Use the site information on login page

Improves the login page by settings site information on login logo.
Even if it can seem legit, it's not expected to go to wordpress.org
when clicking on the WordPress logo on the login page of YOUR site.

includes/admin.php

@@ -183,3 +183,31 @@ function thistle_hide_default_post_format_option() {
     }
 }
 add_action( 'admin_head-options-writing.php', 'thistle_hide_default_post_format_option' );
+
+if ( ! function_exists( 'thistle_login_headerurl' ) ) {
+    /**
+     * Sets the link URL of the header logo above login form with
+     * the Site Address. By default WordPress uses `https://wordpress.org/`.
+     *
+     * @param string $login_header_url Login header logo URL.
+     * @return string
+     */
+    function thistle_login_headerurl( $url ) {
+        return get_home_url( '/' );
+    }
+}
+add_filter( 'login_headerurl', 'thistle_login_headerurl' );
+
+if ( ! function_exists( 'thistle_login_headertitle' ) ) {
+    /**
+     * Sets the title attribute of the header logo above login form with
+     * the Site Title. By default WordPress uses "Powered by WordPress".
+     *
+     * @param string $login_header_title Login header logo title attribute.
+     * @return string
+     */
+    function thistle_login_headertitle( $title ) {
+        return get_bloginfo( 'name', 'display' );
+    }
+}
+add_filter( 'login_headertitle', 'thistle_login_headertitle' );