host_low !== $redirect_host_low
&& 'www.' . $redirect_host_low !== $original_host_low )
) {
$redirect['host'] = $original['host'];
}

$compare_original = array( $original['host'], $original['path'] );

if ( ! empty( $original['port'] ) ) {
$compare_original[] = $original['port'];
}

if ( ! empty( $original['query'] ) ) {
$compare_original[] = $original['query'];
}

$compare_redirect = array( $redirect['host'], $redirect['path'] );

if ( ! empty( $redirect['port'] ) ) {
$compare_redirect[] = $redirect['port'];
}

if ( ! empty( $redirect['query'] ) ) {
$compare_redirect[] = $redirect['query'];
}

if ( $compare_original !== $compare_redirect ) {
$redirect_url = $redirect['scheme'] . '://' . $redirect['host'];

if ( ! empty( $redirect['port'] ) ) {
$redirect_url .= ':' . $redirect['port'];
}

$redirect_url .= $redirect['path'];

if ( ! empty( $redirect['query'] ) ) {
$redirect_url .= '?' . $redirect['query'];
}
}

if ( ! $redirect_url || $redirect_url === $requested_url ) {
return;
}

// Hex-encoded octets are case-insensitive.
if ( str_contains( $requested_url, '%' ) ) {
if ( ! function_exists( 'lowercase_octets' ) ) {
/**
* Converts the first hex-encoded octet match to lowercase.
*
* @since 3.1.0
* @ignore
*
* @param array $matches Hex-encoded octet matches for the requested URL.
* @return string Lowercased version of the first match.
*/
function lowercase_octets( $matches ) {
return strtolower( $matches[0] );
}
}

$requested_url = preg_replace_callback( '|%[a-fA-F0-9][a-fA-F0-9]|', 'lowercase_octets', $requested_url );
}

if ( $redirect_obj instanceof WP_Post ) {
$post_status_obj = get_post_status_object( get_post_status( $redirect_obj ) );
/*
* Unset the redirect object and URL if they are not readable by the user.
* This condition is a little confusing as the condition needs to pass if
* the post is not readable by the user. That's why there are ! (not) conditions
* throughout.
*/
if (
// Private post statuses only redirect if the user can read them.
! (
$post_status_obj->private &&
current_user_can( 'read_post', $redirect_obj->ID )
) &&
// For other posts, only redirect if publicly viewable.
! is_post_publicly_viewable( $redirect_obj )
) {
$redirect_obj = false;
$redirect_url = false;
}
}

/**
* Filters the canonical redirect URL.
*
* Returning false to this filter will cancel the redirect.
*
* @since 2.3.0
*
* @param string $redirect_url The redirect URL.
* @param string $requested_url The requested URL.
*/
$redirect_url = apply_filters( 'redirect_canonical', $redirect_url, $requested_url );

// Yes, again -- in case the filter aborted the request.
if ( ! $redirect_url || strip_fragment_from_url( $redirect_url ) === strip_fragment_from_url( $requested_url ) ) {
return;
}

if ( $do_redirect ) {
// Protect against chained redirects.
if ( ! redirect_canonical( $redirect_url, false ) ) {
wp_redirect( $redirect_url, 301 );
exit;
} else {
// Debug.
// die("1: $redirect_url<br />2: " . redirect_canonical( $redirect_url, false ) );
return;
}
} else {
return $redirect_url;
}
}

/**
* Removes arguments from a query string if they are not present in a URL
* DO NOT use this in plugin code.
*
* @since 3.4.0
* @access private
*
* @param string $query_string
* @param array $args_to_check
* @param string $url
* @return string The altered query string
*/
function _remove_qs_args_if_not_in_url( $query_string, array $args_to_check, $url ) {
$parsed_url = parse_url( $url );

if ( ! empty( $parsed_url['query'] ) ) {
parse_str( $parsed_url['query'], $parsed_query );

foreach ( $args_to_check as $qv ) {
if ( ! isset( $parsed_query[ $qv ] ) ) {
$query_string = remove_query_arg( $qv, $query_string );
}
}
} else {
$query_string = remove_query_arg( $args_to_check, $query_string );
}

return $query_string;
}

/**
* Strips the #fragment from a URL, if one is present.
*
* @since 4.4.0
*
* @param string $url The URL to strip.
* @return string The altered URL.
*/
function strip_fragment_from_url( $url ) {
$parsed_url = wp_parse_url( $url );

if ( ! empty( $parsed_url['host'] ) ) {
$url = '';

if ( ! empty( $parsed_url['scheme'] ) ) {
$url = $parsed_url['scheme'] . ':';
}

$url .= '//' . $parsed_url['host'];

if ( ! empty( $parsed_url['port'] ) ) {
$url .= ':' . $parsed_url['port'];
}

if ( ! empty( $parsed_url['path'] ) ) {
$url .= $parsed_url['path'];
}

if ( ! empty( $parsed_url['query'] ) ) {
$url .= '?' . $parsed_url['query'];
}
}

return $url;
}

/**
* Attempts to guess the correct URL for a 404 request based on query vars.
*
* @since 2.3.0
*
* @global wpdb $wpdb WordPress database abstraction object.
*
* @return string|false The correct URL if one is found. False on failure.
*/
function redirect_guess_404_permalink() {
global $wpdb;

/**
* Filters whether to attempt to guess a redirect URL for a 404 request.
*
* Returning a false value from the filter will disable the URL guessing
* and return early without performing a redirect.
*
* @since 5.5.0
*
* @param bool $do_redirect_guess Whether to attempt to guess a redirect URL
* for a 404 request. Default true.
*/
if ( false === apply_filters( 'do_redirect_guess_404_permalink', true ) ) {
return false;
}

/**
* Short-circuits the redirect URL guessing for 404 requests.
*
* Returning a non-null value from the filter will effectively short-circuit
* the URL guessing, returning the passed value instead.
*
* @since 5.5.0
*
* @param null|string|false $pre Whether to short-circuit guessing the redirect for a 404.
* Default null to continue with the URL guessing.
*/
$pre = apply_filters( 'pre_redirect_guess_404_permalink', null );
if ( null !== $pre ) {
return $pre;
}

if ( get_query_var( 'name' ) ) {
$publicly_viewable_statuses = array_filter( get_post_stati(), 'is_post_status_viewable' );
$publicly_viewable_post_types = array_filter( get_post_types( array( 'exclude_from_search' => false ) ), 'is_post_type_viewable' );

/**
* Filters whether to perform a strict guess for a 404 redirect.
*
* Returning a truthy value from the filter will redirect only exact post_name matches.
*
* @since 5.5.0
*
* @param bool $strict_guess Whether to perform a strict guess. Default false (loose guess).
*/
$strict_guess = apply_filters( 'strict_redirect_guess_404_permalink', false );

if ( $strict_guess ) {
$where = $wpdb->prepare( 'post_name = %s', get_query_var( 'name' ) );
} else {
$where = $wpdb->prepare( 'post_name LIKE %s', $wpdb->esc_like( get_query_var( 'name' ) ) . '%' );
}

// If any of post_type, year, monthnum, or day are set, use them to refine the query.
if ( get_query_var( 'post_type' ) ) {
if ( is_array( get_query_var( 'post_type' ) ) ) {
$post_types = array_intersect( get_query_var( 'post_type' ), $publicly_viewable_post_types );
if ( empty( $post_types ) ) {
return false;
}
$where .= " AND post_type IN ('" . join( "', '", esc_sql( get_query_var( 'post_type' ) ) ) . "')";
} else {
if ( ! in_array( get_query_var( 'post_type' ), $publicly_viewable_post_types, true ) ) {
return false;
}
$where .= $wpdb->prepare( ' AND post_type = %s', get_query_var( 'post_type' ) );
}
} else {
$where .= " AND post_type IN ('" . implode( "', '", esc_sql( $publicly_viewable_post_types ) ) . "')";
}

if ( get_query_var( 'year' ) ) {
$where .= $wpdb->prepare( ' AND YEAR(post_date) = %d', get_query_var( 'year' ) );
}
if ( get_query_var( 'monthnum' ) ) {
$where .= $wpdb->prepare( ' AND MONTH(post_date) = %d', get_query_var( 'monthnum' ) );
}
if ( get_query_var( 'day' ) ) {
$where .= $wpdb->prepare( ' AND DAYOFMONTH(post_date) = %d', get_query_var( 'day' ) );
}

// phpcs:ignore WordPress.DB.PreparedSQL.InterpolatedNotPrepared
$post_id = $wpdb->get_var( "SELECT ID FROM $wpdb->posts WHERE $where AND post_status IN ('" . implode( "', '", esc_sql( $publicly_viewable_statuses ) ) . "')" );

if ( ! $post_id ) {
return false;
}

if ( get_query_var( 'feed' ) ) {
return get_post_comments_feed_link( $post_id, get_query_var( 'feed' ) );
} elseif ( get_query_var( 'page' ) > 1 ) {
return trailingslashit( get_permalink( $post_id ) ) . user_trailingslashit( get_query_var( 'page' ), 'single_paged' );
} else {
return get_permalink( $post_id );
}
}

return false;
}

/**
* Redirects a variety of shorthand URLs to the admin.
*
* If a user visits example.com/admin, they'll be redirected to /wp-admin.
* Visiting /login redirects to /wp-login.php, and so on.
*
* @since 3.4.0
*
* @global WP_Rewrite $wp_rewrite WordPress rewrite component.
*/
function wp_redirect_admin_locations() {
global $wp_rewrite;

if ( ! ( is_404() && $wp_rewrite->using_permalinks() ) ) {
return;
}

$admins = array(
home_url( 'wp-admin', 'relative' ),
home_url( 'dashboard', 'relative' ),
home_url( 'admin', 'relative' ),
site_url( 'dashboard', 'relative' ),
site_url( 'admin', 'relative' ),
);

if ( in_array( untrailingslashit( $_SERVER['REQUEST_URI'] ), $admins, true ) ) {
wp_redirect( admin_url() );
exit;
}

$logins = array(
home_url( 'wp-login.php', 'relative' ),
home_url( 'login.php', 'relative' ),
home_url( 'login', 'relative' ),
site_url( 'login', 'relative' ),
);

if ( in_array( untrailingslashit( $_SERVER['REQUEST_URI'] ), $logins, true ) ) {
wp_redirect( wp_login_url() );
exit;
}
}