commit e179a2543f99a90ea55f314e422e9e3db95b9f67
Author: Roman Chernikov <learn@readntry.com>
Date:   Wed Jul 29 23:05:34 2015 -0700

    Add spam control after WordPres upgrade

diff --git a/wp-comments-post.php b/wp-comments-post.php
index 2c421d3..54a97e4 100644
--- a/wp-comments-post.php
+++ b/wp-comments-post.php
@@ -22,6 +22,14 @@ require( dirname(__FILE__) . '/wp-load.php' );
 
 nocache_headers();
 
+$comment_spam_control = ( isset($_POST['spam-control']) ) ? trim($_POST['spam-control']) : null;
+	if ('7' != ($comment_spam_control) ) {
+		$user = wp_get_current_user();
+		if ( ! $user->exists() ) {
+			wp_die( __( "<strong>ERROR</strong>: The comment could not be saved. You entered wrong digit. Go back and try again." ) );
+		}
+	}
+
 $comment = wp_handle_comment_submission( wp_unslash( $_POST ) );
 if ( is_wp_error( $comment ) ) {
 	$data = intval( $comment->get_error_data() );
diff --git a/wp-includes/comment-template.php b/wp-includes/comment-template.php
index c914796..6471dfd 100644
--- a/wp-includes/comment-template.php
+++ b/wp-includes/comment-template.php
@@ -2199,6 +2199,8 @@ function comment_form( $args = array(), $post_id = null ) {
 		            '<input id="email" name="email" ' . ( $html5 ? 'type="email"' : 'type="text"' ) . ' value="' . esc_attr(  $commenter['comment_author_email'] ) . '" size="30" maxlength="100" aria-describedby="email-notes"' . $aria_req . $html_req  . ' /></p>',
 		'url'    => '<p class="comment-form-url"><label for="url">' . __( 'Website' ) . '</label> ' .
 		            '<input id="url" name="url" ' . ( $html5 ? 'type="url"' : 'type="text"' ) . ' value="' . esc_attr( $commenter['comment_author_url'] ) . '" size="30" maxlength="200" /></p>',
+		'spam-control'    => '<p class="comment-form-spam-control"><label for="spam-control">' . __( 'Type one digit: 2 + 3 plus two = ?' ) . '</label>' .
+		             '<input id="spam-control" name="spam-control" type="text" value="" size="30" /></p>',
 	);
 
 	$required_text = sprintf( ' ' . __('Required fields are marked %s'), '<span class="required">*</span>' );