Index: menu-header.php
===================================================================
--- menu-header.php	(revision 46888)
+++ menu-header.php	(working copy)
@@ -88,7 +88,7 @@
 			$submenu_items = $submenu[ $item[2] ];
 		}
 
-		if ( ( $parent_file && $item[2] == $parent_file ) || ( empty( $typenow ) && $self == $item[2] ) ) {
+		if ( ( $parent_file && $item[2] === $parent_file ) || ( empty( $typenow ) && $self === $item[2] ) ) {
 			if ( ! empty( $submenu_items ) ) {
 				$class[] = 'wp-has-current-submenu wp-menu-open';
 			} else {
@@ -157,7 +157,7 @@
 			if ( false !== $pos ) {
 				$menu_file = substr( $menu_file, 0, $pos );
 			}
-			if ( ! empty( $menu_hook ) || ( ( 'index.php' != $submenu_items[0][2] ) && file_exists( WP_PLUGIN_DIR . "/$menu_file" ) && ! file_exists( ABSPATH . "/wp-admin/$menu_file" ) ) ) {
+			if ( ! empty( $menu_hook ) || ( ( 'index.php' !== $submenu_items[0][2] ) && file_exists( WP_PLUGIN_DIR . "/$menu_file" ) && ! file_exists( ABSPATH . "/wp-admin/$menu_file" ) ) ) {
 				$admin_is_parent = true;
 				echo "<a href='admin.php?page={$submenu_items[0][2]}'$class $aria_attributes>$arrow<div class='wp-menu-image$img_class'$img_style>$img</div><div class='wp-menu-name'>$title</div></a>";
 			} else {
@@ -170,7 +170,7 @@
 			if ( false !== $pos ) {
 				$menu_file = substr( $menu_file, 0, $pos );
 			}
-			if ( ! empty( $menu_hook ) || ( ( 'index.php' != $item[2] ) && file_exists( WP_PLUGIN_DIR . "/$menu_file" ) && ! file_exists( ABSPATH . "/wp-admin/$menu_file" ) ) ) {
+			if ( ! empty( $menu_hook ) || ( ( 'index.php' !== $item[2] ) && file_exists( WP_PLUGIN_DIR . "/$menu_file" ) && ! file_exists( ABSPATH . "/wp-admin/$menu_file" ) ) ) {
 				$admin_is_parent = true;
 				echo "\n\t<a href='admin.php?page={$item[2]}'$class $aria_attributes>$arrow<div class='wp-menu-image$img_class'$img_style>$img</div><div class='wp-menu-name'>{$item[0]}</div></a>";
 			} else {
@@ -208,7 +208,7 @@
 				$self_type = ! empty( $typenow ) ? $self . '?post_type=' . $typenow : 'nothing';
 
 				if ( isset( $submenu_file ) ) {
-					if ( $submenu_file == $sub_item[2] ) {
+					if ( $submenu_file === $sub_item[2] ) {
 						$class[]          = 'current';
 						$aria_attributes .= ' aria-current="page"';
 					}
@@ -215,8 +215,8 @@
 					// If plugin_page is set the parent must either match the current page or not physically exist.
 					// This allows plugin pages with the same hook to exist under different parents.
 				} elseif (
-					( ! isset( $plugin_page ) && $self == $sub_item[2] ) ||
-					( isset( $plugin_page ) && $plugin_page == $sub_item[2] && ( $item[2] == $self_type || $item[2] == $self || file_exists( $menu_file ) === false ) )
+					( ! isset( $plugin_page ) && $self === $sub_item[2] ) ||
+					( isset( $plugin_page ) && $plugin_page === $sub_item[2] && ( $item[2] === $self_type || $item[2] === $self || file_exists( $menu_file ) === false ) )
 				) {
 					$class[]          = 'current';
 					$aria_attributes .= ' aria-current="page"';
@@ -237,7 +237,7 @@
 
 				$title = wptexturize( $sub_item[0] );
 
-				if ( ! empty( $menu_hook ) || ( ( 'index.php' != $sub_item[2] ) && file_exists( WP_PLUGIN_DIR . "/$sub_file" ) && ! file_exists( ABSPATH . "/wp-admin/$sub_file" ) ) ) {
+				if ( ! empty( $menu_hook ) || ( ( 'index.php' !== $sub_item[2] ) && file_exists( WP_PLUGIN_DIR . "/$sub_file" ) && ! file_exists( ABSPATH . "/wp-admin/$sub_file" ) ) ) {
 					// If admin.php is the current page or if the parent exists as a file in the plugins or admin dir
 					if ( ( ! $admin_is_parent && file_exists( WP_PLUGIN_DIR . "/$menu_file" ) && ! is_dir( WP_PLUGIN_DIR . "/{$item[2]}" ) ) || file_exists( $menu_file ) ) {
 						$sub_item_url = add_query_arg( array( 'page' => $sub_item[2] ), $item[2] );