Embeds: Fix get_site_icon_url() dropping fallback when attachment URL fails

Author: Sukhendu2002

src/wp-includes/embed.php

@@ -1233,11 +1233,23 @@ function print_embed_sharing_dialog() {
  * @since 4.5.0
  */
 function the_embed_site_title() {
+	$site_icon_url    = get_site_icon_url( 32, includes_url( 'images/w-logo-blue.png' ) );
+	$site_icon_url_2x = get_site_icon_url( 64, includes_url( 'images/w-logo-blue.png' ) );
+
+	$icon_img = '';
+	if ( $site_icon_url ) {
+		$srcset   = $site_icon_url_2x ? sprintf( ' srcset="%s 2x"', esc_url( $site_icon_url_2x ) ) : '';
+		$icon_img = sprintf(
+			'<img src="%s"%s width="32" height="32" alt="" class="wp-embed-site-icon" />',
+			esc_url( $site_icon_url ),
+			$srcset
+		);
+	}
+
 	$site_title = sprintf(
-		'<a href="%s" target="_top"><img src="%s" srcset="%s 2x" width="32" height="32" alt="" class="wp-embed-site-icon" /><span>%s</span></a>',
+		'<a href="%s" target="_top">%s<span>%s</span></a>',
 		esc_url( home_url() ),
-		esc_url( get_site_icon_url( 32, includes_url( 'images/w-logo-blue.png' ) ) ),
-		esc_url( get_site_icon_url( 64, includes_url( 'images/w-logo-blue.png' ) ) ),
+		$icon_img,
 		esc_html( get_bloginfo( 'name' ) )
 	);
 

src/wp-includes/general-template.php

@@ -978,7 +978,10 @@ function get_site_icon_url( $size = 512, $url = '', $blog_id = 0 ) {
 		} else {
 			$size_data = array( $size, $size );
 		}
-		$url = wp_get_attachment_image_url( $site_icon_id, $size_data );
+		$attachment_url = wp_get_attachment_image_url( $site_icon_id, $size_data );
+		if ( $attachment_url ) {
+			$url = $attachment_url;
+		}
 	}
 
 	if ( $switched_blog ) {