From 1d59873acee6a3b4e39a21a20e8fde96e0ccfa2c Mon Sep 17 00:00:00 2001
From: Dion Hulse <wordpress@dd32.id.au>
Date: Wed, 10 Jan 2018 06:10:47 +0000
Subject: [PATCH] Upgrade: When deleting old files, if deletion fails attempt
 to empty the file instead.

Props joemcgill, dd32.
Fixes #42963 for trunk.

Built from https://develop.svn.wordpress.org/trunk@42433


git-svn-id: http://core.svn.wordpress.org/trunk@42263 1a063a9b-81f0-0310-95a4-ce76da25c4cd
---
 wp-admin/includes/update-core.php | 6 +++++-
 wp-includes/version.php           | 2 +-
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/wp-admin/includes/update-core.php b/wp-admin/includes/update-core.php
index ec909143dd..fc6681acb3 100644
--- a/wp-admin/includes/update-core.php
+++ b/wp-admin/includes/update-core.php
@@ -1143,7 +1143,11 @@ function update_core( $from, $to ) {
 		if ( ! $wp_filesystem->exists( $old_file ) ) {
 			continue;
 		}
-		$wp_filesystem->delete( $old_file, true );
+
+		// If the file isn't deleted, try writing an empty string to the file instead.
+		if ( ! $wp_filesystem->delete( $old_file, true ) && $wp_filesystem->is_file( $old_file ) ) {
+			$wp_filesystem->put_contents( $old_file, '' );
+		}
 	}
 
 	// Remove any Genericons example.html's from the filesystem
diff --git a/wp-includes/version.php b/wp-includes/version.php
index 937d54af6d..f4b8fd2fb0 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '5.0-alpha-42432';
+$wp_version = '5.0-alpha-42433';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.