From 0711e585fb745feb6caa8be20864d09442d98c57 Mon Sep 17 00:00:00 2001
From: Sergey Biryukov <sergeybiryukov@git.wordpress.org>
Date: Sun, 11 Feb 2018 15:39:20 +0000
Subject: [PATCH] Media: After [42693], update HTML4 markup in
 `img_caption_shortcode()` to avoid an empty ID attribute as well.

Add a unit test for `aria-describedby` in `img_caption_shortcode()`.

See #34595.

git-svn-id: https://develop.svn.wordpress.org/trunk@42694 602fd350-edb4-49c9-b593-d223f7449a82
---
 src/wp-includes/media.php     |  2 +-
 tests/phpunit/tests/media.php | 15 +++++++++++++++
 2 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/src/wp-includes/media.php b/src/wp-includes/media.php
index 68ac031298..55a8ad3704 100644
--- a/src/wp-includes/media.php
+++ b/src/wp-includes/media.php
@@ -1623,7 +1623,7 @@ function img_caption_shortcode( $attr, $content = null ) {
 			esc_attr( $class ),
 			str_replace( '<img ', '<img ' . $describedby, do_shortcode( $content ) ),
 			sprintf(
-				'<p id="%s" class="wp-caption-text">%s</p>',
+				'<p %sclass="wp-caption-text">%s</p>',
 				$atts['caption_id'],
 				$atts['caption']
 			)
diff --git a/tests/phpunit/tests/media.php b/tests/phpunit/tests/media.php
index 990166f91b..1fe2228aae 100644
--- a/tests/phpunit/tests/media.php
+++ b/tests/phpunit/tests/media.php
@@ -214,6 +214,21 @@ CAP;
 		$this->assertEquals( 1, preg_match_all( "~wp-caption-text.*{$content_preg}~", $result, $_r ) );
 	}
 
+	/**
+	 * @ticket 34595
+	 */
+	function test_img_caption_shortcode_has_aria_describedby() {
+		$result = img_caption_shortcode(
+			array(
+				'width' => 20,
+				'id'    => 'myId',
+			),
+			$this->img_content . $this->html_content
+		);
+
+		$this->assertEquals( 1, preg_match_all( '/aria-describedby="caption-myId"/', $result, $_r ) );
+	}
+
 	function test_add_remove_oembed_provider() {
 		wp_oembed_add_provider( 'http://foo.bar/*', 'http://foo.bar/oembed' );
 		$this->assertTrue( wp_oembed_remove_provider( 'http://foo.bar/*' ) );