Embeds: Change attachment metadata condition to prevent a warning in the embeds template.

Merge of [37452] to the 4.5 branch.

Props swissspidy.
See #35237.
Fixes #36838.
Built from https://develop.svn.wordpress.org/branches/4.5@37455


git-svn-id: http://core.svn.wordpress.org/branches/4.5@37423 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/theme-compat/embed-content.php

@@ -27,7 +27,7 @@
 		$image_size   = 'full'; // Fallback.
 
 		$meta = wp_get_attachment_metadata( $thumbnail_id );
-		if ( is_array( $meta ) ) {
+		if ( ! empty( $meta['sizes'] ) ) {
 			foreach ( $meta['sizes'] as $size => $data ) {
 				if ( $data['width'] / $data['height'] > $aspect_ratio ) {
 					$aspect_ratio = $data['width'] / $data['height'];

wp-includes/version.php

@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '4.5.3-alpha-37454';
+$wp_version = '4.5.3-alpha-37455';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.