Ticket #47642: 47642.2.diff

tests/phpunit/tests/query/orderby.php

@@ +1 @@
+<?php
+
+/**
+ * Tests for query result ordering, specifically indeterminate ordering.
+ *
+ * @group query
+ */
+class Tests_Query_Orderby extends WP_UnitTestCase {
+        function test_order_by_comment_count_does_not_cause_duplication_when_paginating() {
+                global $wpdb;
+
+                $posts = self::factory()->post->create_many( 5 );
+
+                $wpdb->update(
+                        $wpdb->posts,
+                        array(
+                                'comment_count' => 50,
+                        ),
+                        array(
+                                'ID' => $posts[2],
+                        )
+                );
+                $wpdb->update(
+                        $wpdb->posts,
+                        array(
+                                'comment_count' => 100,
+                        ),
+                        array(
+                                'ID' => $posts[4],
+                        )
+                );
+                $args = array(
+                        'posts_per_page' => 1,
+                        'paged'          => 1,
+                        'orderby'        => 'comment_count',
+                        'order'          => 'desc',
+                );
+
+                $query    = new WP_Query( $args );
+                $actual   = array();
+                $expected = array(
+                        $posts[4], // 100 comments
+                        $posts[2], // 50 comments
+                        $posts[3], // 0 comments
+                        $posts[1], // 0 comments
+                        $posts[0], // 0 comments
+                );
+
+                while ( $query->have_posts() ) {
+                        $actual = array_merge( $actual, wp_list_pluck( $query->posts, 'ID' ) );
+                        $args['paged']++;
+                        $query = new WP_Query( $args );
+                }
+
+                $this->assertSame( $expected, $actual );
+        }
+}