From 72a264e9c050ebd96790f13a7e3f29cce38e5732 Mon Sep 17 00:00:00 2001
From: Boone Gorges <boonebgorges@gmail.com>
Date: Fri, 18 Dec 2015 17:49:22 +0000
Subject: [PATCH] Ensure `get_terms()` results are unique when using
 'meta_query'.

The introduction of 'meta_query' to `get_terms()` in 4.4 made it possible for
`get_terms()` to erroneously return duplicate results. To address the issue,
we add the `DISTINCT` keyword to the SQL query when a 'meta_query' parameter
has been provided.

Merges [36003] to the 4.4 branch.

Props @jadpm.
Fixes #35137.

Built from https://develop.svn.wordpress.org/branches/4.4@36004


git-svn-id: http://core.svn.wordpress.org/branches/4.4@35969 1a063a9b-81f0-0310-95a4-ce76da25c4cd
---
 wp-includes/taxonomy.php | 7 +++++--
 wp-includes/version.php  | 2 +-
 2 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/wp-includes/taxonomy.php b/wp-includes/taxonomy.php
index f361c3be49..3dcdede818 100644
--- a/wp-includes/taxonomy.php
+++ b/wp-includes/taxonomy.php
@@ -1353,12 +1353,14 @@ function get_terms( $taxonomies, $args = '' ) {
 
 	// Meta query support.
 	$join = '';
+	$distinct = '';
 	if ( ! empty( $args['meta_query'] ) ) {
 		$mquery = new WP_Meta_Query( $args['meta_query'] );
 		$mq_sql = $mquery->get_sql( 'term', 't', 'term_id' );
 
 		$join  .= $mq_sql['join'];
 		$where .= $mq_sql['where'];
+		$distinct .= "DISTINCT";
 	}
 
 	$selects = array();
@@ -1408,7 +1410,7 @@ function get_terms( $taxonomies, $args = '' ) {
 
 	$join .= " INNER JOIN $wpdb->term_taxonomy AS tt ON t.term_id = tt.term_id";
 
-	$pieces = array( 'fields', 'join', 'where', 'orderby', 'order', 'limits' );
+	$pieces = array( 'fields', 'join', 'where', 'distinct', 'orderby', 'order', 'limits' );
 
 	/**
 	 * Filter the terms query SQL clauses.
@@ -1424,11 +1426,12 @@ function get_terms( $taxonomies, $args = '' ) {
 	$fields = isset( $clauses[ 'fields' ] ) ? $clauses[ 'fields' ] : '';
 	$join = isset( $clauses[ 'join' ] ) ? $clauses[ 'join' ] : '';
 	$where = isset( $clauses[ 'where' ] ) ? $clauses[ 'where' ] : '';
+	$distinct = isset( $clauses[ 'distinct' ] ) ? $clauses[ 'distinct' ] : '';
 	$orderby = isset( $clauses[ 'orderby' ] ) ? $clauses[ 'orderby' ] : '';
 	$order = isset( $clauses[ 'order' ] ) ? $clauses[ 'order' ] : '';
 	$limits = isset( $clauses[ 'limits' ] ) ? $clauses[ 'limits' ] : '';
 
-	$query = "SELECT $fields FROM $wpdb->terms AS t $join WHERE $where $orderby $order $limits";
+	$query = "SELECT $distinct $fields FROM $wpdb->terms AS t $join WHERE $where $orderby $order $limits";
 
 	// $args can be anything. Only use the args defined in defaults to compute the key.
 	$key = md5( serialize( wp_array_slice_assoc( $args, array_keys( $defaults ) ) ) . serialize( $taxonomies ) . $query );
diff --git a/wp-includes/version.php b/wp-includes/version.php
index 880aabfed6..49a138af4c 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '4.4.1-alpha-35945';
+$wp_version = '4.4.1-alpha-36004';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.