From 576f78ac495d5c23b4007285316eeed4930f02c3 Mon Sep 17 00:00:00 2001
From: Boone Gorges <boonebgorges@git.wordpress.org>
Date: Mon, 20 Nov 2017 22:45:29 +0000
Subject: [PATCH] Improve data types returned from empty hierarchical term
 queries.

When querying for 'count', ensure that 0 is returned. Otherwise,
ensure that it's an array.

Props xParham, birgire.
Fixes #42327.

git-svn-id: https://develop.svn.wordpress.org/trunk@42209 602fd350-edb4-49c9-b593-d223f7449a82
---
 src/wp-includes/class-wp-term-query.php |  7 ++-
 tests/phpunit/tests/term/query.php      | 67 +++++++++++++++++++++++++
 2 files changed, 73 insertions(+), 1 deletion(-)

diff --git a/src/wp-includes/class-wp-term-query.php b/src/wp-includes/class-wp-term-query.php
index d704f5e161..e27b68676b 100644
--- a/src/wp-includes/class-wp-term-query.php
+++ b/src/wp-includes/class-wp-term-query.php
@@ -379,7 +379,12 @@ class WP_Term_Query {
 			}
 
 			if ( ! $in_hierarchy ) {
-				return array();
+				if ( 'count' == $args['fields'] ) {
+					return 0;
+				} else {
+					$this->terms = array();
+					return $this->terms;
+				}
 			}
 		}
 
diff --git a/tests/phpunit/tests/term/query.php b/tests/phpunit/tests/term/query.php
index 117befadd3..a3c6c0e817 100644
--- a/tests/phpunit/tests/term/query.php
+++ b/tests/phpunit/tests/term/query.php
@@ -471,4 +471,71 @@ class Tests_Term_Query extends WP_UnitTestCase {
 		$this->assertSame( $expected, $found2 );
 		$this->assertSame( $expected, $found3 );
 	}
+
+	/**
+	 * The query method should return zero for field as count and parent set.
+	 *
+	 * @ticket 42327
+	 */
+	public function test_query_should_return_zero_for_field_count_and_parent_set() {
+		$post_id = self::factory()->post->create();
+		register_taxonomy( 'wptests_tax', 'post' );
+
+		$term_id = self::factory()->term->create( array(
+			'taxonomy' => 'wptests_tax',
+		) );
+		wp_set_object_terms( $post_id, array( $term_id ), 'wptests_tax' );
+
+		$q = new WP_Term_Query();
+		$args = array(
+			'taxonomy' => 'wptests_tax',
+			'parent'   => $term_id,
+			'fields'   => 'count',
+		);
+		$this->assertSame( 0, $q->query( $args ) );
+	}
+
+	/**
+	 * The query method should return zero for field as count and child_of set.
+	 *
+	 * @ticket 42327
+	 */
+	public function test_query_should_return_zero_for_field_as_count_and_child_of_set() {
+		$post_id = self::factory()->post->create();
+		register_taxonomy( 'wptests_tax', 'post' );
+
+		$term_id = self::factory()->term->create( array(
+			'taxonomy' => 'wptests_tax',
+		) );
+		wp_set_object_terms( $post_id, array( $term_id ), 'wptests_tax' );
+
+		$q = new WP_Term_Query();
+		$args = array(
+			'taxonomy' => 'wptests_tax',
+			'child_of' => $term_id,
+			'fields'   => 'count',
+		);
+		$this->assertSame( 0, $q->query( $args ) );
+	}
+
+	/**
+	 * The terms property should be an empty array for fields not as count and parent set.
+	 *
+	 * @ticket 42327
+	 */
+	public function test_terms_property_should_be_empty_array_for_field_not_as_count_and_parent_set() {
+		$post_id = self::factory()->post->create();
+		register_taxonomy( 'wptests_tax', 'post' );
+
+		$term_id = self::factory()->term->create( array(
+			'taxonomy' => 'wptests_tax',
+		) );
+		wp_set_object_terms( $post_id, array( $term_id ), 'wptests_tax' );
+
+		$q = new WP_Term_Query( array(
+			'taxonomy' => 'wptests_tax',
+			'parent'   => $term_id,
+		) );
+		$this->assertSame( array(), $q->terms );
+	}
 }