Merged in feature/from-pantheon (pull request #16)

code from pantheon

* code from pantheon

wp/wp-content/plugins/imagify/inc/3rd-party/hosting/wordpress-com.php

@@ -0,0 +1,30 @@
+<?php
+defined( 'ABSPATH' ) || die( 'Cheatin’ uh?' );
+
+if ( defined( 'WPCOMSH_VERSION' ) ) :
+
+	add_filter( 'imagify_site_root', 'imagify_wpcom_site_root', IMAGIFY_INT_MAX );
+	/**
+	 * Filter the path to the site's root.
+	 *
+	 * @since  1.8.4
+	 * @author Grégory Viguier
+	 *
+	 * @param  string|null $root_path Path to the site's root. Default is null.
+	 * @return string|null
+	 */
+	function imagify_wpcom_site_root( $root_path ) {
+		$upload_basedir = imagify_get_filesystem()->get_upload_basedir( true );
+
+		if ( strpos( $upload_basedir, '/wp-content/' ) === false ) {
+			// Uh oooooh...
+			return $root_path;
+		}
+
+		$upload_basedir = explode( '/wp-content/', $upload_basedir );
+		$upload_basedir = reset( $upload_basedir );
+
+		return $upload_basedir . '/';
+	}
+
+endif;