Media: avoid "divide by zero" in `wp_get_attachment_image_srcset_array()`.

Fixes #34238.

Built from https://develop.svn.wordpress.org/trunk@35081


git-svn-id: http://core.svn.wordpress.org/trunk@35046 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/media.php

@@ -921,7 +921,11 @@ function wp_get_attachment_image_srcset_array( $attachment_id, $size = 'medium'
 		$candidate_url = path_join( dirname( $img_url ), $img['file'] );
 
 		// Calculate the new image ratio.
+		if ( $img['width'] ) {
 			$img_ratio_compare = $img['height'] / $img['width'];
+		} else {
+			$img_ratio_compare = 0;
+		}
 
 		// If the new ratio differs by less than 0.01, use it.
 		if ( abs( $img_ratio - $img_ratio_compare ) < 0.01 && ! in_array( $candidate_url, $candidates ) ) {

wp-includes/version.php

@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '4.4-alpha-35080';
+$wp_version = '4.4-alpha-35081';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.