From f05943baaa060440e8cf103cc1603528d7303e33 Mon Sep 17 00:00:00 2001
From: Ryan Cramer <ryan@processwire.com>
Date: Thu, 14 Apr 2022 07:48:45 -0400
Subject: [PATCH] Add support in PagesPathFinder for default pagination prefix
 (pageNumUrlPrefix) even when overridden by default language setting in
 LanguageSupportPageNames module. Previously, it could potentially break
 pagination in some places (in admin) if you overrode the default language
 pagination prefix in that module.

---
 wire/core/PagesPathFinder.php | 59 +++++++++++++++++++++++++++++++++++
 1 file changed, 59 insertions(+)

diff --git a/wire/core/PagesPathFinder.php b/wire/core/PagesPathFinder.php
index ff55c3a1..7acd65d9 100644
--- a/wire/core/PagesPathFinder.php
+++ b/wire/core/PagesPathFinder.php
@@ -881,6 +881,11 @@ class PagesPathFinder extends Wire {
 			// redirect suggested
 			$response = 301;
 		}
+		
+		if($result['pageNum'] > 1 && ($response === 301 || $response === 302)) {
+			// redirect where pageNum is greater than 1
+			$response = $this->finishResultRedirectPageNum($response, $result);
+		}
 
 		if(empty($language['name'])) {
 			// set language property (likely for non-multi-language install)
@@ -1933,6 +1938,60 @@ class PagesPathFinder extends Wire {
 		}
 		return $path;
 	}
+	
+	
+	/*** ADDITIONAL/HELPER LOGIC ****************************************************************/
+	
+	/**
+	 * Update result for cases where a redirect was determined that involved pagination
+	 *
+	 * Most of the logic here allows for the special case of admin URLs, which work with either
+	 * a custom pageNumUrlPrefix or the original/default one. This is a helper for the
+	 * finishResult() method. 
+	 *
+	 * @param int $response
+	 * @var array $result
+	 * @return int
+	 * @since 3.0.198
+	 *
+	 */
+	protected function finishResultRedirectPageNum($response, &$result) {
+
+		if($result['pageNum'] < 2) return $response;
+
+		if(empty($result['page']['templates_id'])) return $response;
+		if($result['page']['status'] >= Page::statusUnpublished) return $response;
+
+		// The config[_pageNumUrlPrefix] property is set by LanguageSupportPageNames
+		$pageNumUrlPrefix = $this->wire()->config->get('_pageNumUrlPrefix');
+		if(empty($pageNumUrlPrefix)) $pageNumUrlPrefix = 'page';
+
+		// if default/original pageNum prefix not in use then do nothing further
+		if($result['pageNumPrefix'] !== $pageNumUrlPrefix) return $response;
+
+		// if request is not for something in the admin then do nothing further
+		$adminTemplate = $this->wire()->templates->get('admin');
+		if(!$adminTemplate || $result['page']['templates_id'] != $adminTemplate->id) return $response;
+
+		// request is for pagination within admin, where we allow either custom or original/default prefix
+		$requestParts = explode('/', trim($result['request'], '/'));
+		$redirectParts = explode('/', trim($result['redirect'], '/'));
+
+		$requestPrefix = array_pop($requestParts);
+		$redirectPrefix = array_pop($redirectParts);
+
+		$requestPath = implode('/', $requestParts);
+		$redirectPath = implode('/', $redirectParts);
+
+		// if something other than pagination prefix differs then do nothing further
+		if($requestPath != $redirectPath || $requestPrefix === $redirectPrefix) return $response;
+
+		// only the pagination prefix differs, allow it when in admin
+		$result['notes'][] = "Default pagination prefix '$pageNumUrlPrefix' allowed for admin template";
+		$response = 200;
+
+		return $response;
+	}
 
 }