diff --git a/wp-admin/edit.php b/wp-admin/edit.php
index dae0333465..6fea2dc9b8 100644
--- a/wp-admin/edit.php
+++ b/wp-admin/edit.php
@@ -13,12 +13,13 @@ $wp_list_table = get_list_table('WP_Posts_List_Table');
 $wp_list_table->check_permissions();
 
 // Back-compat for viewing comments of an entry
-if ( $_redirect = intval( max( @$_REQUEST['p'], @$_REQUEST['attachment_id'], @$_REQUEST['page_id'] ) ) ) {
-	wp_redirect( admin_url('edit-comments.php?p=' . $_redirect ) );
-	exit;
-} else {
-	unset( $_redirect );
+foreach ( array( 'p', 'attachment_id', 'page_id' ) as $_redirect ) {
+	if ( ! empty( $_REQUEST[ $_redirect ] ) ) {
+		wp_redirect( admin_url( 'edit-comments.php?p=' . absint( $_REQUEST[ $_redirect ] ) ) );
+		exit;
+	}
 }
+unset( $_redirect );
 
 // Handle bulk actions
 $doaction = $wp_list_table->current_action();
diff --git a/wp-admin/includes/image-edit.php b/wp-admin/includes/image-edit.php
index 3e1a6b05a0..03e7144af0 100644
--- a/wp-admin/includes/image-edit.php
+++ b/wp-admin/includes/image-edit.php
@@ -422,7 +422,7 @@ function wp_restore_image($post_id) {
 	$file = get_attached_file($post_id);
 	$backup_sizes = get_post_meta( $post_id, '_wp_attachment_backup_sizes', true );
 	$restored = false;
-	$msg = '';
+	$msg = new stdClass;
 
 	if ( !is_array($backup_sizes) ) {
 		$msg->error = __('Cannot load image metadata.');
@@ -493,7 +493,7 @@ function wp_restore_image($post_id) {
 }
 
 function wp_save_image($post_id) {
-	$return = '';
+	$return = new stdClass;
 	$success = $delete = $scaled = $nocrop = false;
 	$post = get_post($post_id);
 	@ini_set('memory_limit', '256M');
diff --git a/wp-admin/includes/user.php b/wp-admin/includes/user.php
index 6790cfe0e9..4015a02adc 100644
--- a/wp-admin/includes/user.php
+++ b/wp-admin/includes/user.php
@@ -55,14 +55,14 @@ function add_user() {
  */
 function edit_user( $user_id = 0 ) {
 	global $wp_roles, $wpdb;
-	if ( $user_id != 0 ) {
+	$user = new WP_User( $user_id );
+	if ( $user_id ) {
 		$update = true;
 		$user->ID = (int) $user_id;
 		$userdata = get_userdata( $user_id );
 		$user->user_login = $wpdb->escape( $userdata->user_login );
 	} else {
 		$update = false;
-		$user = '';
 	}
 
 	if ( !$update && isset( $_POST['user_login'] ) )
diff --git a/wp-includes/functions.php b/wp-includes/functions.php
index 632fee00f6..b01831d9bf 100644
--- a/wp-includes/functions.php
+++ b/wp-includes/functions.php
@@ -4232,7 +4232,7 @@ function get_file_data( $file, $default_headers, $context = '' ) {
 		foreach( $extra_headers as $key=>$value ) {
 			$extra_headers[$key] = $key;
 		}
-		$all_headers = array_merge($extra_headers, $default_headers);
+		$all_headers = array_merge( $extra_headers, (array) $default_headers );
 	} else {
 		$all_headers = $default_headers;
 	}