Index: install.php
===================================================================
--- install.php	(revision 46888)
+++ install.php	(working copy)
@@ -92,7 +92,7 @@
 	global $wpdb;
 
 	$sql        = $wpdb->prepare( 'SHOW TABLES LIKE %s', $wpdb->esc_like( $wpdb->users ) );
-	$user_table = ( $wpdb->get_var( $sql ) != null );
+	$user_table = ( $wpdb->get_var( $sql ) !== null );
 
 	// Ensure that Blogs appear in search engines by default.
 	$blog_public = 1;
@@ -369,10 +369,10 @@
 			// TODO: poka-yoke
 			display_setup_form( __( 'Please provide a valid username.' ) );
 			$error = true;
-		} elseif ( $user_name != sanitize_user( $user_name, true ) ) {
+		} elseif ( $user_name !== sanitize_user( $user_name, true ) ) {
 			display_setup_form( __( 'The username you provided has invalid characters.' ) );
 			$error = true;
-		} elseif ( $admin_password != $admin_password_check ) {
+		} elseif ( $admin_password !== $admin_password_check ) {
 			// TODO: poka-yoke
 			display_setup_form( __( 'Your passwords do not match. Please try again.' ) );
 			$error = true;