Redirect if trash empty

src/wp-admin/edit.php

@@ -188,6 +188,13 @@
 				++$deleted;
 			}
 			$sendback = add_query_arg( 'deleted', $deleted, $sendback );
+
+			if ( isset( $_REQUEST['post_status'] ) && 'trash' === $_REQUEST['post_status'] ) {
+				$post_counts = (array) wp_count_posts( $post_type, 'readable' );
+				if ( empty( $post_counts['trash'] ) ) {
+					$sendback = remove_query_arg( array( 'post_status', 'paged' ), $sendback );
+				}
+			}
 			break;
 		case 'edit':
 			if ( isset( $_REQUEST['bulk_edit'] ) ) {
@@ -234,6 +241,12 @@
 
 $wp_list_table->prepare_items();
 
+if ( ! $wp_list_table->has_items() && isset( $_REQUEST['post_status'] ) && 'trash' === $_REQUEST['post_status'] ) {
+	$sendback = remove_query_arg( array( 'post_status', 'paged' ), wp_unslash( $_SERVER['REQUEST_URI'] ) );
+	wp_redirect( $sendback );
+	exit;
+}
+
 wp_enqueue_script( 'inline-edit-post' );
 wp_enqueue_script( 'heartbeat' );
 

tests/phpunit/tests/admin/testTrashRedirect.php

@@ -0,0 +1,96 @@
+<?php
+/**
+ * @group admin
+ */
+class Tests_Admin_TrashRedirect extends WP_UnitTestCase {
+	protected $admin_user_id;
+
+	public function set_up() {
+		parent::set_up();
+		$this->admin_user_id = self::factory()->user->create( array( 'role' => 'administrator' ) );
+		wp_set_current_user( $this->admin_user_id );
+
+		// Ensure we are in the admin context.
+		set_current_screen( 'edit-post' );
+
+		// Define ABSPATH if not defined (though it should be in tests).
+		if ( ! defined( 'ABSPATH' ) ) {
+			define( 'ABSPATH', dirname( __DIR__, 4 ) . '/src/' );
+		}
+
+		add_filter( 'wp_redirect', array( $this, 'catch_redirect' ), 1, 1 );
+	}
+
+	public function tear_down() {
+		remove_filter( 'wp_redirect', array( $this, 'catch_redirect' ), 1 );
+		parent::tear_down();
+	}
+
+	public function catch_redirect( $location ) {
+		throw new Tests_Admin_TrashRedirect_Exception( $location );
+	}
+
+	/**
+	 * Test that visiting an empty trash view redirects to all posts view.
+	 */
+	public function test_empty_trash_view_redirects_to_all_posts() {
+		// Mock the request for empty trash.
+		$_GET['post_status']     = 'trash';
+		$_GET['post_type']       = 'post';
+		$_REQUEST['post_status'] = 'trash';
+		$_SERVER['REQUEST_URI']  = admin_url( 'edit.php?post_status=trash' );
+
+		try {
+			ob_start();
+			include ABSPATH . 'wp-admin/edit.php';
+			ob_end_clean();
+		} catch ( Tests_Admin_TrashRedirect_Exception $e ) {
+			ob_end_clean();
+			$this->assertStringNotContainsString( 'post_status=trash', $e->get_location() );
+			$this->assertStringContainsString( 'edit.php', $e->get_location() );
+			return;
+		}
+
+		$this->fail( 'Redirect expected when visiting empty trash view.' );
+	}
+
+	/**
+	 * Test that emptying trash via 'delete_all' redirects to all posts view.
+	 */
+	public function test_empty_trash_action_redirects_to_all_posts() {
+		// Create a post in trash.
+		$post_id = self::factory()->post->create( array( 'post_status' => 'trash' ) );
+
+		$_REQUEST['post_status'] = 'trash';
+		$_REQUEST['post_type']   = 'post';
+		$_REQUEST['action']      = 'delete_all';
+		$_REQUEST['_wpnonce']    = wp_create_nonce( 'bulk-posts' );
+		$_SERVER['REQUEST_URI']  = admin_url( 'edit.php?post_status=trash' );
+		$_SERVER['HTTP_REFERER'] = admin_url( 'edit.php?post_status=trash' );
+
+		try {
+			ob_start();
+			include ABSPATH . 'wp-admin/edit.php';
+			ob_end_clean();
+		} catch ( Tests_Admin_TrashRedirect_Exception $e ) {
+			ob_end_clean();
+			$this->assertStringNotContainsString( 'post_status=trash', $e->get_location() );
+			$this->assertStringContainsString( 'edit.php', $e->get_location() );
+			// Check if post is actually deleted.
+			$this->assertNull( get_post( $post_id ) );
+			return;
+		}
+
+		$this->fail( 'Redirect expected after emptying trash.' );
+	}
+}
+
+class Tests_Admin_TrashRedirect_Exception extends Exception {
+	protected $location;
+	public function __construct( $location ) {
+		$this->location = $location;
+	}
+	public function get_location() {
+		return $this->location;
+	}
+}