From a545168ef25ef7a8309431329c8ed8920d9d6e9f Mon Sep 17 00:00:00 2001
From: Corey McKrill <916023+coreymckrill@users.noreply.github.com>
Date: Thu, 17 Mar 2022 15:07:30 -0700
Subject: [PATCH] Contributors: Prevent adding to a pledge twice.

This syncs `r17275-dotorg` to the canonical Git repo.
---
 plugins/wporg-5ftf/includes/contributor.php | 35 ++++++++++++++++++---
 plugins/wporg-5ftf/includes/endpoints.php   |  2 +-
 2 files changed, 32 insertions(+), 5 deletions(-)

diff --git a/plugins/wporg-5ftf/includes/contributor.php b/plugins/wporg-5ftf/includes/contributor.php
index ec0ae88..0008059 100644
--- a/plugins/wporg-5ftf/includes/contributor.php
+++ b/plugins/wporg-5ftf/includes/contributor.php
@@ -455,16 +455,27 @@ function process_my_pledges_form() {
  * Ensure each item in a list of usernames is valid and corresponds to a user.
  *
  * @param string $contributors A comma-separated list of username strings.
+ * @param int    $pledge_id    Optional. The ID of an existing pledge post that contributors are being added to.
  *
  * @return array|WP_Error An array of sanitized wporg usernames on success. Otherwise WP_Error.
  */
-function parse_contributors( $contributors ) {
+function parse_contributors( $contributors, $pledge_id = null ) {
 	$invalid_contributors   = array();
+	$duplicate_contributors = array();
 	$sanitized_contributors = array();
 
 	$contributors = str_replace( '@', '', $contributors );
 	$contributors = explode( ',', $contributors );
 
+	$existing_usernames = array();
+	if ( $pledge_id ) {
+		$pledge_contributors = get_pledge_contributors( $pledge_id, 'all' );
+		$existing_usernames  = wp_list_pluck(
+			$pledge_contributors['publish'] + $pledge_contributors['pending'],
+			'post_title'
+		);
+	}
+
 	foreach ( $contributors as $wporg_username ) {
 		$sanitized_username = sanitize_user( $wporg_username );
 		$user               = get_user_by( 'login', $sanitized_username );
@@ -474,16 +485,21 @@ function parse_contributors( $contributors ) {
 		}
 
 		if ( $user instanceof WP_User ) {
+			if ( in_array( $user->user_login, $existing_usernames, true ) ) {
+				$duplicate_contributors[] = $user->user_login;
+				continue;
+			}
+
 			$sanitized_contributors[] = $user->user_login;
 		} else {
 			$invalid_contributors[] = $wporg_username;
 		}
 	}
 
-	if ( ! empty( $invalid_contributors ) ) {
-		/* translators: Used between sponsor names in a list, there is a space after the comma. */
-		$item_separator = _x( ', ', 'list item separator', 'wporg-5ftf' );
+	/* translators: Used between sponsor names in a list, there is a space after the comma. */
+	$item_separator = _x( ', ', 'list item separator', 'wporg-5ftf' );
 
+	if ( ! empty( $invalid_contributors ) ) {
 		return new WP_Error(
 			'invalid_contributor',
 			sprintf(
@@ -494,6 +510,17 @@ function parse_contributors( $contributors ) {
 		);
 	}
 
+	if ( ! empty( $duplicate_contributors ) ) {
+		return new WP_Error(
+			'duplicate_contributor',
+			sprintf(
+				/* translators: %s is a list of usernames. */
+				__( 'The following contributor usernames are already associated with this pledge: %s', 'wporg-5ftf' ),
+				implode( $item_separator, $duplicate_contributors )
+			)
+		);
+	}
+
 	if ( empty( $sanitized_contributors ) ) {
 		return new WP_Error(
 			'contributor_required',
diff --git a/plugins/wporg-5ftf/includes/endpoints.php b/plugins/wporg-5ftf/includes/endpoints.php
index e6dea41..f51601c 100644
--- a/plugins/wporg-5ftf/includes/endpoints.php
+++ b/plugins/wporg-5ftf/includes/endpoints.php
@@ -55,7 +55,7 @@ function manage_contributors_handler() {
 
 		case 'add-contributor':
 			$pledge           = get_post( $pledge_id );
-			$new_contributors = Contributor\parse_contributors( $_POST['contributors'] );
+			$new_contributors = Contributor\parse_contributors( $_POST['contributors'], $pledge->ID );
 			if ( is_wp_error( $new_contributors ) ) {
 				wp_die( wp_json_encode( array(
 					'success' => false,