From 65e057daa25fdaed35dc7dd3d0642b112334f383 Mon Sep 17 00:00:00 2001
From: Gary Pendergast <pento@git.wordpress.org>
Date: Mon, 8 Apr 2019 01:09:01 +0000
Subject: [PATCH] Canonical: Ensure redirect query keys are URL encoded.

This prevents an infinite redirect loop when a request containing URL-encoded characters triggers `is_404()`.

Props soulseekah, wrwrwr0.
Fixes #43745.


git-svn-id: https://develop.svn.wordpress.org/trunk@45133 602fd350-edb4-49c9-b593-d223f7449a82
---
 src/wp-includes/canonical.php     |  5 ++++-
 tests/phpunit/tests/canonical.php | 20 ++++++++++++++++++++
 2 files changed, 24 insertions(+), 1 deletion(-)

diff --git a/src/wp-includes/canonical.php b/src/wp-includes/canonical.php
index 36ff32053b..3bf9b452a7 100644
--- a/src/wp-includes/canonical.php
+++ b/src/wp-includes/canonical.php
@@ -388,7 +388,10 @@ function redirect_canonical( $requested_url = null, $do_redirect = true ) {
 			}
 		}
 
-		$_parsed_query = rawurlencode_deep( $_parsed_query );
+		$_parsed_query = array_combine(
+			rawurlencode_deep( array_keys( $_parsed_query ) ),
+			rawurlencode_deep( array_values( $_parsed_query ) )
+		);
 		$redirect_url  = add_query_arg( $_parsed_query, $redirect_url );
 	}
 
diff --git a/tests/phpunit/tests/canonical.php b/tests/phpunit/tests/canonical.php
index a2bbc0636a..53d666e59c 100644
--- a/tests/phpunit/tests/canonical.php
+++ b/tests/phpunit/tests/canonical.php
@@ -213,4 +213,24 @@ class Tests_Canonical extends WP_Canonical_UnitTestCase {
 			// Todo: Endpoints (feeds, trackbacks, etc), More fuzzed mixed query variables, comment paging, Home page (Static)
 		);
 	}
+
+	/**
+	 * @ticket 43745
+	 */
+	public function test_utf8_query_keys_canonical() {
+		$p = self::factory()->post->create(
+			array(
+				'post_type' => 'page',
+			)
+		);
+		update_option( 'show_on_front', 'page' );
+		update_option( 'page_on_front', $p );
+
+		$this->go_to( get_permalink( $p ) );
+
+		$url = redirect_canonical( add_query_arg( '%D0%BA%D0%BE%D0%BA%D0%BE%D0%BA%D0%BE', 1, site_url( '/' ) ), false );
+		$this->assertNull( $url );
+
+		delete_option( 'page_on_front' );
+	}
 }