From 8142df82bcfa9201f0bb48499f89e5d2e957697d Mon Sep 17 00:00:00 2001
From: Boone Gorges <boonebgorges@gmail.com>
Date: Wed, 15 Aug 2018 19:50:25 +0000
Subject: [PATCH] Introduce `wp_insert_term_duplicate_term_check` filter.

This filter allows plugins to intervene in the duplicate-term check
that takes place at the time of term creation. See [30238], #22023.

Props strategio.
Fixes #43271.
Built from https://develop.svn.wordpress.org/trunk@43570


git-svn-id: http://core.svn.wordpress.org/trunk@43399 1a063a9b-81f0-0310-95a4-ce76da25c4cd
---
 wp-includes/taxonomy.php | 21 ++++++++++++++++++++-
 wp-includes/version.php  |  2 +-
 2 files changed, 21 insertions(+), 2 deletions(-)

diff --git a/wp-includes/taxonomy.php b/wp-includes/taxonomy.php
index 8ec3eaee3e..00c57947be 100644
--- a/wp-includes/taxonomy.php
+++ b/wp-includes/taxonomy.php
@@ -2312,7 +2312,26 @@ function wp_insert_term( $term, $taxonomy, $args = array() ) {
 	 * and term_taxonomy_id of the older term instead. Then return out of the function so that the "create" hooks
 	 * are not fired.
 	 */
-	$duplicate_term = $wpdb->get_row( $wpdb->prepare( "SELECT t.term_id, tt.term_taxonomy_id FROM $wpdb->terms t INNER JOIN $wpdb->term_taxonomy tt ON ( tt.term_id = t.term_id ) WHERE t.slug = %s AND tt.parent = %d AND tt.taxonomy = %s AND t.term_id < %d AND tt.term_taxonomy_id != %d", $slug, $parent, $taxonomy, $term_id, $tt_id ) );
+	$duplicate_term = $wpdb->get_row( $wpdb->prepare( "SELECT t.term_id, t.slug, tt.term_taxonomy_id, tt.taxonomy FROM $wpdb->terms t INNER JOIN $wpdb->term_taxonomy tt ON ( tt.term_id = t.term_id ) WHERE t.slug = %s AND tt.parent = %d AND tt.taxonomy = %s AND t.term_id < %d AND tt.term_taxonomy_id != %d", $slug, $parent, $taxonomy, $term_id, $tt_id ) );
+
+	/**
+	 * Filters the duplicate term check that takes place during term creation.
+	 *
+	 * Term parent+taxonomy+slug combinations are meant to be unique, and wp_insert_term()
+	 * performs a last-minute confirmation of this uniqueness before allowing a new term
+	 * to be created. Plugins with different uniqueness requirements may use this filter
+	 * to bypass or modify the duplicate-term check.
+	 *
+	 * @since 5.0.0
+	 *
+	 * @param object $duplicate_term Duplicate term row from terms table, if found.
+	 * @param string $term           Term being inserted.
+	 * @param string $taxonomy       Taxonomy name.
+	 * @param array  $args           Term arguments passed to the function.
+	 * @param int    $tt_id          term_taxonomy_id for the newly created term.
+	 */
+	$duplicate_term = apply_filters( 'wp_insert_term_duplicate_term_check', $duplicate_term, $term, $taxonomy, $args, $tt_id );
+
 	if ( $duplicate_term ) {
 		$wpdb->delete( $wpdb->terms, array( 'term_id' => $term_id ) );
 		$wpdb->delete( $wpdb->term_taxonomy, array( 'term_taxonomy_id' => $tt_id ) );
diff --git a/wp-includes/version.php b/wp-includes/version.php
index 1715300b40..88e63f1788 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '5.0-alpha-43569';
+$wp_version = '5.0-alpha-43570';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.