Ticket #33800: 33800_with_testcase.diff

src/wp-admin/includes/user.php

@@ -273 +273 @@
 function wp_delete_user( $id, $reassign = null ) {
         global $wpdb;
 
-        $id = (int) $id;
+        if ( ! is_numeric( $id ) && ! $id instanceof WP_User  )
+                return false;
+     
         $user = new WP_User( $id );
 
         if ( !$user->exists() )

tests/phpunit/tests/user.php

@@ -804 +804 @@
                 $user = get_userdata( $user_id );
                 $this->assertEquals( $user->user_email, 'test2@test.com' );
         }
+        /**
+         * @ticket 33800
+         */
+        function test_delete_user_error_check() {
+                // Create a test user.
+                $user_id = $this->factory->user->create( array(
+                        'user_email' => 'ilovewordpress@example.com',
+                ) );
+                // set data for new user with same email id
+                $userdata = array(
+                        'user_login' => 'login_name',
+                        'user_email' => 'ilovewordpress@example.com',
+                'user_pass'  => 'mysecretkey'  // When creating an user, `user_pass` is expected.
+                );
+                // create new user with email already exists.
+                $id = wp_insert_user($userdata);
+                // delete that user but $id is actually WP_Error so wp_delete_user should return false.
+                $is_deleted = wp_delete_user( $id );
+                // check if wp_delete_user returned false
+                $this->assertFalse( $is_deleted );
+        }
 
 }