From e9ef25d9f6189af27891d2dd937665bbda284bc1 Mon Sep 17 00:00:00 2001
From: Boone Gorges <boonebgorges@git.wordpress.org>
Date: Fri, 14 Oct 2016 20:05:40 +0000
Subject: [PATCH] Query: Allow the hyphen-prefix-for-search-exclusion feature
 to be disabled by filter.

WordPress 4.4 introduced "hyphen exclusion" for search terms, so that
"foo -bar" would return posts containing "foo" AND not containing "bar".
The new filter 'wp_query_use_hyphen_for_exclusion' allows developers
to disable this feature when it's known that their content will contain
semantically important leading hyphens.

Props chriseverson, choongsavvii.
Fixes #38099.

git-svn-id: https://develop.svn.wordpress.org/trunk@38792 602fd350-edb4-49c9-b593-d223f7449a82
---
 src/wp-includes/class-wp-query.php   | 16 ++++++++++++++--
 tests/phpunit/tests/query/search.php | 22 ++++++++++++++++++++++
 2 files changed, 36 insertions(+), 2 deletions(-)

diff --git a/src/wp-includes/class-wp-query.php b/src/wp-includes/class-wp-query.php
index 226170ee7d..9e7883f6c5 100644
--- a/src/wp-includes/class-wp-query.php
+++ b/src/wp-includes/class-wp-query.php
@@ -721,7 +721,9 @@ class WP_Query {
 	 *     @type array        $post_name__in           An array of post slugs that results must match.
 	 *     @type string       $s                       Search keyword(s). Prepending a term with a hyphen will
 	 *                                                 exclude posts matching that term. Eg, 'pillow -sofa' will
-	 *                                                 return posts containing 'pillow' but not 'sofa'.
+	 *                                                 return posts containing 'pillow' but not 'sofa'. This feature
+	 *                                                 can be disabled using the
+	 *                                                 'wp_query_use_hyphen_for_exclusion' filter.
 	 *     @type int          $second                  Second of the minute. Default empty. Accepts numbers 0-60.
 	 *     @type bool         $sentence                Whether to search by phrase. Default false.
 	 *     @type bool         $suppress_filters        Whether to suppress filters. Default false.
@@ -1318,10 +1320,20 @@ class WP_Query {
 		$n = ! empty( $q['exact'] ) ? '' : '%';
 		$searchand = '';
 		$q['search_orderby_title'] = array();
+
+		/**
+		 * Filters whether search terms preceded by hyphens should excluded from results.
+		 *
+		 * @since 4.7.0
+		 *
+		 * @param bool Whether the query should exclude terms preceded with a hyphen.
+		 */
+		$hyphen_exclusion = apply_filters( 'wp_query_use_hyphen_for_exclusion', true );
+
 		foreach ( $q['search_terms'] as $term ) {
 			// Terms prefixed with '-' should be excluded.
 			$include = '-' !== substr( $term, 0, 1 );
-			if ( $include ) {
+			if ( $include || ! $hyphen_exclusion ) {
 				$like_op  = 'LIKE';
 				$andor_op = 'OR';
 			} else {
diff --git a/tests/phpunit/tests/query/search.php b/tests/phpunit/tests/query/search.php
index 2931a1a731..43c5da4caa 100644
--- a/tests/phpunit/tests/query/search.php
+++ b/tests/phpunit/tests/query/search.php
@@ -59,6 +59,28 @@ class Tests_Query_Search extends WP_UnitTestCase {
 		return array();
 	}
 
+	/**
+	 * @ticket 38099
+	 */
+	function test_filter_wp_query_use_hyphen_for_exclusion() {
+		$title = '-HYPHENATION_TEST';
+
+		// Create a post with a title which starts with a hyphen
+		$post_id = self::factory()->post->create( array(
+			'post_content' => $title, 'post_type' => $this->post_type
+		) );
+
+		// By default, we can use the hyphen prefix to exclude results
+		$this->assertEquals( array(), $this->get_search_results( $title ) );
+
+		// After we disable the feature using the filter, we should get the result
+		add_filter( 'wp_query_use_hyphen_for_exclusion', '__return_false' );
+		$result = $this->get_search_results( $title );
+		$post = array_pop( $result );
+		$this->assertEquals( $post->ID, $post_id );
+		remove_filter( 'wp_query_use_hyphen_for_exclusion', '__return_false' );
+	}
+
 	/**
 	 * @ticket 33988
 	 */