Ticket #35076: 35076.3.patch

src/wp-admin/includes/post.php

@@ -1380 +1380 @@
 
         $post               = get_post( $post );
         $post_type_object   = get_post_type_object( $post->post_type );
-        $set_thumbnail_link = '<p class="hide-if-no-js"><a href="%s" id="set-post-thumbnail" aria-describedby="set-post-thumbnail-desc" class="thickbox">%s</a></p>';
+        $set_thumbnail_link = '<p class="hide-if-no-js"><a href="%s" id="set-post-thumbnail"%s class="thickbox">%s</a></p>';
         $upload_iframe_src  = get_upload_iframe_src( 'image', $post->ID );
 
         $content = sprintf( $set_thumbnail_link,
                 esc_url( $upload_iframe_src ),
+                '', // Empty when there's no featured image set, `aria-describedby` attribute otherwise.
                 esc_html( $post_type_object->labels->set_featured_image )
         );
 
@@ -1416 +1417 @@
                         $ajax_nonce = wp_create_nonce( 'set_post_thumbnail-' . $post->ID );
                         $content = sprintf( $set_thumbnail_link,
                                 esc_url( $upload_iframe_src ),
+                                ' aria-describedby="set-post-thumbnail-desc"',
                                 $thumbnail_html
                         );
                         $content .= '<p class="hide-if-no-js howto" id="set-post-thumbnail-desc">' . __( 'Click the image to edit or update' ) . '</p>';