Ticket #43517: 43517.2.patch

src/wp-includes/capabilities.php

@@ -534 +534 @@
                                 break;
                         }
 
-                        if ( 'delete_term' === $cap && ( get_option( 'default_' . $term->taxonomy ) == $term->term_id ) ) {
+                        if ( 'delete_term' === $cap && ( get_option( 'default_' . $term->taxonomy ) == $term->term_id || get_option( 'default_taxonomy_' . $term->taxonomy ) == $term->term_id ) ) {
                                 $caps[] = 'do_not_allow';
                                 break;
                         }

src/wp-includes/class-wp-taxonomy.php

@@ -209 +209 @@
          */
         public $rest_controller_class;
 
+        /**
+         * The default term name. If you pass an array you have to set
+         * 'name' and optionally slug' and 'description'.
+         *
+         * @since 5.5.0
+         * @var array|string
+         */
+        public $default_term;
+
         /**
          * Whether it is a built-in taxonomy.
          *
@@ -278 +287 @@
                         'show_in_rest'          => false,
                         'rest_base'             => false,
                         'rest_controller_class' => false,
+                        'default_term'          => null,
                         '_builtin'              => false,
                 );
 
@@ -376 +386 @@
                         }
                 }
 
+                // Default taxonomy term.
+                if ( ! empty( $args['default_term'] ) ) {
+                        if ( ! is_array( $args['default_term'] ) ) {
+                                $args['default_term'] = array( 'name' => $args['default_term'] );
+                        }
+                        $args['default_term'] = wp_parse_args( $args['default_term'], array( 'name' => '', 'slug' => '', 'description' => '' ) );
+                }
+
                 foreach ( $args as $property_name => $property_value ) {
                         $this->$property_name = $property_value;
                 }

src/wp-includes/post.php

@@ -4005 +4005 @@
                 wp_set_post_tags( $post_ID, $postarr['tags_input'] );
         }
 
+        // Add default term for all associated custom taxonomies.
+        if ( 'auto-draft' !== $post_status ) {
+                foreach ( get_object_taxonomies( $post_type, 'object' ) as $taxonomy => $tax_object ) {
+                        if ( ! empty( $tax_object->default_term ) && ( empty( $postarr['tax_input'] ) || ! isset( $postarr['tax_input'][ $taxonomy ] ) ) ) {
+                                $postarr['tax_input'][ $taxonomy ] = array();
+                        }
+                }
+        }
+
         // New-style support for all custom taxonomies.
         if ( ! empty( $postarr['tax_input'] ) ) {
                 foreach ( $postarr['tax_input'] as $taxonomy => $tags ) {

src/wp-includes/taxonomy.php

@@ -335 +335 @@
  *              arguments to register the Taxonomy in REST API.
  * @since 5.1.0 Introduced `meta_box_sanitize_cb` argument.
  * @since 5.4.0 Added the registered taxonomy object as a return value.
+ * @since 5.5.0 Introduced `default_term` argument.
  *
  * @global array $wp_taxonomies Registered taxonomies.
  *
@@ -406 +407 @@
  *                                                to post types, which confirms that the objects are published before
  *                                                counting them. Default _update_generic_term_count() for taxonomies
  *                                                attached to other object types, such as users.
+ *     @type string|array  $default_term {
+ *         Default term to be used for the taxonomy.
+ *
+ *         @type string $name         Name of default term.
+ *         @type string $slug         Slug for default term. Default empty.
+ *         @type string $description  Description for default term. Default empty.
+ *     }
  *     @type bool          $_builtin              This taxonomy is a "built-in" taxonomy. INTERNAL USE ONLY!
  *                                                Default false.
  * }
@@ -432 +440 @@
 
         $taxonomy_object->add_hooks();
 
+        // Add default term.
+        if ( ! empty( $taxonomy_object->default_term ) ) {
+                if ( $term = term_exists( $taxonomy_object->default_term['name'], $taxonomy ) ) {
+                        update_option('default_taxonomy_' . $taxonomy_object->name, $term['term_id'] );
+                } else {
+                        $term = wp_insert_term(
+                                $taxonomy_object->default_term['name'],
+                                $taxonomy,
+                                array(
+                                        'slug'        => sanitize_title( $taxonomy_object->default_term['slug'] ),
+                                        'description' => $taxonomy_object->default_term['description']
+                                )
+                        );
+
+                        // Update term id in options.
+                        if ( ! is_wp_error( $term ) ) {
+                                update_option('default_taxonomy_' . $taxonomy_object->name, $term['term_id'] );
+                        }
+                }
+        }
+
         /**
          * Fires after a taxonomy is registered.
          *
@@ -2452 +2481 @@
                 $terms = array( $terms );
         }
 
+        // Add default term.
+        $taxonomy_obj = get_taxonomy( $taxonomy );
+
+        // Default term for this taxonomy.
+        if ( empty( $terms ) && ! empty ( $taxonomy_obj->default_term ) && ! empty( $default_term_id = get_option( 'default_taxonomy_' . $taxonomy ) ) ) {
+                $terms[] = (int) $default_term_id;
+        }
+
         if ( ! $append ) {
                 $old_tt_ids = wp_get_object_terms(
                         $object_id,

tests/phpunit/tests/taxonomy.php

@@ -965 +965 @@
 
                 $this->assertEquals( $problematic_term, $term_name );
         }
+
+        /**
+         * Test default term for custom taxonomy.
+         *
+         * @ticket 43517
+         */
+        function test_default_term_for_custom_taxonomy() {
+
+                wp_set_current_user( self::factory()->user->create( array( 'role' => 'editor' ) ) );
+
+                $tax = 'custom-tax';
+
+                // Create custom taxonomy to test with.
+                register_taxonomy(
+                        $tax,
+                        'post',
+                        array(
+                                'hierarchical' => true,
+                                'public'       => true,
+                                'default_term' => array(
+                                        'name' => 'Default category',
+                                        'slug' => 'default-category',
+                                )
+                        )
+                );
+
+                // Add post.
+                $post_id = wp_insert_post(
+                        array(
+                                'post_title' => 'Foo',
+                                'post_type' => 'post',
+                        )
+                );
+
+                $term = wp_get_post_terms( $post_id, $tax );
+                $this->assertSame( get_option( 'default_taxonomy_' . $tax ), $term[0]->term_id );
+
+                // Add custom post type.
+                register_post_type(
+                        'post-custom-tax',
+                        array(
+                                'taxonomies' => array( $tax )
+                        )
+                );
+                $post_id = wp_insert_post(
+                        array(
+                                'post_title' => 'Foo',
+                                'post_type'  => 'post-custom-tax',
+                        )
+                );
+                $term = wp_get_post_terms( $post_id, $tax );
+                $this->assertSame( get_option( 'default_taxonomy_' . $tax ), $term[0]->term_id );
+        }
 }