From 3a7b5748eb1e9a29856cf52d0f941168d73d535b Mon Sep 17 00:00:00 2001
From: Jeremy Felt <jeremy.felt@gmail.com>
Date: Thu, 20 Nov 2014 06:53:22 +0000
Subject: [PATCH] Prevent wpmu_delete_blog from removing the wrong uploads
 directory

`wp_upload_dir()` includes some logic to fall back to the default site's upload directory if a specific directory for the requested site cannot be found. Because of this, if `wpmu_delete_blog()` is fired twice in a row for the same site, the main site's upload directory could be deleted as well.

This adds some checks in `wpmu_delete_blog()` so that we are confident in the site and it's upload directory's existence before dropping the site. Tests are added for when `ms_files_rewriting` is enabled or disabled.

Fixes #30121

Built from https://develop.svn.wordpress.org/trunk@30404


git-svn-id: http://core.svn.wordpress.org/trunk@30399 1a063a9b-81f0-0310-95a4-ce76da25c4cd
---
 wp-admin/includes/ms.php | 20 +++++++++++++++++---
 1 file changed, 17 insertions(+), 3 deletions(-)

diff --git a/wp-admin/includes/ms.php b/wp-admin/includes/ms.php
index d2201d34ba..4735cf97fc 100644
--- a/wp-admin/includes/ms.php
+++ b/wp-admin/includes/ms.php
@@ -85,11 +85,26 @@ function wpmu_delete_blog( $blog_id, $drop = false ) {
 
 	$current_site = get_current_site();
 
-	// Don't destroy the initial, main, or root blog.
-	if ( $drop && ( 1 == $blog_id || is_main_site( $blog_id ) || ( $blog->path == $current_site->path && $blog->domain == $current_site->domain ) ) )
+	// If a full blog object is not available, do not destroy anything.
+	if ( $drop && ! $blog ) {
 		$drop = false;
+	}
+
+	// Don't destroy the initial, main, or root blog.
+	if ( $drop && ( 1 == $blog_id || is_main_site( $blog_id ) || ( $blog->path == $current_site->path && $blog->domain == $current_site->domain ) ) ) {
+		$drop = false;
+	}
+
+	$upload_path = trim( get_option( 'upload_path' ) );
+
+	// If ms_files_rewriting is enabled and upload_path is empty, wp_upload_dir is not reliable.
+	if ( $drop && get_site_option( 'ms_files_rewriting' ) && empty( $upload_path ) ) {
+		$drop = false;
+	}
 
 	if ( $drop ) {
+		$uploads = wp_upload_dir();
+
 		$tables = $wpdb->tables( 'blog' );
 		/**
 		 * Filter the tables to drop when the blog is deleted.
@@ -107,7 +122,6 @@ function wpmu_delete_blog( $blog_id, $drop = false ) {
 
 		$wpdb->delete( $wpdb->blogs, array( 'blog_id' => $blog_id ) );
 
-		$uploads = wp_upload_dir();
 		/**
 		 * Filter the upload base directory to delete when the blog is deleted.
 		 *