From 3e9c88d75a1d86abd70af95e6c2f1f8ac6a3cfe1 Mon Sep 17 00:00:00 2001
From: Boone Gorges <boonebgorges@gmail.com>
Date: Fri, 12 Feb 2016 02:47:26 +0000
Subject: [PATCH] In `delete_metadata()`, only invalidate cache for affected
 objects.

The `$delete_all` flag in `delete_metadata()` triggers cache invalidation for
multiple objects. Previously, invalidation took place for all objects matching
the `$meta_key` parameter, regardless of whether `$meta_value` was also set.
This resulted in overly aggressive invalidation.

Props rahal.aboulfeth.
Fixes #35797.
Built from https://develop.svn.wordpress.org/trunk@36511


git-svn-id: http://core.svn.wordpress.org/trunk@36478 1a063a9b-81f0-0310-95a4-ce76da25c4cd
---
 wp-includes/meta.php    | 10 ++++++++--
 wp-includes/version.php |  2 +-
 2 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/wp-includes/meta.php b/wp-includes/meta.php
index a3cbed0b99..86cc324d4e 100644
--- a/wp-includes/meta.php
+++ b/wp-includes/meta.php
@@ -363,8 +363,14 @@ function delete_metadata($meta_type, $object_id, $meta_key, $meta_value = '', $d
 	if ( !count( $meta_ids ) )
 		return false;
 
-	if ( $delete_all )
-		$object_ids = $wpdb->get_col( $wpdb->prepare( "SELECT $type_column FROM $table WHERE meta_key = %s", $meta_key ) );
+	if ( $delete_all ) {
+		$value_clause = '';
+		if ( '' !== $meta_value && null !== $meta_value && false !== $meta_value ) {
+			$value_clause = $wpdb->prepare( " AND meta_value = %s", $meta_value );
+		}
+
+		$object_ids = $wpdb->get_col( $wpdb->prepare( "SELECT $type_column FROM $table WHERE meta_key = %s $value_clause", $meta_key ) );
+	}
 
 	/**
 	 * Fires immediately before deleting metadata of a specific type.
diff --git a/wp-includes/version.php b/wp-includes/version.php
index 7ff21ee894..88f4904a2f 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '4.5-alpha-36510';
+$wp_version = '4.5-alpha-36511';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.