Posts, Post Types: Add default menu_icon values for built-in post types.

This allows the icons to be retrieved via `get_post_type_object()`.

Props m.usama.masood, michael.ecklund, SergeyBiryukov.
Fixes #38844.

git-svn-id: https://develop.svn.wordpress.org/trunk@47196 602fd350-edb4-49c9-b593-d223f7449a82

Author: SergeyBiryukov

src/wp-includes/post.php

@@ -30,6 +30,7 @@ function create_initial_post_types() {
 			'capability_type'       => 'post',
 			'map_meta_cap'          => true,
 			'menu_position'         => 5,
+			'menu_icon'             => 'dashicons-admin-post',
 			'hierarchical'          => false,
 			'rewrite'               => false,
 			'query_var'             => false,
@@ -54,6 +55,7 @@ function create_initial_post_types() {
 			'capability_type'       => 'page',
 			'map_meta_cap'          => true,
 			'menu_position'         => 20,
+			'menu_icon'             => 'dashicons-admin-page',
 			'hierarchical'          => true,
 			'rewrite'               => false,
 			'query_var'             => false,
@@ -85,6 +87,7 @@ function create_initial_post_types() {
 				'create_posts' => 'upload_files',
 			),
 			'map_meta_cap'          => true,
+			'menu_icon'             => 'dashicons-admin-media',
 			'hierarchical'          => false,
 			'rewrite'               => false,
 			'query_var'             => false,

tests/phpunit/tests/post/types.php

@@ -263,6 +263,15 @@ public function test_get_post_type_object_casting() {
 		_unregister_post_type( 'foo' );
 	}
 
+	/**
+	 * @ticket 38844
+	 */
+	public function test_get_post_type_object_includes_menu_icon_for_builtin_post_types() {
+		$this->assertEquals( 'dashicons-admin-post', get_post_type_object( 'post' )->menu_icon );
+		$this->assertEquals( 'dashicons-admin-page', get_post_type_object( 'page' )->menu_icon );
+		$this->assertEquals( 'dashicons-admin-media', get_post_type_object( 'attachment' )->menu_icon );
+	}
+
 	/**
 	 * @ticket 14761
 	 */