From a16d16449ddee6a3c13a65fd02536a6071c04d70 Mon Sep 17 00:00:00 2001
From: Boone Gorges <boonebgorges@git.wordpress.org>
Date: Sun, 2 Jul 2017 18:28:21 +0000
Subject: [PATCH] Introduce `wp_get_object_terms_args` filter.

This filter allows developers to modify the arguments passed to
`wp_get_object_terms()` before the query is run.

Props enrico.sorcinelli.
Fixes #35925.

git-svn-id: https://develop.svn.wordpress.org/trunk@40994 602fd350-edb4-49c9-b593-d223f7449a82
---
 src/wp-includes/taxonomy.php                  | 12 ++++++++
 tests/phpunit/tests/term/wpGetObjectTerms.php | 28 +++++++++++++++++++
 2 files changed, 40 insertions(+)

diff --git a/src/wp-includes/taxonomy.php b/src/wp-includes/taxonomy.php
index eb07898507..05c6a10e8e 100644
--- a/src/wp-includes/taxonomy.php
+++ b/src/wp-includes/taxonomy.php
@@ -1882,6 +1882,18 @@ function wp_get_object_terms($object_ids, $taxonomies, $args = array()) {
 
 	$args = wp_parse_args( $args );
 
+	/**
+	 * Filter arguments for retrieving object terms.
+	 *
+	 * @since 4.9.0
+	 *
+	 * @param array        $args       An array of arguments for retrieving terms for the given object(s).
+	 *                                 See {@see wp_get_object_terms()} for details.
+	 * @param int|array    $object_ids Object ID or array of IDs.
+	 * @param string|array $taxonomies The taxonomies to retrieve terms from.
+	 */
+	$args = apply_filters( 'wp_get_object_terms_args', $args, $object_ids, $taxonomies );
+
 	/*
 	 * When one or more queried taxonomies is registered with an 'args' array,
 	 * those params override the `$args` passed to this function.
diff --git a/tests/phpunit/tests/term/wpGetObjectTerms.php b/tests/phpunit/tests/term/wpGetObjectTerms.php
index f68e4f674d..e527a601bf 100644
--- a/tests/phpunit/tests/term/wpGetObjectTerms.php
+++ b/tests/phpunit/tests/term/wpGetObjectTerms.php
@@ -732,4 +732,32 @@ class Tests_Term_WpGetObjectTerms extends WP_UnitTestCase {
 
 		$this->assertEquals( array( $t1, $t3, $t2 ), $found );
 	}
+
+	/**
+	 * @ticket 35925
+	 */
+	public function test_wp_get_object_terms_args_filter() {
+		$taxonomy = 'wptests_tax_4';
+
+		register_taxonomy( $taxonomy, 'post', array( 'sort' => 'true' ) );
+		$post_id = self::factory()->post->create();
+		$terms = array( 'foo', 'bar', 'baz' );
+		$set = wp_set_object_terms( $post_id, $terms, $taxonomy );
+
+		// Filter for maintaining term order
+		add_filter( 'wp_get_object_terms_args', array( $this, 'filter_wp_get_object_terms_args' ), 10, 3 );
+
+		// Test directly
+		$get_object_terms = wp_get_object_terms( $post_id, $taxonomy, array( 'fields' => 'names' ) );
+		$this->assertEquals( $terms, $get_object_terms );
+
+		// Test metabox taxonomy (admin advanced edit)
+		$terms_to_edit = get_terms_to_edit( $post_id, $taxonomy );
+		$this->assertEquals( implode( ',', $terms ), $terms_to_edit );
+	}
+
+	function filter_wp_get_object_terms_args ( $args, $object_ids, $taxonomies ) {
+		$args['orderby'] = 'term_order';
+		return $args;
+	}
 }