Title: Duplicate checking Last modified: June 19, 2019 --- # Duplicate checking * [David Anderson / Team Updraft](https://wordpress.org/support/users/davidanderson/) * (@davidanderson) * [6 years, 11 months ago](https://wordpress.org/support/topic/duplicate-checking/) * Hi, * Thank you for this plugin. I encountered the following issue: * – If I tick “Login Form” as an “Enabled Form”, then your plugin will check for a captcha response on the login form created by [https://wordpress.org/plugins/wp-user-manager/](https://wordpress.org/plugins/wp-user-manager/)– but does not output any captcha onto that form. This results in inability to login; you always get the ‘Please solve Captcha correctly’ message. * – So, I added an mu-plugin to add the captcha to the form: * ``` add_action('wpum_before_submit_button_login_form', 'my_wpum_before_submit_button_login_form'); function my_wpum_before_submit_button_login_form() { do_action( 'anr_captcha_form_field' ); } ``` * That did add it to the form, and the Google Captcha field to what was then POST- ed to the WP site upon submitting the form. Unfortunately, this still results in ‘Please solve Captcha correctly’ always. So, I investigated why. To investigate why, I added some debug logging inside of `anr_verify_captcha()`. * – This revealed that `anr_verify_captcha()` was getting called twice. The first time, it returns `true`; the second time, false, because what came back in the response body from Google was: * ``` { "success": false, "error-codes": [ "timeout-or-duplicate" ] } ``` * i.e. On the second check of the same data, it got an error for being a duplicate. * I was able to fix this on the site by writing another mu-plugin function to detect duplicates where the first attempt was successful. You might want to adjust that directly in your plugin though, to handle such cases. Here’s the mu-plugin function I used: * ``` add_filter('anr_verify_captcha', 'my_anr_verify_captcha', 10, 3); function my_anr_verify_captcha($verify, $result, $response) { static $seen_response = false; static $seen_verify = null; if (true == $seen_verify && false == $verify && $response == $seen_response && !empty($result['error-codes']) && array('timeout-or-duplicate') == $result['error-codes']) { return true; } else { $seen_verify = $verify; $seen_response = $response; } return $verify; } ``` * Out of interest, here are the two routes that came into `anr_verify_capture()`, causing the duplicate lookup: * 1: `require('wp-blog-header.php'), wp, WP->main, do_action_ref_array('wp'), WP_Hook- >do_action, WP_Hook->apply_filters, WPUM_Form->process, WPUM_Form_Login->submit_handler, wp_authenticate, apply_filters('authenticate'), WP_Hook->apply_filters, anr_captcha_class- >login_verify, anr_captcha_class->verify, anr_verify_captcha` * 2: `require('wp-blog-header.php'), wp, WP->main, do_action_ref_array('wp'), WP_Hook- >do_action, WP_Hook->apply_filters, WPUM_Form->process, WPUM_Form->process, WPUM_Form_Login- >done, wp_signon, wp_authenticate, apply_filters('authenticate'), WP_Hook->apply_filters, anr_captcha_class->login_verify, anr_captcha_class->verify, anr_verify_captcha` Viewing 3 replies - 1 through 3 (of 3 total) * [Shamim Hasan](https://wordpress.org/support/users/shamim51/) * (@shamim51) * [6 years, 11 months ago](https://wordpress.org/support/topic/duplicate-checking/#post-11655255) * Thank you very much for details. I see that plugin is calling `wp_authenticate` function twice (`wp_signon` also call this function) which fire `authenticate` hook twice. * I believe this commit will solve this issue [https://github.com/shamim2883/advanced-nocaptcha-recaptcha/commit/f4356d0831efce65f8081a71e0713d1ceeaf9c5d](https://github.com/shamim2883/advanced-nocaptcha-recaptcha/commit/f4356d0831efce65f8081a71e0713d1ceeaf9c5d) * Let me know. * Thread Starter [David Anderson / Team Updraft](https://wordpress.org/support/users/davidanderson/) * (@davidanderson) * [6 years, 11 months ago](https://wordpress.org/support/topic/duplicate-checking/#post-11655890) * [@shamim51](https://wordpress.org/support/users/shamim51/) Thanks, though, I note that the change just caches the last result and doesn’t key it by the response being checked. Will that work if you have more than one captcha? I notice that your Pro plugin mentions a feature “Allow multiple captcha in same page”. * [Shamim Hasan](https://wordpress.org/support/users/shamim51/) * (@shamim51) * [6 years, 11 months ago](https://wordpress.org/support/topic/duplicate-checking/#post-11656965) * [@davidanderson](https://wordpress.org/support/users/davidanderson/) Thanks again. Free version also support “Allow multiple captcha in same page”. * Result is cached in a static variable which will last one page load. As we cannot submit more than one form at a time it will just restrict multiple call to google api within that form. * When another form will be submitted it will then validate again. Viewing 3 replies - 1 through 3 (of 3 total) The topic ‘Duplicate checking’ is closed to new replies. * ![](https://ps.w.org/advanced-nocaptcha-recaptcha/assets/icon-256x256.png?rev =2961544) * [CAPTCHA 4WP - Antispam CAPTCHA solution for WordPress](https://wordpress.org/plugins/advanced-nocaptcha-recaptcha/) * [Frequently Asked Questions](https://wordpress.org/plugins/advanced-nocaptcha-recaptcha/#faq) * [Support Threads](https://wordpress.org/support/plugin/advanced-nocaptcha-recaptcha/) * [Active Topics](https://wordpress.org/support/plugin/advanced-nocaptcha-recaptcha/active/) * [Unresolved Topics](https://wordpress.org/support/plugin/advanced-nocaptcha-recaptcha/unresolved/) * [Reviews](https://wordpress.org/support/plugin/advanced-nocaptcha-recaptcha/reviews/) * 3 replies * 2 participants * Last reply from: [Shamim Hasan](https://wordpress.org/support/users/shamim51/) * Last activity: [6 years, 11 months ago](https://wordpress.org/support/topic/duplicate-checking/#post-11656965) * Status: not resolved