From 9cb0da37548d79e1a3f3c4adfdf239c49c464935 Mon Sep 17 00:00:00 2001
From: Sergey Biryukov <sergeybiryukov@git.wordpress.org>
Date: Thu, 17 Sep 2020 10:12:32 +0000
Subject: [PATCH] Formatting: Make sure `links_add_target()` adds the `target`
 attribute to the correct tag.

Previously, the attribute could unintentionally be added to a tag that starts with the same characters, e.g. `<aside>` instead of `<a>`.

Props antonlukin.
Fixes #51313.

git-svn-id: https://develop.svn.wordpress.org/trunk@48983 602fd350-edb4-49c9-b593-d223f7449a82
---
 src/wp-includes/formatting.php                |  2 +-
 .../tests/formatting/LinksAddTarget.php       | 24 +++++++++++++++++++
 2 files changed, 25 insertions(+), 1 deletion(-)

diff --git a/src/wp-includes/formatting.php b/src/wp-includes/formatting.php
index 45922d6f65..494c1b3e61 100644
--- a/src/wp-includes/formatting.php
+++ b/src/wp-includes/formatting.php
@@ -5243,7 +5243,7 @@ function links_add_target( $content, $target = '_blank', $tags = array( 'a' ) )
 	global $_links_add_target;
 	$_links_add_target = $target;
 	$tags              = implode( '|', (array) $tags );
-	return preg_replace_callback( "!<($tags)([^>]*)>!i", '_links_add_target', $content );
+	return preg_replace_callback( "!<($tags)((\s[^>]*)?)>!i", '_links_add_target', $content );
 }
 
 /**
diff --git a/tests/phpunit/tests/formatting/LinksAddTarget.php b/tests/phpunit/tests/formatting/LinksAddTarget.php
index f0ad0585ac..391ad1736f 100644
--- a/tests/phpunit/tests/formatting/LinksAddTarget.php
+++ b/tests/phpunit/tests/formatting/LinksAddTarget.php
@@ -64,6 +64,30 @@ class Tests_Formatting_LinksAddTarget extends WP_UnitTestCase {
 				array( 'span' ),
 				'MY CONTENT <div> SOME ADDITIONAL TEXT <a href="XYZ" src="ABC">LINK</a> HERE </div> <span src="ABC" target="_top">END TEXT</span>',
 			),
+			array(
+				'MY CONTENT <aside> SOME ADDITIONAL TEXT <a href="XYZ" src="ABC">LINK</a> HERE </aside> END TEXT',
+				null,
+				null,
+				'MY CONTENT <aside> SOME ADDITIONAL TEXT <a href="XYZ" src="ABC" target="_blank">LINK</a> HERE </aside> END TEXT',
+			),
+			array(
+				'MY CONTENT <aside class="_blank"> SOME ADDITIONAL TEXT <a href="XYZ" src="ABC">LINK</a> HERE </aside> END TEXT',
+				null,
+				null,
+				'MY CONTENT <aside class="_blank"> SOME ADDITIONAL TEXT <a href="XYZ" src="ABC" target="_blank">LINK</a> HERE </aside> END TEXT',
+			),
+			array(
+				'MY CONTENT <blockquote>SOME</blockquote> ADDITIONAL TEXT <b>LINK</b> HERE END TEXT',
+				'_blank',
+				array( 'b' ),
+				'MY CONTENT <blockquote>SOME</blockquote> ADDITIONAL TEXT <b target="_blank">LINK</b> HERE END TEXT',
+			),
+			array(
+				'MY CONTENT <blockquote target="_self">SOME</blockquote> ADDITIONAL TEXT <b>LINK</b> HERE END TEXT',
+				'_blank',
+				array( 'b' ),
+				'MY CONTENT <blockquote target="_self">SOME</blockquote> ADDITIONAL TEXT <b target="_blank">LINK</b> HERE END TEXT',
+			),
 		);
 	}