From eadc17c4f9e059fd5a838f2567009e5d25f52edc Mon Sep 17 00:00:00 2001
From: Scott Taylor <wonderboymusic@git.wordpress.org>
Date: Wed, 11 Jun 2014 02:27:36 +0000
Subject: [PATCH] In `wp_insert_term()`, when no slug is provided, check for an
 existing term by name. If it exists, use that slug instead of calling
 `sanitize_title( $name )`.

Prevents creating an endless number of terms like `A+` or `$$$$` in any given taxonomy.

Props wonderboymusic, SergeyBiryukov, aaroncampbell.
Fixes #17689.


git-svn-id: https://develop.svn.wordpress.org/trunk@28733 602fd350-edb4-49c9-b593-d223f7449a82
---
 src/wp-includes/taxonomy.php     |  8 ++++-
 tests/phpunit/tests/taxonomy.php | 62 ++++++++++++++++++++++++++++++++
 2 files changed, 69 insertions(+), 1 deletion(-)

diff --git a/src/wp-includes/taxonomy.php b/src/wp-includes/taxonomy.php
index ae0ef81dd3..1c48934ae9 100644
--- a/src/wp-includes/taxonomy.php
+++ b/src/wp-includes/taxonomy.php
@@ -2436,7 +2436,13 @@ function wp_insert_term( $term, $taxonomy, $args = array() ) {
 
 	$slug_provided = ! empty( $args['slug'] );
 	if ( ! $slug_provided ) {
-		$slug = sanitize_title($name);
+		$_name = trim( $name );
+		$existing_term = get_term_by( 'name', $_name, $taxonomy );
+		if ( $existing_term ) {
+			$slug = $existing_term->slug;
+		} else {
+			$slug = sanitize_title( $name );
+		}
 	} else {
 		$slug = $args['slug'];
 	}
diff --git a/tests/phpunit/tests/taxonomy.php b/tests/phpunit/tests/taxonomy.php
index 979cca14b8..7d5bff4588 100644
--- a/tests/phpunit/tests/taxonomy.php
+++ b/tests/phpunit/tests/taxonomy.php
@@ -232,4 +232,66 @@ class Tests_Taxonomy extends WP_UnitTestCase {
 		);
 		$this->assertEquals( 0, wp_insert_category( $cat, false ) );
 	}
+
+	/**
+	 * @ticket 17689
+	 */
+	function test_duplicate_name() {
+		$term = $this->factory->tag->create_and_get( array( 'name' => 'Bozo' ) );
+		$this->assertFalse( is_wp_error( $term ) );
+		$this->assertTrue( empty( $term->errors ) );
+
+		// Test existing term name with unique slug
+		$term1 = $this->factory->tag->create( array( 'name' => 'Bozo', 'slug' => 'bozo1' ) );
+		$this->assertFalse( is_wp_error( $term1 ) );
+		$this->assertTrue( empty($term1->errors ) );
+
+		// Test an existing term name
+		$term2 = $this->factory->tag->create( array( 'name' => 'Bozo' ) );
+		$this->assertTrue( is_wp_error( $term2 ) );
+		$this->assertNotEmpty( $term2->errors );
+
+		// Test named terms ending in special characters
+		$term3 = $this->factory->tag->create( array( 'name' => 'T$' ) );
+		$term4 = $this->factory->tag->create( array( 'name' => 'T$$' ) );
+		$term5 = $this->factory->tag->create( array( 'name' => 'T$$$' ) );
+		$term6 = $this->factory->tag->create( array( 'name' => 'T$$$$' ) );
+		$term7 = $this->factory->tag->create( array( 'name' => 'T$$$$' ) );
+		$this->assertTrue( is_wp_error( $term7 ) );
+		$this->assertNotEmpty( $term7->errors );
+		$this->assertEquals( $term6, $term7->error_data['term_exists'] );
+
+		$terms = array_map( 'get_tag', array( $term3, $term4, $term5, $term6 ) );
+		$this->assertCount( 4, array_unique( wp_list_pluck( $terms, 'slug' ) ) );
+
+		// Test named terms with only special characters
+		$term8 = $this->factory->tag->create( array( 'name' => '$' ) );
+		$term9 = $this->factory->tag->create( array( 'name' => '$$' ) );
+		$term10 = $this->factory->tag->create( array( 'name' => '$$$' ) );
+		$term11 = $this->factory->tag->create( array( 'name' => '$$$$' ) );
+		$term12 = $this->factory->tag->create( array( 'name' => '$$$$' ) );
+		$this->assertTrue( is_wp_error( $term12 ) );
+		$this->assertNotEmpty( $term12->errors );
+		$this->assertEquals( $term11, $term12->error_data['term_exists'] );
+
+		$terms = array_map( 'get_tag', array( $term8, $term9, $term10, $term11 ) );
+		$this->assertCount( 4, array_unique( wp_list_pluck( $terms, 'slug' ) ) );
+
+		$term13 = $this->factory->tag->create( array( 'name' => 'A' ) );
+		$this->assertFalse( is_wp_error( $term13 ) );
+		$term14 = $this->factory->tag->create( array( 'name' => 'A' ) );
+		$this->assertTrue( is_wp_error( $term14 ) );
+		$term15 = $this->factory->tag->create( array( 'name' => 'A+', 'slug' => 'a' ) );
+		$this->assertFalse( is_wp_error( $term15 ) );
+		$term16 = $this->factory->tag->create( array( 'name' => 'A+' ) );
+		$this->assertTrue( is_wp_error( $term16 ) );
+		$term17 = $this->factory->tag->create( array( 'name' => 'A++' ) );
+		$this->assertFalse( is_wp_error( $term17 ) );
+		$term18 = $this->factory->tag->create( array( 'name' => 'A-', 'slug' => 'a' ) );
+		$this->assertFalse( is_wp_error( $term18 ) );
+		$term19 = $this->factory->tag->create( array( 'name' => 'A-' ) );
+		$this->assertTrue( is_wp_error( $term19 ) );
+		$term20 = $this->factory->tag->create( array( 'name' => 'A--' ) );
+		$this->assertFalse( is_wp_error( $term20 ) );
+	}
 }