Plugin - akismet update from 4.1.3 to 4.2.1

Signed-off-by: Yury German <blueknight@gentoo.org>

1 files changed, 371 insertions, 106 deletions

diff --git a/plugins/akismet/class.akismet.php b/plugins/akismet/class.akismet.php
index 01753014..1681d0e1 100644
--- a/plugins/akismet/class.akismet.php
+++ b/plugins/akismet/class.akismet.php
@@ -5,12 +5,19 @@ class Akismet {
 	const API_PORT = 80;
 	const MAX_DELAY_BEFORE_MODERATION_EMAIL = 86400; // One day in seconds
 
+	public static $limit_notices = array(
+		10501 => 'FIRST_MONTH_OVER_LIMIT',
+		10502 => 'SECOND_MONTH_OVER_LIMIT',
+		10504 => 'THIRD_MONTH_APPROACHING_LIMIT',
+		10508 => 'THIRD_MONTH_OVER_LIMIT',
+		10516 => 'FOUR_PLUS_MONTHS_OVER_LIMIT',
+	);
+
 	private static $last_comment = '';
 	private static $initiated = false;
 	private static $prevent_moderation_email_for_these_comments = array();
 	private static $last_comment_result = null;
 	private static $comment_as_submitted_allowed_keys = array( 'blog' => '', 'blog_charset' => '', 'blog_lang' => '', 'blog_ua' => '', 'comment_agent' => '', 'comment_author' => '', 'comment_author_IP' => '', 'comment_author_email' => '', 'comment_author_url' => '', 'comment_content' => '', 'comment_date_gmt' => '', 'comment_tags' => '', 'comment_type' => '', 'guid' => '', 'is_test' => '', 'permalink' => '', 'reporter' => '', 'site_domain' => '', 'submit_referer' => '', 'submit_uri' => '', 'user_ID' => '', 'user_agent' => '', 'user_id' => '', 'user_ip' => '' );
-	private static $is_rest_api_call = false;
 	
 	public static function init() {
 		if ( ! self::$initiated ) {
@@ -34,11 +41,7 @@ class Akismet {
 		add_action( 'akismet_schedule_cron_recheck', array( 'Akismet', 'cron_recheck' ) );
 
 		add_action( 'comment_form',  array( 'Akismet',  'add_comment_nonce' ), 1 );
-
-		add_action( 'admin_head-edit-comments.php', array( 'Akismet', 'load_form_js' ) );
-		add_action( 'comment_form', array( 'Akismet', 'load_form_js' ) );
-		add_action( 'comment_form', array( 'Akismet', 'inject_ak_js' ) );
-		add_filter( 'script_loader_tag', array( 'Akismet', 'set_form_js_async' ), 10, 3 );
+		add_action( 'comment_form', array( 'Akismet', 'output_custom_form_fields' ) );
 
 		add_filter( 'comment_moderation_recipients', array( 'Akismet', 'disable_moderation_emails_if_unreachable' ), 1000, 2 );
 		add_filter( 'pre_comment_approved', array( 'Akismet', 'last_comment_status' ), 10, 2 );
@@ -47,9 +50,20 @@ class Akismet {
 
 		// Run this early in the pingback call, before doing a remote fetch of the source uri
 		add_action( 'xmlrpc_call', array( 'Akismet', 'pre_check_pingback' ) );
-		
+
 		// Jetpack compatibility
 		add_filter( 'jetpack_options_whitelist', array( 'Akismet', 'add_to_jetpack_options_whitelist' ) );
+		add_filter( 'jetpack_contact_form_html', array( 'Akismet', 'inject_custom_form_fields' ) );
+		add_filter( 'jetpack_contact_form_akismet_values', array( 'Akismet', 'prepare_custom_form_values' ) );
+
+		// Gravity Forms
+		add_filter( 'gform_get_form_filter', array( 'Akismet', 'inject_custom_form_fields' ) );
+		add_filter( 'gform_akismet_fields', array( 'Akismet', 'prepare_custom_form_values' ) );
+
+		// Contact Form 7
+		add_filter( 'wpcf7_form_elements', array( 'Akismet', 'append_custom_form_fields' ) );
+		add_filter( 'wpcf7_akismet_parameters', array( 'Akismet', 'prepare_custom_form_values' ) );
+
 		add_action( 'update_option_wordpress_api_key', array( 'Akismet', 'updated_option' ), 10, 2 );
 		add_action( 'add_option_wordpress_api_key', array( 'Akismet', 'added_option' ), 10, 2 );
 
@@ -131,12 +145,23 @@ class Akismet {
 	}
 	
 	public static function rest_auto_check_comment( $commentdata ) {
-		self::$is_rest_api_call = true;
-		
-		return self::auto_check_comment( $commentdata );
+		return self::auto_check_comment( $commentdata, 'rest_api' );
 	}
 
-	public static function auto_check_comment( $commentdata ) {
+	/**
+	 * Check a comment for spam.
+	 *
+	 * @param array $commentdata
+	 * @param string $context What kind of request triggered this comment check? Possible values are 'default', 'rest_api', and 'xml-rpc'.
+	 * @return array|WP_Error Either the $commentdata array with additional entries related to its spam status
+	 *                        or a WP_Error, if it's a REST API request and the comment should be discarded.
+	 */
+	public static function auto_check_comment( $commentdata, $context = 'default' ) {
+		// If no key is configured, then there's no point in doing any of this.
+		if ( ! self::get_api_key() ) {
+			return $commentdata;
+		}
+
 		self::$last_comment_result = null;
 
 		$comment = $commentdata;
@@ -202,7 +227,15 @@ class Akismet {
 		do_action( 'akismet_comment_check_response', $response );
 
 		$commentdata['comment_as_submitted'] = array_intersect_key( $comment, self::$comment_as_submitted_allowed_keys );
-		$commentdata['akismet_result']       = $response[1];
+
+		// Also include any form fields we inject into the comment form, like ak_js
+		foreach ( $_POST as $key => $value ) {
+			if ( is_string( $value ) && strpos( $key, 'ak_' ) === 0 ) {
+				$commentdata['comment_as_submitted'][ 'POST_' . $key ] = $value;
+			}
+		}
+
+		$commentdata['akismet_result'] = $response[1];
 
 		if ( isset( $response[0]['x-akismet-pro-tip'] ) )
 	        $commentdata['akismet_pro_tip'] = $response[0]['x-akismet-pro-tip'];
@@ -227,17 +260,19 @@ class Akismet {
 					update_option( 'akismet_spam_count', get_option( 'akismet_spam_count' ) + $incr );
 				}
 
-				if ( self::$is_rest_api_call ) {
+				if ( 'rest_api' === $context ) {
 					return new WP_Error( 'akismet_rest_comment_discarded', __( 'Comment discarded.', 'akismet' ) );
-				}
-				else {
+				} else if ( 'xml-rpc' === $context ) {
+					// If this is a pingback that we're pre-checking, the discard behavior is the same as the normal spam response behavior.
+					return $commentdata;
+				} else {
 					// Redirect back to the previous page, or failing that, the post permalink, or failing that, the homepage of the blog.
 					$redirect_to = isset( $_SERVER['HTTP_REFERER'] ) ? $_SERVER['HTTP_REFERER'] : ( $post ? get_permalink( $post ) : home_url() );
 					wp_safe_redirect( esc_url_raw( $redirect_to ) );
 					die();
 				}
 			}
-			else if ( self::$is_rest_api_call ) {
+			else if ( 'rest_api' === $context ) {
 				// The way the REST API structures its calls, we can set the comment_approved value right away.
 				$commentdata['comment_approved'] = 'spam';
 			}
@@ -296,48 +331,56 @@ class Akismet {
 		// as was checked by auto_check_comment
 		if ( is_object( $comment ) && !empty( self::$last_comment ) && is_array( self::$last_comment ) ) {
 			if ( self::matches_last_comment( $comment ) ) {
-					
-					load_plugin_textdomain( 'akismet' );
-					
-					// normal result: true or false
-					if ( self::$last_comment['akismet_result'] == 'true' ) {
-						update_comment_meta( $comment->comment_ID, 'akismet_result', 'true' );
-						self::update_comment_history( $comment->comment_ID, '', 'check-spam' );
-						if ( $comment->comment_approved != 'spam' )
-							self::update_comment_history(
-								$comment->comment_ID,
-								'',
-								'status-changed-'.$comment->comment_approved
-							);
-					}
-					elseif ( self::$last_comment['akismet_result'] == 'false' ) {
-						update_comment_meta( $comment->comment_ID, 'akismet_result', 'false' );
-						self::update_comment_history( $comment->comment_ID, '', 'check-ham' );
-						// Status could be spam or trash, depending on the WP version and whether this change applies:
-						// https://core.trac.wordpress.org/changeset/34726
-						if ( $comment->comment_approved == 'spam' || $comment->comment_approved == 'trash' ) {
-							if ( wp_blacklist_check($comment->comment_author, $comment->comment_author_email, $comment->comment_author_url, $comment->comment_content, $comment->comment_author_IP, $comment->comment_agent) )
-								self::update_comment_history( $comment->comment_ID, '', 'wp-blacklisted' );
-							else
-								self::update_comment_history( $comment->comment_ID, '', 'status-changed-'.$comment->comment_approved );
-						}
-					} // abnormal result: error
-					else {
-						update_comment_meta( $comment->comment_ID, 'akismet_error', time() );
+				load_plugin_textdomain( 'akismet' );
+
+				// normal result: true or false
+				if ( self::$last_comment['akismet_result'] == 'true' ) {
+					update_comment_meta( $comment->comment_ID, 'akismet_result', 'true' );
+					self::update_comment_history( $comment->comment_ID, '', 'check-spam' );
+					if ( $comment->comment_approved != 'spam' ) {
 						self::update_comment_history(
 							$comment->comment_ID,
 							'',
-							'check-error',
-							array( 'response' => substr( self::$last_comment['akismet_result'], 0, 50 ) )
+							'status-changed-' . $comment->comment_approved
 						);
 					}
+				} elseif ( self::$last_comment['akismet_result'] == 'false' ) {
+					update_comment_meta( $comment->comment_ID, 'akismet_result', 'false' );
+					self::update_comment_history( $comment->comment_ID, '', 'check-ham' );
+					// Status could be spam or trash, depending on the WP version and whether this change applies:
+					// https://core.trac.wordpress.org/changeset/34726
+					if ( $comment->comment_approved == 'spam' || $comment->comment_approved == 'trash' ) {
+						if ( function_exists( 'wp_check_comment_disallowed_list' ) ) {
+							if ( wp_check_comment_disallowed_list( $comment->comment_author, $comment->comment_author_email, $comment->comment_author_url, $comment->comment_content, $comment->comment_author_IP, $comment->comment_agent ) ) {
+								self::update_comment_history( $comment->comment_ID, '', 'wp-disallowed' );
+							} else {
+								self::update_comment_history( $comment->comment_ID, '', 'status-changed-' . $comment->comment_approved );
+							}
+						} else if ( function_exists( 'wp_blacklist_check' ) && wp_blacklist_check( $comment->comment_author, $comment->comment_author_email, $comment->comment_author_url, $comment->comment_content, $comment->comment_author_IP, $comment->comment_agent ) ) {
+							self::update_comment_history( $comment->comment_ID, '', 'wp-blacklisted' );
+						} else {
+							self::update_comment_history( $comment->comment_ID, '', 'status-changed-' . $comment->comment_approved );
+						}
+					}
+				} else {
+					 // abnormal result: error
+					update_comment_meta( $comment->comment_ID, 'akismet_error', time() );
+					self::update_comment_history(
+						$comment->comment_ID,
+						'',
+						'check-error',
+						array( 'response' => substr( self::$last_comment['akismet_result'], 0, 50 ) )
+					);
+				}
 
-					// record the complete original data as submitted for checking
-					if ( isset( self::$last_comment['comment_as_submitted'] ) )
-						update_comment_meta( $comment->comment_ID, 'akismet_as_submitted', self::$last_comment['comment_as_submitted'] );
+				// record the complete original data as submitted for checking
+				if ( isset( self::$last_comment['comment_as_submitted'] ) ) {
+					update_comment_meta( $comment->comment_ID, 'akismet_as_submitted', self::$last_comment['comment_as_submitted'] );
+				}
 
-					if ( isset( self::$last_comment['akismet_pro_tip'] ) )
-						update_comment_meta( $comment->comment_ID, 'akismet_pro_tip', self::$last_comment['akismet_pro_tip'] );
+				if ( isset( self::$last_comment['akismet_pro_tip'] ) ) {
+					update_comment_meta( $comment->comment_ID, 'akismet_pro_tip', self::$last_comment['akismet_pro_tip'] );
+				}
 			}
 		}
 	}
@@ -380,6 +423,10 @@ class Akismet {
 
 			clean_comment_cache( $comment_ids );
 			do_action( 'akismet_delete_comment_batch', count( $comment_ids ) );
+
+			foreach ( $comment_ids as $comment_id ) {
+				do_action( 'deleted_comment', $comment_id );
+			}
 		}
 
 		if ( apply_filters( 'akismet_optimize_table', ( mt_rand(1, 5000) == 11), $wpdb->comments ) ) // lucky number
@@ -469,6 +516,44 @@ class Akismet {
 	// get the full comment history for a given comment, as an array in reverse chronological order
 	public static function get_comment_history( $comment_id ) {
 		$history = get_comment_meta( $comment_id, 'akismet_history', false );
+		if ( empty( $history ) || empty( $history[ 0 ] ) ) {
+			return false;
+		}
+		
+		/*
+		// To see all variants when testing.
+		$history[] = array( 'time' => 445856401, 'message' => 'Old versions of Akismet stored the message as a literal string in the commentmeta.', 'event' => null );
+		$history[] = array( 'time' => 445856402, 'event' => 'recheck-spam' );
+		$history[] = array( 'time' => 445856403, 'event' => 'check-spam' );
+		$history[] = array( 'time' => 445856404, 'event' => 'recheck-ham' );
+		$history[] = array( 'time' => 445856405, 'event' => 'check-ham' );
+		$history[] = array( 'time' => 445856406, 'event' => 'wp-blacklisted' );
+		$history[] = array( 'time' => 445856406, 'event' => 'wp-disallowed' );
+		$history[] = array( 'time' => 445856407, 'event' => 'report-spam' );
+		$history[] = array( 'time' => 445856408, 'event' => 'report-spam', 'user' => 'sam' );
+		$history[] = array( 'message' => 'sam reported this comment as spam (hardcoded message).', 'time' => 445856400, 'event' => 'report-spam', 'user' => 'sam' );
+		$history[] = array( 'time' => 445856409, 'event' => 'report-ham', 'user' => 'sam' );
+		$history[] = array( 'message' => 'sam reported this comment as ham (hardcoded message).', 'time' => 445856400, 'event' => 'report-ham', 'user' => 'sam' ); //
+		$history[] = array( 'time' => 445856410, 'event' => 'cron-retry-spam' );
+		$history[] = array( 'time' => 445856411, 'event' => 'cron-retry-ham' );
+		$history[] = array( 'time' => 445856412, 'event' => 'check-error' ); //
+		$history[] = array( 'time' => 445856413, 'event' => 'check-error', 'meta' => array( 'response' => 'The server was taking a nap.' ) );
+		$history[] = array( 'time' => 445856414, 'event' => 'recheck-error' ); // Should not generate a message.
+		$history[] = array( 'time' => 445856415, 'event' => 'recheck-error', 'meta' => array( 'response' => 'The server was taking a nap.' ) );
+		$history[] = array( 'time' => 445856416, 'event' => 'status-changedtrash' );
+		$history[] = array( 'time' => 445856417, 'event' => 'status-changedspam' );
+		$history[] = array( 'time' => 445856418, 'event' => 'status-changedhold' );
+		$history[] = array( 'time' => 445856419, 'event' => 'status-changedapprove' );
+		$history[] = array( 'time' => 445856420, 'event' => 'status-changed-trash' );
+		$history[] = array( 'time' => 445856421, 'event' => 'status-changed-spam' );
+		$history[] = array( 'time' => 445856422, 'event' => 'status-changed-hold' );
+		$history[] = array( 'time' => 445856423, 'event' => 'status-changed-approve' );
+		$history[] = array( 'time' => 445856424, 'event' => 'status-trash', 'user' => 'sam' );
+		$history[] = array( 'time' => 445856425, 'event' => 'status-spam', 'user' => 'sam' );
+		$history[] = array( 'time' => 445856426, 'event' => 'status-hold', 'user' => 'sam' );
+		$history[] = array( 'time' => 445856427, 'event' => 'status-approve', 'user' => 'sam' );
+		*/
+		
 		usort( $history, array( 'Akismet', '_cmp_time' ) );
 		return $history;
 	}
@@ -506,6 +591,10 @@ class Akismet {
 	public static function check_db_comment( $id, $recheck_reason = 'recheck_queue' ) {
 		global $wpdb;
 
+		if ( ! self::get_api_key() ) {
+			return new WP_Error( 'akismet-not-configured', __( 'Akismet is not configured. Please enter an API key.', 'akismet' ) );
+		}
+
 		$c = $wpdb->get_row( $wpdb->prepare( "SELECT * FROM {$wpdb->comments} WHERE comment_ID = %d", $id ), ARRAY_A );
 		
 		if ( ! $c ) {
@@ -653,6 +742,13 @@ class Akismet {
 		if ( 'spam' != $comment->comment_approved )
 			return;
 
+		self::update_comment_history( $comment_id, '', 'report-spam' );
+
+		// If the user hasn't configured Akismet, there's nothing else to do at this point.
+		if ( ! self::get_api_key() ) {
+			return;
+		}
+
 		// use the original version stored in comment_meta if available
 		$as_submitted = self::sanitize_comment_as_submitted( get_comment_meta( $comment_id, 'akismet_as_submitted', true ) );
 
@@ -685,9 +781,10 @@ class Akismet {
 		}
 
 		$response = Akismet::http_post( Akismet::build_query( $comment ), 'submit-spam' );
+
+		update_comment_meta( $comment_id, 'akismet_user_result', 'true' );
+
 		if ( $comment->reporter ) {
-			self::update_comment_history( $comment_id, '', 'report-spam' );
-			update_comment_meta( $comment_id, 'akismet_user_result', 'true' );
 			update_comment_meta( $comment_id, 'akismet_user', $comment->reporter );
 		}
 
@@ -703,6 +800,13 @@ class Akismet {
 		if ( !$comment ) // it was deleted
 			return;
 
+		self::update_comment_history( $comment_id, '', 'report-ham' );
+
+		// If the user hasn't configured Akismet, there's nothing else to do at this point.
+		if ( ! self::get_api_key() ) {
+			return;
+		}
+
 		// use the original version stored in comment_meta if available
 		$as_submitted = self::sanitize_comment_as_submitted( get_comment_meta( $comment_id, 'akismet_as_submitted', true ) );
 
@@ -735,9 +839,10 @@ class Akismet {
 		}
 
 		$response = self::http_post( Akismet::build_query( $comment ), 'submit-ham' );
+
+		update_comment_meta( $comment_id, 'akismet_user_result', 'false' );
+
 		if ( $comment->reporter ) {
-			self::update_comment_history( $comment_id, '', 'report-ham' );
-			update_comment_meta( $comment_id, 'akismet_user_result', 'false' );
 			update_comment_meta( $comment_id, 'akismet_user', $comment->reporter );
 		}
 
@@ -860,6 +965,11 @@ class Akismet {
 		 * has not been set and that Akismet should just choose the default behavior for that
 		 * situation.
 		 */
+		
+		if ( ! self::get_api_key() ) {
+			return;
+		}
+		
 		$akismet_comment_nonce_option = apply_filters( 'akismet_comment_nonce', get_option( 'akismet_comment_nonce' ) );
 
 		if ( $akismet_comment_nonce_option == 'true' || $akismet_comment_nonce_option == '' ) {
@@ -879,7 +989,7 @@ class Akismet {
 		if ( is_user_logged_in() )
 			return false;
 	
-		return ( get_option( 'akismet_strictness' ) === '1'  );
+		return ( get_option( 'akismet_strictness' ) === '1' );
 	}
 
 	public static function get_ip_address() {
@@ -1029,10 +1139,12 @@ class Akismet {
 		if ( ! empty( self::$prevent_moderation_email_for_these_comments ) && ! empty( $emails ) ) {
 			$comment = get_comment( $comment_id );
 
-			foreach ( self::$prevent_moderation_email_for_these_comments as $possible_match ) {
-				if ( self::comments_match( $possible_match, $comment ) ) {
-					update_comment_meta( $comment_id, 'akismet_delayed_moderation_email', true );
-					return array();
+			if ( $comment ) {
+				foreach ( self::$prevent_moderation_email_for_these_comments as $possible_match ) {
+					if ( self::comments_match( $possible_match, $comment ) ) {
+						update_comment_meta( $comment_id, 'akismet_delayed_moderation_email', true );
+						return array();
+					}
 				}
 			}
 		}
@@ -1163,51 +1275,106 @@ class Akismet {
 
 	// given a response from an API call like check_key_status(), update the alert code options if an alert is present.
 	public static function update_alert( $response ) {
-		$code = $msg = null;
-		if ( isset( $response[0]['x-akismet-alert-code'] ) ) {
-			$code = $response[0]['x-akismet-alert-code'];
-			$msg  = $response[0]['x-akismet-alert-msg'];
-		}
+		$alert_option_prefix = 'akismet_alert_';
+		$alert_header_prefix = 'x-akismet-alert-';
+		$alert_header_names  = array(
+			'code',
+			'msg',
+			'api-calls',
+			'usage-limit',
+			'upgrade-plan',
+			'upgrade-url',
+			'upgrade-type',
+		);
 
-		// only call update_option() if the value has changed
-		if ( $code != get_option( 'akismet_alert_code' ) ) {
-			if ( ! $code ) {
-				delete_option( 'akismet_alert_code' );
-				delete_option( 'akismet_alert_msg' );
+		foreach ( $alert_header_names as $alert_header_name ) {
+			$value = null;
+			if ( isset( $response[0][ $alert_header_prefix . $alert_header_name ] ) ) {
+				$value = $response[0][ $alert_header_prefix . $alert_header_name ];
 			}
-			else {
-				update_option( 'akismet_alert_code', $code );
-				update_option( 'akismet_alert_msg', $msg );
+
+			$option_name = $alert_option_prefix . str_replace( '-', '_', $alert_header_name );
+			if ( $value != get_option( $option_name ) ) {
+				if ( ! $value ) {
+					delete_option( $option_name );
+				} else {
+					update_option( $option_name, $value );
+				}
 			}
 		}
 	}
 
 	public static function load_form_js() {
-		if ( function_exists( 'is_amp_endpoint' ) && is_amp_endpoint() ) {
-			return;
+		/* deprecated */
+	}
+
+	public static function set_form_js_async( $tag, $handle, $src ) {
+		/* deprecated */
+		return $tag;
+	}
+
+	public static function get_akismet_form_fields() {
+		$fields = '';
+
+		$prefix = 'ak_';
+
+		// Contact Form 7 uses _wpcf7 as a prefix to know which fields to exclude from comment_content.
+		if ( 'wpcf7_form_elements' === current_filter() ) {
+			$prefix = '_wpcf7_ak_';
+		}
+
+		$fields .= '<p style="display: none !important;">';
+		$fields .= '<label>&#916;<textarea name="' . $prefix . 'hp_textarea" cols="45" rows="8" maxlength="100"></textarea></label>';
+
+		if ( ! function_exists( 'amp_is_request' ) || ! amp_is_request() ) {
+			$fields .= '<input type="hidden" id="ak_js" name="' . $prefix . 'js" value="' . mt_rand( 0, 250 ) . '"/>';
+			$fields .= '<script>document.getElementById( "ak_js" ).setAttribute( "value", ( new Date() ).getTime() );</script>';
 		}
 
-		wp_register_script( 'akismet-form', plugin_dir_url( __FILE__ ) . '_inc/form.js', array(), AKISMET_VERSION, true );
-		wp_enqueue_script( 'akismet-form' );
+		$fields .= '</p>';
+
+		return $fields;
 	}
-	
+
+	public static function output_custom_form_fields( $post_id ) {
+		// phpcs:ignore WordPress.Security.EscapeOutput
+		echo self::get_akismet_form_fields();
+	}
+
+	public static function inject_custom_form_fields( $html ) {
+		$html = str_replace( '</form>', self::get_akismet_form_fields() . '</form>', $html );
+
+		return $html;
+	}
+
+	public static function append_custom_form_fields( $html ) {
+		$html .= self::get_akismet_form_fields();
+
+		return $html;
+	}
+
 	/**
-	 * Mark form.js as async. Because nothing depends on it, it can run at any time
-	 * after it's loaded, and the browser won't have to wait for it to load to continue
-	 * parsing the rest of the page.
+	 * Ensure that any Akismet-added form fields are included in the comment-check call.
+	 *
+	 * @param array $form
+	 * @return array $form
 	 */
-	public static function set_form_js_async( $tag, $handle, $src ) {
-		if ( 'akismet-form' !== $handle ) {
-			return $tag;
+	public static function prepare_custom_form_values( $form ) {
+		$prefix = 'ak_';
+
+		// Contact Form 7 uses _wpcf7 as a prefix to know which fields to exclude from comment_content.
+		if ( 'wpcf7_akismet_parameters' === current_filter() ) {
+			$prefix = '_wpcf7_ak_';
 		}
-		
-		return preg_replace( '/^<script /i', '<script async="async" ', $tag );
-	}
-	
-	public static function inject_ak_js( $fields ) {
-		echo '<p style="display: none;">';
-		echo '<input type="hidden" id="ak_js" name="ak_js" value="' . mt_rand( 0, 250 ) . '"/>';
-		echo '</p>';
+
+		// phpcs:ignore WordPress.Security.NonceVerification.Missing
+		foreach ( $_POST as $key => $val ) {
+			if ( 0 === strpos( $key, $prefix ) ) {
+				$form[ 'POST_ak_' . substr( $key, strlen( $prefix ) ) ] = $val;
+			}
+		}
+
+		return $form;
 	}
 
 	private static function bail_on_activation( $message, $deactivate = true ) {
@@ -1277,7 +1444,7 @@ p {
 			$message = '<strong>'.sprintf(esc_html__( 'Akismet %s requires WordPress %s or higher.' , 'akismet'), AKISMET_VERSION, AKISMET__MINIMUM_WP_VERSION ).'</strong> '.sprintf(__('Please <a href="%1$s">upgrade WordPress</a> to a current version, or <a href="%2$s">downgrade to version 2.4 of the Akismet plugin</a>.', 'akismet'), 'https://codex.wordpress.org/Upgrading_WordPress', 'https://wordpress.org/extend/plugins/akismet/download/');
 
 			Akismet::bail_on_activation( $message );
-		} else {
+		} elseif ( ! empty( $_SERVER['SCRIPT_NAME'] ) && false !== strpos( $_SERVER['SCRIPT_NAME'], '/wp-admin/plugins.php' ) ) {
 			add_option( 'Activated_Akismet', true );
 		}
 	}
@@ -1333,16 +1500,98 @@ p {
 		if ( $method !== 'pingback.ping' )
 			return;
 
+		// A lot of this code is tightly coupled with the IXR class because the xmlrpc_call action doesn't pass along any information besides the method name.
+		// This ticket should hopefully fix that: https://core.trac.wordpress.org/ticket/52524
+		// Until that happens, when it's a system.multicall, pre_check_pingback will be called once for every internal pingback call.
+		// Keep track of how many times this function has been called so we know which call to reference in the XML.
+		static $call_count = 0;
+
+		$call_count++;
+
 		global $wp_xmlrpc_server;
-	
+
 		if ( !is_object( $wp_xmlrpc_server ) )
 			return false;
-	
-		// Lame: tightly coupled with the IXR class.
-		$args = $wp_xmlrpc_server->message->params;
-	
-		if ( !empty( $args[1] ) ) {
-			$post_id = url_to_postid( $args[1] );
+
+		$is_multicall = false;
+		$multicall_count = 0;
+
+		if ( 'system.multicall' === $wp_xmlrpc_server->message->methodName ) {
+			$is_multicall = true;
+
+			if ( 0 === $call_count ) {
+				// Only pass along the number of entries in the multicall the first time we see it.
+				$multicall_count = count( $wp_xmlrpc_server->message->params );
+			}
+
+			/*
+			 * $wp_xmlrpc_server->message looks like this:
+			 *
+				(
+					[message] =>
+					[messageType] => methodCall
+					[faultCode] =>
+					[faultString] =>
+					[methodName] => system.multicall
+					[params] => Array
+						(
+							[0] => Array
+								(
+									[methodName] => pingback.ping
+									[params] => Array
+										(
+											[0] => http://www.example.net/?p=1 // Site that created the pingback.
+											[1] => https://www.example.com/?p=1 // Post being pingback'd on this site.
+										)
+								)
+							[1] => Array
+								(
+									[methodName] => pingback.ping
+									[params] => Array
+										(
+											[0] => http://www.example.net/?p=1 // Site that created the pingback.
+											[1] => https://www.example.com/?p=2 // Post being pingback'd on this site.
+										)
+								)
+						)
+				)
+			 */
+
+			// Use the params from the nth pingback.ping call in the multicall.
+			$pingback_calls_found = 0;
+
+			foreach ( $wp_xmlrpc_server->message->params as $xmlrpc_action ) {
+				if ( 'pingback.ping' === $xmlrpc_action['methodName'] ) {
+					$pingback_calls_found++;
+				}
+
+				if ( $call_count === $pingback_calls_found ) {
+					$pingback_args = $xmlrpc_action['params'];
+					break;
+				}
+			}
+		} else {
+			/*
+			 * $wp_xmlrpc_server->message looks like this:
+			 *
+				(
+					[message] =>
+					[messageType] => methodCall
+					[faultCode] =>
+					[faultString] =>
+					[methodName] => pingback.ping
+					[params] => Array
+						(
+							[0] => http://www.example.net/?p=1 // Site that created the pingback.
+							[1] => https://www.example.com/?p=2 // Post being pingback'd on this site.
+						)
+				)
+			 */
+			$pingback_args = $wp_xmlrpc_server->message->params;
+		}
+
+		if ( ! empty( $pingback_args[1] ) ) {
+			$post_id = url_to_postid( $pingback_args[1] );
 
 			// If pingbacks aren't open on this post, we'll still check whether this request is part of a potential DDOS,
 			// but indicate to the server that pingbacks are indeed closed so we don't include this request in the user's stats,
@@ -1355,23 +1604,30 @@ p {
 				$pingbacks_closed = true;
 			}
 
+			// Note: If is_multicall is true and multicall_count=0, then we know this is at least the 2nd pingback we've processed in this multicall.
+
 			$comment = array(
-				'comment_author_url' => $args[0],
+				'comment_author_url' => $pingback_args[0],
 				'comment_post_ID' => $post_id,
 				'comment_author' => '',
 				'comment_author_email' => '',
 				'comment_content' => '',
 				'comment_type' => 'pingback',
 				'akismet_pre_check' => '1',
-				'comment_pingback_target' => $args[1],
+				'comment_pingback_target' => $pingback_args[1],
 				'pingbacks_closed' => $pingbacks_closed ? '1' : '0',
+				'is_multicall' => $is_multicall,
+				'multicall_count' => $multicall_count,
 			);
 
-			$comment = Akismet::auto_check_comment( $comment );
+			$comment = self::auto_check_comment( $comment, 'xml-rpc' );
 
 			if ( isset( $comment['akismet_result'] ) && 'true' == $comment['akismet_result'] ) {
-				// Lame: tightly coupled with the IXR classes. Unfortunately the action provides no context and no way to return anything.
+				// Sad: tightly coupled with the IXR classes. Unfortunately the action provides no context and no way to return anything.
 				$wp_xmlrpc_server->error( new IXR_Error( 0, 'Invalid discovery target' ) );
+
+				// Also note that if this was part of a multicall, a spam result will prevent the subsequent calls from being executed.
+				// This is probably fine, but it raises the bar for what should be acceptable as a false positive.
 			}
 		}
 	}
@@ -1390,8 +1646,17 @@ p {
 		$meta_value = (array) $meta_value;
 
 		foreach ( $meta_value as $key => $value ) {
-			if ( ! isset( self::$comment_as_submitted_allowed_keys[$key] ) || ! is_scalar( $value ) ) {
-				unset( $meta_value[$key] );
+			if ( ! is_scalar( $value ) ) {
+				unset( $meta_value[ $key ] );
+			} else {
+				// These can change, so they're not explicitly listed in comment_as_submitted_allowed_keys.
+				if ( strpos( $key, 'POST_ak_' ) === 0 ) {
+					continue;
+				}
+
+				if ( ! isset( self::$comment_as_submitted_allowed_keys[ $key ] ) ) {
+					unset( $meta_value[ $key ] );
+				}
 			}
 		}