From b9d46425c0b53dad0198c41ffe3a31cf110d59e7 Mon Sep 17 00:00:00 2001
From: Boone Gorges <boonebgorges@git.wordpress.org>
Date: Sat, 11 Jun 2016 03:48:03 +0000
Subject: [PATCH] Introduce `term_taxonomy_id` parameter for `WP_Term_Query`.

Allows the fetching of terms based on `term_taxonomy_id`, or an array of
`term_taxonomy_ids`.

Props spacedmonkey.
Fixes #37074.

git-svn-id: https://develop.svn.wordpress.org/trunk@37683 602fd350-edb4-49c9-b593-d223f7449a82
---
 src/wp-includes/class-wp-term-query.php | 13 +++++
 tests/phpunit/tests/term/query.php      | 64 +++++++++++++++++++++++++
 2 files changed, 77 insertions(+)
 create mode 100644 tests/phpunit/tests/term/query.php

diff --git a/src/wp-includes/class-wp-term-query.php b/src/wp-includes/class-wp-term-query.php
index 31fcf37462..924a1e8c4d 100644
--- a/src/wp-includes/class-wp-term-query.php
+++ b/src/wp-includes/class-wp-term-query.php
@@ -92,6 +92,7 @@ class WP_Term_Query {
 	 * Sets up the term query, based on the query vars passed.
 	 *
 	 * @since 4.6.0
+	 * @since 4.6.0 Introduced 'term_taxonomy_id' parameter.
 	 * @access public
 	 *
 	 * @param string|array $query {
@@ -136,6 +137,8 @@ class WP_Term_Query {
 	 *                                                Default empty.
 	 *     @type string|array $slug                   Optional. Slug or array of slugs to return term(s) for.
 	 *                                                Default empty.
+	 *     @type int|array    $term_taxonomy_id       Optional. Term taxonomy ID, or array of term taxonomy IDs,
+	 *                                                to match when querying terms.
 	 *     @type bool         $hierarchical           Whether to include terms that have non-empty descendants (even
 	 *                                                if $hide_empty is set to true). Default true.
 	 *     @type string       $search                 Search criteria to match terms. Will be SQL-formatted with
@@ -183,6 +186,7 @@ class WP_Term_Query {
 			'count'                  => false,
 			'name'                   => '',
 			'slug'                   => '',
+			'term_taxonomy_id'       => '',
 			'hierarchical'           => true,
 			'search'                 => '',
 			'name__like'             => '',
@@ -473,6 +477,15 @@ class WP_Term_Query {
 			}
 		}
 
+		if ( ! empty( $args['term_taxonomy_id'] ) ) {
+			if ( is_array( $args['term_taxonomy_id'] ) ) {
+				$tt_ids = implode( ',', array_map( 'intval', $args['term_taxonomy_id'] ) );
+				$this->sql_clauses['where']['term_taxonomy_id'] = "tt.term_taxonomy_id IN ({$tt_ids})";
+			} else {
+				$this->sql_clauses['where']['term_taxonomy_id'] = $wpdb->prepare( "tt.term_taxonomy_id = %d", $args['term_taxonomy_id'] );
+			}
+		}
+
 		if ( ! empty( $args['name__like'] ) ) {
 			$this->sql_clauses['where']['name__like'] = $wpdb->prepare( "t.name LIKE %s", '%' . $wpdb->esc_like( $args['name__like'] ) . '%' );
 		}
diff --git a/tests/phpunit/tests/term/query.php b/tests/phpunit/tests/term/query.php
new file mode 100644
index 0000000000..d1f875bcaa
--- /dev/null
+++ b/tests/phpunit/tests/term/query.php
@@ -0,0 +1,64 @@
+<?php
+
+/**
+ * @group taxonomy
+ */
+class Tests_Term_Query extends WP_UnitTestCase {
+	/**
+	 * @ticket 37074
+	 */
+	public function test_term_taxonomy_id_single() {
+		global $wpdb;
+
+		register_taxonomy( 'wptests_tax', 'post' );
+
+		$terms = self::factory()->term->create_many( 2, array( 'taxonomy' => 'wptests_tax' ) );
+
+		// Manually change the term_taxonomy_id to something else.
+		$wpdb->update(
+			$wpdb->term_taxonomy,
+			array( 'term_taxonomy_id' => 12345 ),
+			array( 'term_id' => $terms[0] )
+		);
+
+		$q = new WP_Term_Query( array(
+			'term_taxonomy_id' => 12345,
+			'fields' => 'ids',
+			'hide_empty' => false,
+		) );
+
+		$this->assertEqualSets( array( $terms[0] ), $q->terms );
+	}
+
+	/**
+	 * @ticket 37074
+	 */
+	public function test_term_taxonomy_id_array() {
+		global $wpdb;
+
+		register_taxonomy( 'wptests_tax', 'post' );
+
+		$terms = self::factory()->term->create_many( 3, array( 'taxonomy' => 'wptests_tax' ) );
+
+		// Manually change the term_taxonomy_id to something else.
+		$wpdb->update(
+			$wpdb->term_taxonomy,
+			array( 'term_taxonomy_id' => 12345 ),
+			array( 'term_id' => $terms[0] )
+		);
+
+		$wpdb->update(
+			$wpdb->term_taxonomy,
+			array( 'term_taxonomy_id' => 6789 ),
+			array( 'term_id' => $terms[2] )
+		);
+
+		$q = new WP_Term_Query( array(
+			'term_taxonomy_id' => array( 12345, 6789 ),
+			'fields' => 'ids',
+			'hide_empty' => false,
+		) );
+
+		$this->assertEqualSets( array( $terms[0], $terms[2] ), $q->terms );
+	}
+}