From 98fb5f0bdbb8ef86ee96630924715749d2efc620 Mon Sep 17 00:00:00 2001
From: Boone Gorges <boonebgorges@gmail.com>
Date: Wed, 13 Jan 2016 04:01:26 +0000
Subject: [PATCH] Use the post-filter WHERE clause when querying for comment
 descendants.

The descendant query in `WP_Comment_Query::fill_descendants()` uses the clauses
of the main `get_comment_ids()` query as a basis, discarding the `parent`,
`parent__in`, and `parent__not_in` clauses. As implemented in WP 4.4 [34546],
the WHERE clause was assembled in such a way that any modifications applied
using the `comments_clauses` filter were not inherited by `fill_descendants()`.
This resulted in descendant queries that did not always properly filter
results, and sometimes contained syntax errors.

The current changeset fixes the problem by using the post-filter WHERE clause
as the basis for the `fill_descendants()` query. This change requires a new
approach for eliminating the unneeded parent-related clauses: instead of
eliminating values in an associative array, we must use regular expressions.

Props boonebgorges, firebird75.
Fixes #35192.
Built from https://develop.svn.wordpress.org/trunk@36277


git-svn-id: http://core.svn.wordpress.org/trunk@36244 1a063a9b-81f0-0310-95a4-ce76da25c4cd
---
 wp-includes/class-wp-comment-query.php | 42 +++++++++++++++++++++-----
 wp-includes/version.php                |  2 +-
 2 files changed, 36 insertions(+), 8 deletions(-)

diff --git a/wp-includes/class-wp-comment-query.php b/wp-includes/class-wp-comment-query.php
index ac122a62c9..ccbf10c31b 100644
--- a/wp-includes/class-wp-comment-query.php
+++ b/wp-includes/class-wp-comment-query.php
@@ -59,6 +59,17 @@ class WP_Comment_Query {
 		'limits'  => '',
 	);
 
+	/**
+	 * SQL WHERE clause.
+	 *
+	 * Stored after the 'comments_clauses' filter is run on the compiled WHERE sub-clauses.
+	 *
+	 * @since 4.4.2
+	 * @access protected
+	 * @var string
+	 */
+	protected $filtered_where_clause;
+
 	/**
 	 * Date query container
 	 *
@@ -823,6 +834,8 @@ class WP_Comment_Query {
 		$limits = isset( $clauses[ 'limits' ] ) ? $clauses[ 'limits' ] : '';
 		$groupby = isset( $clauses[ 'groupby' ] ) ? $clauses[ 'groupby' ] : '';
 
+		$this->filtered_where_clause = $where;
+
 		if ( $where ) {
 			$where = 'WHERE ' . $where;
 		}
@@ -874,12 +887,27 @@ class WP_Comment_Query {
 			0 => wp_list_pluck( $comments, 'comment_ID' ),
 		);
 
-		$where_clauses = $this->sql_clauses['where'];
-		unset(
-			$where_clauses['parent'],
-			$where_clauses['parent__in'],
-			$where_clauses['parent__not_in']
-		);
+		/*
+		 * The WHERE clause for the descendant query is the same as for the top-level
+		 * query, minus the `parent`, `parent__in`, and `parent__not_in` sub-clauses.
+		 */
+		$_where = $this->filtered_where_clause;
+		$exclude_keys = array( 'parent', 'parent__in', 'parent__not_in' );
+		foreach ( $exclude_keys as $exclude_key ) {
+			if ( isset( $this->sql_clauses['where'][ $exclude_key ] ) ) {
+				$clause = $this->sql_clauses['where'][ $exclude_key ];
+
+				// Strip the clause as well as any adjacent ANDs.
+				$pattern = '|(?:AND)?\s*' . $clause . '\s*(?:AND)?|';
+				$_where_parts = preg_split( $pattern, $_where );
+
+				// Remove empties.
+				$_where_parts = array_filter( array_map( 'trim', $_where_parts ) );
+
+				// Reassemble with an AND.
+				$_where = implode( ' AND ', $_where_parts );
+			}
+		}
 
 		// Fetch an entire level of the descendant tree at a time.
 		$level = 0;
@@ -889,7 +917,7 @@ class WP_Comment_Query {
 				break;
 			}
 
-			$where = 'WHERE ' . implode( ' AND ', $where_clauses ) . ' AND comment_parent IN (' . implode( ',', array_map( 'intval', $parent_ids ) ) . ')';
+			$where = 'WHERE ' . $_where . ' AND comment_parent IN (' . implode( ',', array_map( 'intval', $parent_ids ) ) . ')';
 			$comment_ids = $wpdb->get_col( "{$this->sql_clauses['select']} {$this->sql_clauses['from']} {$where} {$this->sql_clauses['groupby']} ORDER BY comment_date_gmt ASC, comment_ID ASC" );
 
 			$level++;
diff --git a/wp-includes/version.php b/wp-includes/version.php
index a38d7d88a9..9e2f12cb92 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '4.5-alpha-36276';
+$wp_version = '4.5-alpha-36277';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.