Ticket #39692: 39692.2.diff

src/wp-includes/default-filters.php

@@ -264 +264 @@
 add_action( 'template_redirect',   'wp_shortlink_header',             11, 0 );
 add_action( 'wp_print_footer_scripts', '_wp_footer_scripts'                 );
 add_action( 'init',                'check_theme_switched',            99    );
+add_action( 'after_switch_theme',  '_wp_menus_changed'                      );
 add_action( 'after_switch_theme',  '_wp_sidebars_changed'                   );
 add_action( 'wp_print_styles',     'print_emoji_styles'                     );
 

src/wp-includes/nav-menu.php

@@ -1006 +1006 @@
         }
         add_action( 'delete_post', '_wp_delete_customize_changeset_dependent_auto_drafts' );
 }
+
+/**
+ * Handle menu config after theme change.
+ *
+ * @access private
+ * @since 4.9.0
+ */
+function _wp_menus_changed() {
+        $old_nav_menu_locations = get_option( 'theme_switch_menu_locations', array() );
+        $new_nav_menu_locations = get_nav_menu_locations();
+        $registered_nav_menus   = get_registered_nav_menus();
+
+        // If old and new theme have just one location, map it.
+        if ( 1 === count( $old_nav_menu_locations ) && 1 === count( $registered_nav_menus ) ) {
+                $new_nav_menu_locations[ key( $registered_nav_menus ) ] = array_pop( $old_nav_menu_locations );
+        } else {
+                $old_locations = array_keys( $old_nav_menu_locations );
+
+                // Map locations with the same slug.
+                foreach ( $registered_nav_menus as $location => $name ) {
+                        if ( in_array( $location, $old_locations ) ) {
+                                $new_nav_menu_locations[ $location ] = $old_nav_menu_locations[ $location ];
+                                unset( $old_nav_menu_locations[ $location ] );
+                        }
+                }
+
+                if ( ! empty( $old_nav_menu_locations ) ) {
+                        /*
+                         * If old and new theme both have locations that contain phrases
+                         * from within the same group, make an educated guess and map it.
+                         */
+                        $common_slug_groups = array(
+                                array( 'header', 'main', 'navigation', 'primary', 'top' ),
+                                array( 'bottom', 'footer', 'secondary', 'subsidiary' ),
+                                array( 'social' ), // TODO: Find a second slug or remove, since locations with same slug are already mapped.
+                        );
+
+                        // Go through each group...
+                        foreach ( $common_slug_groups as $slug_group ) {
+
+                                // ...and see if any of these slugs...
+                                foreach ( $slug_group as $slug ) {
+
+                                        // ...and any of the new menu locations...
+                                        foreach ( $registered_nav_menus as $new_location => $name ) {
+
+                                                // ...actually match!
+                                                if ( false !== stripos( $new_location, $slug ) || false !== stripos( $slug, $new_location ) ) {
+
+                                                        // Then see if any of the old locations...
+                                                        foreach ( $old_nav_menu_locations as $location => $menu_id ) {
+
+                                                                // ...match a slug in the same group.
+                                                                foreach ( $slug_group as $slug ) {
+                                                                        if ( false !== stripos( $location, $slug ) || false !== stripos( $slug, $location ) ) {
+
+                                                                                // Make sure this location wasn't mapped and removed previously.
+                                                                                if ( ! empty( $old_nav_menu_locations[ $location ] ) ) {
+
+                                                                                        // We have a match that can be mapped!
+                                                                                        $new_nav_menu_locations[ $new_location ] = $old_nav_menu_locations[ $location ];
+
+                                                                                        // Remove the mapped location so it can't be mapped again.
+                                                                                        unset( $old_nav_menu_locations[ $location ] );
+
+                                                                                        // Go back and check the next new menu location.
+                                                                                        continue 3;
+                                                                                }
+                                                                        }
+                                                                }
+                                                        }
+                                                }
+                                        }
+                                }
+                        }
+                }
+        }
+
+        set_theme_mod( 'nav_menu_locations', $new_nav_menu_locations );
+        delete_option( 'theme_switch_menu_locations' );
+}

src/wp-includes/theme.php

@@ -690 +690 @@
         }
 
         $nav_menu_locations = get_theme_mod( 'nav_menu_locations' );
+        add_option( 'theme_switch_menu_locations', $nav_menu_locations );
 
         if ( func_num_args() > 1 ) {
                 $stylesheet = func_get_arg( 1 );
@@ -730 +731 @@
                 if ( 'wp_ajax_customize_save' === current_action() ) {
                         remove_theme_mod( 'sidebars_widgets' );
                 }
-
-                if ( ! empty( $nav_menu_locations ) ) {
-                        $nav_mods = get_theme_mod( 'nav_menu_locations' );
-                        if ( empty( $nav_mods ) ) {
-                                set_theme_mod( 'nav_menu_locations', $nav_menu_locations );
-                        }
-                }
         }
 
         update_option( 'theme_switched', $old_theme->get_stylesheet() );

tests/phpunit/tests/menu/nav-menu.php

@@ +1 @@
+<?php
+
+/**
+ * @group navmenus
+ */
+class Tests_Nav_Menu_Theme_Change extends WP_UnitTestCase {
+
+        function setUp() {
+                register_nav_menus( array(
+                        'primary' => 'Primary',
+                ) );
+
+                parent::setUp();
+        }
+
+        function tearDown() {
+                global $_wp_registered_nav_menus;
+
+                remove_theme_mod( 'nav_menu_locations' );
+                $_wp_registered_nav_menus = array();
+
+                parent::tearDown();
+        }
+
+        /**
+         * Two themes with one location each should just map.
+         */
+        function test_one_location_each() {
+                $old_nav_menu_locations = array( 'unique-slug' => 1 );
+                update_option( 'theme_switch_menu_locations', $old_nav_menu_locations );
+
+                _wp_menus_changed();
+                $this->assertEqualSets( get_theme_mod( 'nav_menu_locations' ), $old_nav_menu_locations );
+        }
+
+        /**
+         * Locations with the same name should map.
+         */
+        function test_locations_with_same_slug() {
+                $old_nav_menu_locations = array( 'primary' => 1, 'secondary' => 2 );
+                update_option( 'theme_switch_menu_locations', $old_nav_menu_locations );
+                register_nav_menu( 'secondary', 'Secondary' );
+
+                _wp_menus_changed();
+                $this->assertEqualSets( get_theme_mod( 'nav_menu_locations' ), $old_nav_menu_locations );
+        }
+
+        /**
+         * If the new theme was previously active, we should fall back to that data.
+         */
+        function test_new_theme_previously_active() {
+                $old_nav_menu_locations = array( 'primary' => 3 );
+                update_option( 'theme_switch_menu_locations', $old_nav_menu_locations );
+                $previous_locations = array( 'primary' => 1, 'secondary' => 2 );
+                set_theme_mod( 'nav_menu_locations', $previous_locations );
+
+                _wp_menus_changed();
+                $this->assertEqualSets( get_theme_mod( 'nav_menu_locations' ), array_merge( $previous_locations, $old_nav_menu_locations ) );
+        }
+
+        /**
+         * Make educated guesses on theme locations.
+         */
+        function test_location_guessing() {
+                $old_nav_menu_locations = array( 'header' => 1, 'footer' => 2 );
+                update_option( 'theme_switch_menu_locations', $old_nav_menu_locations );
+                register_nav_menu( 'secondary', 'Secondary' );
+
+                _wp_menus_changed();
+                $this->assertEqualSets( get_theme_mod( 'nav_menu_locations' ), array( 'primary' => 1, 'secondary' => 2 ) );
+        }
+
+        /**
+         * Make sure two locations that fall in the same group don't get the same menu assigned.
+         */
+        function test_location_guessing_one_menu_per_group() {
+                $old_nav_menu_locations = array( 'top-menu' => 1, 'secondary' => 2 );
+                update_option( 'theme_switch_menu_locations', $old_nav_menu_locations );
+                register_nav_menu( 'main', 'Main' );
+
+                _wp_menus_changed();
+                $this->assertEqualSets( get_theme_mod( 'nav_menu_locations' ), array( 'main' => 1 ) );
+        }
+
+        /**
+         * Make sure two locations that fall in the same group get menus assigned from the same group.
+         */
+        function test_location_guessing_one_menu_per_location() {
+                $old_nav_menu_locations = array( 'navigation-menu' => 1, 'top-menu' => 2 );
+                update_option( 'theme_switch_menu_locations', $old_nav_menu_locations );
+                register_nav_menu( 'main', 'Main' );
+
+                _wp_menus_changed();
+                $this->assertEqualSets( get_theme_mod( 'nav_menu_locations' ), array( 'main' => 1, 'primary' => 2 ) );
+        }
+}