Fixing line 149 in wp-admin/includes/file.php does indeed do the trick. One thing to keep in mind: if you have a site on 4.2 and want to get it to 4.2.1 for the security patches, you likely need to patch that line. Then if you want to update plugins, you’ll need to patch that line again since the 4.2.1 update will overwrite file.php.
Sure hope this is fixed in 4.2.2. It’s keeping auto-updates from applying in addition to interfering with updates of plugins, themes and core wordpress itself.
