diff --git a/wp-admin/export.php b/wp-admin/export.php
index 4379dd1d4..d2a71bfd6 100644
--- a/wp-admin/export.php
+++ b/wp-admin/export.php
@@ -14,7 +14,8 @@ require_once('includes/export.php');
 $title = __('Export');
 
 if ( isset( $_GET['download'] ) ) {
-	export_wp( $_GET['author'] );
+	$author = isset($_GET['author']) ? $_GET['author'] : 'all';
+	export_wp( $author );
 	die();
 }
 
diff --git a/wp-admin/import/wordpress.php b/wp-admin/import/wordpress.php
index ce78e519a..dfed4012c 100644
--- a/wp-admin/import/wordpress.php
+++ b/wp-admin/import/wordpress.php
@@ -339,7 +339,6 @@ class WP_Import {
 	}
 
 	function process_posts() {
-		$i = -1;
 		echo '<ol>';
 
 		$this->get_entries(array(&$this, 'process_post'));
diff --git a/wp-includes/functions.php b/wp-includes/functions.php
index a24289e25..858d153cf 100644
--- a/wp-includes/functions.php
+++ b/wp-includes/functions.php
@@ -1893,7 +1893,7 @@ function wp_unique_filename( $dir, $filename, $unique_filename_callback = null )
 	$filename = strtolower( $filename );
 	// separate the filename into a name and extension
 	$info = pathinfo($filename);
-	$ext = $info['extension'];
+	$ext = !empty($info['extension']) ? $info['extension'] : '';
 	$name = basename($filename, ".{$ext}");
 
 	// edge case: if file is named '.ext', treat as an empty name
@@ -1906,9 +1906,7 @@ function wp_unique_filename( $dir, $filename, $unique_filename_callback = null )
 	} else {
 		$number = '';
 
-		if ( empty( $ext ) )
-			$ext = '';
-		else
+		if ( !empty( $ext ) )
 			$ext = strtolower( ".$ext" );
 
 		$filename = str_replace( $ext, '', $filename );
@@ -1951,11 +1949,11 @@ function wp_unique_filename( $dir, $filename, $unique_filename_callback = null )
  */
 function wp_upload_bits( $name, $deprecated, $bits, $time = null ) {
 	if ( empty( $name ) )
-		return array( 'error' => __( "Empty filename" ) );
+		return array( 'error' => __( 'Empty filename' ) );
 
 	$wp_filetype = wp_check_filetype( $name );
 	if ( !$wp_filetype['ext'] )
-		return array( 'error' => __( "Invalid file type" ) );
+		return array( 'error' => __( 'Invalid file type' ) );
 
 	$upload = wp_upload_dir( $time );