Index: wp-admin/includes/update.php
===================================================================
--- wp-admin/includes/update.php	(revision 23132)
+++ wp-admin/includes/update.php	(working copy)
@@ -32,24 +32,27 @@
 function get_core_updates( $options = array() ) {
 	$options = array_merge( array('available' => true, 'dismissed' => false ), $options );
 	$dismissed = get_site_option( 'dismissed_update_core' );
-	if ( !is_array( $dismissed ) ) $dismissed = array();
+
+	if ( !is_array( $dismissed ) )
+		$dismissed = array();
+
 	$from_api = get_site_transient( 'update_core' );
-	if ( empty($from_api) )
+
+	if ( !isset( $from_api->updates ) || !is_array( $from_api->updates ) )
 		return false;
-	if ( !isset( $from_api->updates ) || !is_array( $from_api->updates ) ) return false;
+
 	$updates = $from_api->updates;
-	if ( !is_array( $updates ) ) return false;
 	$result = array();
-	foreach($updates as $update) {
-		if ( array_key_exists( $update->current.'|'.$update->locale, $dismissed ) ) {
+	foreach ( $updates as $update ) {
+		if ( array_key_exists( $update->current . '|' . $update->locale, $dismissed ) ) {
 			if ( $options['dismissed'] ) {
 				$update->dismissed = true;
-				$result[]= $update;
+				$result[] = $update;
 			}
 		} else {
 			if ( $options['available'] ) {
 				$update->dismissed = false;
-				$result[]= $update;
+				$result[] = $update;
 			}
 		}
 	}
@@ -58,23 +61,29 @@
 
 function dismiss_core_update( $update ) {
 	$dismissed = get_site_option( 'dismissed_update_core' );
-	$dismissed[ $update->current.'|'.$update->locale ] = true;
+	$dismissed[ $update->current . '|' . $update->locale ] = true;
 	return update_site_option( 'dismissed_update_core', $dismissed );
 }
 
 function undismiss_core_update( $version, $locale ) {
 	$dismissed = get_site_option( 'dismissed_update_core' );
-	$key = $version.'|'.$locale;
-	if ( !isset( $dismissed[$key] ) ) return false;
+	$key = $version . '|' . $locale;
+
+	if ( !isset( $dismissed[$key] ) )
+		return false;
+
 	unset( $dismissed[$key] );
 	return update_site_option( 'dismissed_update_core', $dismissed );
 }
 
 function find_core_update( $version, $locale ) {
 	$from_api = get_site_transient( 'update_core' );
-	if ( !is_array( $from_api->updates ) ) return false;
+
+	if ( !isset( $from_api->updates ) || !is_array( $from_api->updates ) )
+		return false;
+
 	$updates = $from_api->updates;
-	foreach($updates as $update) {
+	foreach ( $updates as $update ) {
 		if ( $update->current == $version && $update->locale == $locale )
 			return $update;
 	}