Add upstream

wp-content/plugins/jetpack/modules/sitemaps/sitemap-buffer-master-fallback.php

@@ -0,0 +1,38 @@
+<?php
+/**
+ * Sitemaps (per the protocol) are essentially lists of XML fragments;
+ * lists which are subject to size constraints. The Jetpack_Sitemap_Buffer_Master
+ * extends the Jetpack_Sitemap_Buffer class to represent the master sitemap
+ * buffer.
+ *
+ * @since 5.3.0
+ * @package Jetpack
+ */
+
+/**
+ * A buffer for constructing master sitemap xml files for users without libxml support.
+ *
+ * @since 5.3.0
+ */
+class Jetpack_Sitemap_Buffer_Master extends Jetpack_Sitemap_Buffer_Fallback {
+
+	protected function get_root_element() {
+
+		if ( ! isset( $this->root ) ) {
+
+			$sitemap_index_xsl_url = $this->finder->construct_sitemap_url( 'sitemap-index.xsl' );
+			$jetpack_version       = JETPACK__VERSION;
+
+			$this->root = array(
+				"<!-- generator='jetpack-{$jetpack_version}' -->" . PHP_EOL
+				. "<?xml-stylesheet type='text/xsl' href='{$sitemap_index_xsl_url}'?>" . PHP_EOL
+				. "<sitemapindex xmlns='http://www.sitemaps.org/schemas/sitemap/0.9'>" . PHP_EOL,
+				'</sitemapindex>',
+			);
+
+			$this->byte_capacity -= strlen( join( '', $this->root ) );
+		}
+
+		return $this->root;
+	}
+}