Themes: Avoid a PHP 7.2 warning in get_theme_roots() when $wp_theme_directories is an uncountable value.

SergeyBiryukov · SergeyBiryukov · commit 1edae38fde5a · 2018-04-30T04:54:54.000Z
See [41174] for `wp_get_themes()` and `get_raw_theme_root()`. Props burlingtonbytes, teddytime, lbenicio, desrosj. Merges [43039] to the 4.9 branch. Fixes #43374. See #40109. git-svn-id: https://develop.svn.wordpress.org/branches/4.9@43040 602fd350-edb4-49c9-b593-d223f7449a82
diff --git a/src/wp-includes/theme.php b/src/wp-includes/theme.php
@@ -353,8 +353,9 @@ function get_template_directory_uri() {
 function get_theme_roots() {
 	global $wp_theme_directories;
 
-	if ( count($wp_theme_directories) <= 1 )
+	if ( ! is_array( $wp_theme_directories ) || count( $wp_theme_directories ) <= 1 ) {
 		return '/themes';
+	}
 
 	$theme_roots = get_site_transient( 'theme_roots' );
 	if ( false === $theme_roots ) {
