From 84207a7e8420376fc157daf324a17769b0b395b7 Mon Sep 17 00:00:00 2001
From: Andrew Ozz <azaozz@git.wordpress.org>
Date: Thu, 16 Apr 2009 21:55:35 +0000
Subject: [PATCH] Show proper error when adding a custom field without a value,
 props scohoust, fixes #7541

git-svn-id: https://develop.svn.wordpress.org/trunk@10957 602fd350-edb4-49c9-b593-d223f7449a82
---
 wp-admin/admin-ajax.php    | 10 ++++++----
 wp-admin/includes/post.php |  5 ++++-
 2 files changed, 10 insertions(+), 5 deletions(-)

diff --git a/wp-admin/admin-ajax.php b/wp-admin/admin-ajax.php
index 070285ccf7..a64813c403 100644
--- a/wp-admin/admin-ajax.php
+++ b/wp-admin/admin-ajax.php
@@ -770,7 +770,7 @@ case 'add-meta' :
 	if ( isset($_POST['metakeyselect']) || isset($_POST['metakeyinput']) ) {
 		if ( !current_user_can( 'edit_post', $pid ) )
 			die('-1');
-		if ( '#NONE#' == $_POST['metakeyselect'] && empty($_POST['metakeyinput']) )
+		if ( isset($_POST['metakeyselect']) && '#NONE#' == $_POST['metakeyselect'] && empty($_POST['metakeyinput']) )
 			die('1');
 		if ( $pid < 0 ) {
 			$now = current_time('timestamp', 1);
@@ -784,12 +784,13 @@ case 'add-meta' :
 					) );
 					$x->send();
 				}
-				$mid = add_meta( $pid );
+				if ( !$mid = add_meta( $pid ) ) 
+					die(__('Please provide a custom field value.'));
 			} else {
 				die('0');
 			}
 		} else if ( !$mid = add_meta( $pid ) ) {
-			die('0');
+			die(__('Please provide a custom field value.'));
 		}
 
 		$meta = get_post_meta_by_id( $mid );
@@ -811,7 +812,8 @@ case 'add-meta' :
 		if ( !current_user_can( 'edit_post', $meta->post_id ) )
 			die('-1');
 		if ( !$u = update_meta( $mid, $key, $value ) )
-			die('1'); // We know meta exists; we also know it's unchanged (or DB error, in which case there are bigger problems).
+			die('0'); // We know meta exists; we also know it's unchanged (or DB error, in which case there are bigger problems).
+	
 		$key = stripslashes($key);
 		$value = stripslashes($value);
 		$x = new WP_Ajax_Response( array(
diff --git a/wp-admin/includes/post.php b/wp-admin/includes/post.php
index 7f8b23c2d2..c38be1f6a6 100644
--- a/wp-admin/includes/post.php
+++ b/wp-admin/includes/post.php
@@ -677,10 +677,13 @@ function update_meta( $meta_id, $meta_key, $meta_value ) {
 	if ( in_array($meta_key, $protected) )
 		return false;
 
+	if ( '' === trim( $meta_value ) )
+		return false;
+
 	$post_id = $wpdb->get_var( $wpdb->prepare("SELECT post_id FROM $wpdb->postmeta WHERE meta_id = %d", $meta_id) );
 	wp_cache_delete($post_id, 'post_meta');
 
-	$meta_value = maybe_serialize( stripslashes( $meta_value ));
+	$meta_value = maybe_serialize( stripslashes( $meta_value ) );
 	$meta_id = (int) $meta_id;
 
 	$data  = compact( 'meta_key', 'meta_value' );