Move cap check up. Props mdawaffe. fixes #6838 for trunk

git-svn-id: http://svn.automattic.com/wordpress/trunk@7829 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-admin/media.php

@@ -9,8 +9,14 @@ wp_reset_vars(array('action'));
 
 switch( $action ) :
 case 'editattachment' :
-	$errors = media_upload_form_handler();
 	$attachment_id = (int) $_POST['attachment_id'];
+	check_admin_referer('media-form');
+
+	if ( !current_user_can('edit_post', $attachment_id) )
+		wp_die ( __('You are not allowed to edit this attachment.') );
+
+	$errors = media_upload_form_handler();
+
 
 	check_admin_referer('media-form');