From f3441e37eddc5f98ffbe2c51ceebf800797e6d7f Mon Sep 17 00:00:00 2001
From: Sergey Biryukov <sergeybiryukov@git.wordpress.org>
Date: Tue, 14 Jun 2022 16:15:52 +0000
Subject: [PATCH] Docs: Add a comment for stripping the leading `AND` from SQL
 clauses in some query classes.

Follow-up to [30084], [34529], [34542], [36598], [37477], [37572], [43010].

See #55646.

git-svn-id: https://develop.svn.wordpress.org/trunk@53503 602fd350-edb4-49c9-b593-d223f7449a82
---
 src/wp-includes/class-wp-comment-query.php |  4 +++-
 src/wp-includes/class-wp-site-query.php    |  4 +++-
 src/wp-includes/class-wp-term-query.php    | 20 ++++++++++++++++----
 3 files changed, 22 insertions(+), 6 deletions(-)

diff --git a/src/wp-includes/class-wp-comment-query.php b/src/wp-includes/class-wp-comment-query.php
index 6f317b57c2..6b72bc88d9 100644
--- a/src/wp-includes/class-wp-comment-query.php
+++ b/src/wp-includes/class-wp-comment-query.php
@@ -911,7 +911,9 @@ class WP_Comment_Query {
 		}
 
 		if ( ! empty( $this->query_vars['date_query'] ) && is_array( $this->query_vars['date_query'] ) ) {
-			$this->date_query                         = new WP_Date_Query( $this->query_vars['date_query'], 'comment_date' );
+			$this->date_query = new WP_Date_Query( $this->query_vars['date_query'], 'comment_date' );
+
+			// Strip leading 'AND'.
 			$this->sql_clauses['where']['date_query'] = preg_replace( '/^\s*AND\s*/', '', $this->date_query->get_sql() );
 		}
 
diff --git a/src/wp-includes/class-wp-site-query.php b/src/wp-includes/class-wp-site-query.php
index 97158a2f2a..18961253f1 100644
--- a/src/wp-includes/class-wp-site-query.php
+++ b/src/wp-includes/class-wp-site-query.php
@@ -626,7 +626,9 @@ class WP_Site_Query {
 
 		$date_query = $this->query_vars['date_query'];
 		if ( ! empty( $date_query ) && is_array( $date_query ) ) {
-			$this->date_query                         = new WP_Date_Query( $date_query, 'registered' );
+			$this->date_query = new WP_Date_Query( $date_query, 'registered' );
+
+			// Strip leading 'AND'.
 			$this->sql_clauses['where']['date_query'] = preg_replace( '/^\s*AND\s*/', '', $this->date_query->get_sql() );
 		}
 
diff --git a/src/wp-includes/class-wp-term-query.php b/src/wp-includes/class-wp-term-query.php
index eb3e769fe0..5c430c8459 100644
--- a/src/wp-includes/class-wp-term-query.php
+++ b/src/wp-includes/class-wp-term-query.php
@@ -484,6 +484,7 @@ class WP_Term_Query {
 		if ( ! empty( $exclude_tree ) ) {
 			$exclude_tree      = wp_parse_id_list( $exclude_tree );
 			$excluded_children = $exclude_tree;
+
 			foreach ( $exclude_tree as $extrunk ) {
 				$excluded_children = array_merge(
 					$excluded_children,
@@ -497,6 +498,7 @@ class WP_Term_Query {
 					)
 				);
 			}
+
 			$exclusions = array_merge( $excluded_children, $exclusions );
 		}
 
@@ -531,7 +533,7 @@ class WP_Term_Query {
 		$exclusions = apply_filters( 'list_terms_exclusions', $exclusions, $args, $taxonomies );
 
 		if ( ! empty( $exclusions ) ) {
-			// Must do string manipulation here for backward compatibility with filter.
+			// Strip leading 'AND'. Must do string manipulation here for backward compatibility with filter.
 			$this->sql_clauses['where']['exclusions'] = preg_replace( '/^\s*AND\s*/', '', $exclusions );
 		}
 
@@ -543,6 +545,7 @@ class WP_Term_Query {
 
 		if ( ! empty( $args['name'] ) ) {
 			$names = $args['name'];
+
 			foreach ( $names as &$_name ) {
 				// `sanitize_term_field()` returns slashed data.
 				$_name = stripslashes( sanitize_term_field( 'name', $_name, 0, reset( $taxonomies ), 'db' ) );
@@ -650,9 +653,12 @@ class WP_Term_Query {
 		$meta_clauses = $this->meta_query->get_clauses();
 
 		if ( ! empty( $meta_clauses ) ) {
-			$join                                    .= $mq_sql['join'];
+			$join .= $mq_sql['join'];
+
+			// Strip leading 'AND'.
 			$this->sql_clauses['where']['meta_query'] = preg_replace( '/^\s*AND\s*/', '', $mq_sql['where'] );
-			$distinct                                .= 'DISTINCT';
+
+			$distinct .= 'DISTINCT';
 
 		}
 
@@ -785,12 +791,16 @@ class WP_Term_Query {
 			if ( 'ids' === $_fields ) {
 				$cache = array_map( 'intval', $cache );
 			} elseif ( 'count' !== $_fields ) {
-				if ( ( 'all_with_object_id' === $_fields && ! empty( $args['object_ids'] ) ) || ( 'all' === $_fields && $args['pad_counts'] ) ) {
+				if ( ( 'all_with_object_id' === $_fields && ! empty( $args['object_ids'] ) )
+					|| ( 'all' === $_fields && $args['pad_counts'] )
+				) {
 					$term_ids = wp_list_pluck( $cache, 'term_id' );
 				} else {
 					$term_ids = array_map( 'intval', $cache );
 				}
+
 				_prime_term_caches( $term_ids, $args['update_term_meta_cache'] );
+
 				$term_objects = $this->populate_terms( $cache );
 				$cache        = $this->format_terms( $term_objects, $_fields );
 			}
@@ -837,6 +847,7 @@ class WP_Term_Query {
 			foreach ( $term_objects as $k => $term ) {
 				if ( ! $term->count ) {
 					$children = get_term_children( $term->term_id, $term->taxonomy );
+
 					if ( is_array( $children ) ) {
 						foreach ( $children as $child_id ) {
 							$child = get_term( $child_id, $term->taxonomy );
@@ -886,6 +897,7 @@ class WP_Term_Query {
 		} else {
 			$term_cache = wp_list_pluck( $term_objects, 'term_id' );
 		}
+
 		wp_cache_add( $cache_key, $term_cache, 'terms' );
 		$this->terms = $this->format_terms( $term_objects, $_fields );