Ticket #44052: 44052.5.diff

src/wp-login.php

@@ -38 +38 @@
 
         add_action( 'login_head', 'wp_login_viewport_meta' );
 
-        if ( empty( $wp_error ) ) {
+        if ( ! is_wp_error( $wp_error ) ) {
                 $wp_error = new WP_Error();
         }
 

tests/phpunit/tests/http/getHttpHeaders.php

@@ -50 +50 @@
                 wp_get_http_headers( 'does_not_matter', $deprecated = true );
         }
 
+        /**
+         * Test to check if login_header is getting error argument.
+         */
+
+        public function test_wp_get_http_headers_login() {
+                $result = login_header( 'Log In', '', 'Test.' );
+                $this->assertWPError();
+        }
+