Ticket #50571: 50571.2.diff

src/wp-includes/sitemaps/providers/class-wp-sitemaps-posts.php

@@ -174 +174 @@
 
                 $query = new WP_Query( $args );
 
-                return isset( $query->max_num_pages ) ? $query->max_num_pages : 1;
+                $min_num_pages = ( 'page' === $post_type && 'posts' === get_option( 'show_on_front' ) ) ? 1 : 0;
+                return isset( $query->max_num_pages ) ? max( $min_num_pages, $query->max_num_pages ) : 1;
         }
 
         /**

tests/phpunit/tests/sitemaps/sitemaps-posts.php

@@ -4 +4 @@
  * @group sitemaps
  */
 class Test_WP_Sitemaps_Posts extends WP_UnitTestCase {
+        /**
+         * Tests getting sitemap entries for post type page with 'posts' homepage.
+         *
+         * Ensures that an entry is added even if there are no pages.
+         *
+         * @ticket 50571
+         */
+        public function test_get_sitemap_entries_homepage() {
+                update_option( 'show_on_front', 'posts' );
+
+                $posts_provider = new WP_Sitemaps_Posts();
+
+                $post_list = $posts_provider->get_sitemap_entries();
+
+                $expected = array(
+                        array(
+                                'loc' => home_url( '/?sitemap=posts&sitemap-subtype=page&paged=1' ),
+                        ),
+                );
+
+                $this->assertEquals( $expected, $post_list );
+        }
+
         /**
          * Test ability to filter object subtypes.
          */