From f312173db5b69740f480a52f15970ce0ef75e0b6 Mon Sep 17 00:00:00 2001
From: John Blackbourn <johnbillion@git.wordpress.org>
Date: Thu, 27 Aug 2015 20:01:37 +0000
Subject: [PATCH] Improve the efficiency of `is_user_member_of_blog()` by
 removing its use of `get_blogs_of_user()`. Adds additional tests.

Fixes #32472
Props BinaryKitten, sammybeats, johnbillion


git-svn-id: https://develop.svn.wordpress.org/trunk@33771 602fd350-edb4-49c9-b593-d223f7449a82
---
 src/wp-includes/user-functions.php     | 49 +++++++++++++++++++++++---
 tests/phpunit/tests/user.php           |  5 +++
 tests/phpunit/tests/user/multisite.php | 32 +++++++++++++++--
 3 files changed, 80 insertions(+), 6 deletions(-)

diff --git a/src/wp-includes/user-functions.php b/src/wp-includes/user-functions.php
index 894e2b210c..fb13643757 100644
--- a/src/wp-includes/user-functions.php
+++ b/src/wp-includes/user-functions.php
@@ -583,17 +583,58 @@ function get_blogs_of_user( $user_id, $all = false ) {
  * @return bool
  */
 function is_user_member_of_blog( $user_id = 0, $blog_id = 0 ) {
+	global $wpdb;
+
 	$user_id = (int) $user_id;
 	$blog_id = (int) $blog_id;
 
-	if ( empty( $user_id ) )
+	if ( empty( $user_id ) ) {
 		$user_id = get_current_user_id();
+	}
 
-	if ( empty( $blog_id ) )
+	// Technically not needed, but does save calls to get_blog_details and get_user_meta
+	// in the event that the function is called when a user isn't logged in
+	if ( empty( $user_id ) ) {
+		return false;
+	} else {
+		$user = get_userdata( $user_id );
+		if ( ! $user instanceof WP_User ) {
+			return false;
+		}
+	}
+
+	if ( ! is_multisite() ) {
+		return true;
+	}
+
+	if ( empty( $blog_id ) ) {
 		$blog_id = get_current_blog_id();
+	}
 
-	$blogs = get_blogs_of_user( $user_id );
-	return array_key_exists( $blog_id, $blogs );
+	$blog = get_blog_details( $blog_id );
+
+	if ( ! $blog || ! isset( $blog->domain ) || $blog->archived || $blog->spam || $blog->deleted ) {
+		return false;
+	}
+
+	$keys = get_user_meta( $user_id );
+	if ( empty( $keys ) ) {
+		return false;
+	}
+
+	// no underscore before capabilities in $base_capabilities_key
+	$base_capabilities_key = $wpdb->base_prefix . 'capabilities';
+	$site_capabilities_key = $wpdb->base_prefix . $blog_id . '_capabilities';
+
+	if ( isset( $keys[ $base_capabilities_key ] ) && $blog_id == 1 ) {
+		return true;
+	}
+
+	if ( isset( $keys[ $site_capabilities_key ] ) ) {
+		return true;
+	}
+
+	return false;
 }
 
 /**
diff --git a/tests/phpunit/tests/user.php b/tests/phpunit/tests/user.php
index f63d8382f7..206fe2b497 100644
--- a/tests/phpunit/tests/user.php
+++ b/tests/phpunit/tests/user.php
@@ -366,6 +366,11 @@ class Tests_User extends WP_UnitTestCase {
 	function test_is_user_member_of_blog() {
 		$old_current = get_current_user_id();
 
+		$this->assertSame( 0, $old_current );
+
+		// test for "get current user" when not logged in
+		$this->assertFalse( is_user_member_of_blog() );
+
 		$user_id = $this->factory->user->create( array( 'role' => 'subscriber' ) );
 		wp_set_current_user( $user_id );
 
diff --git a/tests/phpunit/tests/user/multisite.php b/tests/phpunit/tests/user/multisite.php
index 41b0e88666..0ae955aff8 100644
--- a/tests/phpunit/tests/user/multisite.php
+++ b/tests/phpunit/tests/user/multisite.php
@@ -141,8 +141,15 @@ class Tests_Multisite_User extends WP_UnitTestCase {
 		global $wpdb;
 
 		$user1_id = $this->factory->user->create( array( 'role' => 'administrator' ) );
+		$user2_id = $this->factory->user->create( array( 'role' => 'administrator' ) );
 
 		$old_current = get_current_user_id();
+
+		$this->assertSame( 0, $old_current );
+
+		// test for "get current user" when not logged in
+		$this->assertFalse( is_user_member_of_blog() );
+
 		wp_set_current_user( $user1_id );
 
 		$this->assertTrue( is_user_member_of_blog() );
@@ -154,15 +161,36 @@ class Tests_Multisite_User extends WP_UnitTestCase {
 		$blog_ids = $this->factory->blog->create_many( 5 );
 		foreach ( $blog_ids as $blog_id ) {
 			$this->assertInternalType( 'int', $blog_id );
+
+			// Current user gets added to new blogs
 			$this->assertTrue( is_user_member_of_blog( $user1_id, $blog_id ) );
+			// Other users should not
+			$this->assertFalse( is_user_member_of_blog( $user2_id, $blog_id ) );
+
+			switch_to_blog( $blog_id );
+
+			$this->assertTrue( is_user_member_of_blog( $user1_id ) );
+			$this->assertFalse( is_user_member_of_blog( $user2_id ) );
+
+			// Remove user 1 from blog
 			$this->assertTrue( remove_user_from_blog( $user1_id, $blog_id ) );
+
+			// Add user 2 to blog
+			$this->assertTrue( add_user_to_blog( $blog_id, $user2_id, 'subscriber' ) );
+
+			$this->assertFalse( is_user_member_of_blog( $user1_id ) );
+			$this->assertTrue( is_user_member_of_blog( $user2_id ) );
+
+			restore_current_blog();
+
 			$this->assertFalse( is_user_member_of_blog( $user1_id, $blog_id ) );
+			$this->assertTrue( is_user_member_of_blog( $user2_id, $blog_id ) );
 		}
 
 		wpmu_delete_user( $user1_id );
 		$user = new WP_User( $user1_id );
-		$this->assertFalse( $user->exists(), 'WP_User->exists' );
-		$this->assertFalse( is_user_member_of_blog( $user1_id ), 'is_user_member_of_blog' );
+		$this->assertFalse( $user->exists() );
+		$this->assertFalse( is_user_member_of_blog( $user1_id ) );
 
 		wp_set_current_user( $old_current );
 	}