TYPO3 Core

The PageRouter already overrides the decoded page's uid with the l10n_parent if it exists.
See \TYPO3\CMS\Core\Routing\PageRouter::buildPageArguments()

The same logic exists also in \TYPO3\CMS\Core\Routing\PageSlugCandidateProvider::getRealPageIdForPageIdAsPossibleCandidate() and \TYPO3\CMS\Core\Routing\PageSlugCandidateProvider::getPagesFromDatabaseForCandidates().

Maybe the PageSlugCandidateProvider should be fixed in order to always return the live uid of the page.

Fix proposal

The PageSlugCandidateProvider should be fixed to return the live uid of the record (if exists), the versionOL will be done later in the request handling (TSFE->determineId).

The page record is actually loaded with the requested slug, and with language and workspace restrictions.
Then, mountpage logic is applied, in which versionOL is done.

I propose to fix the uid of the loaded record if it is a draft record.
A very rough fix could be:

--- a/Classes/Routing/PageSlugCandidateProvider.php    2020-12-22 07:59:57.000000000 +0100
+++ b/Classes/Routing/PageSlugCandidateProvider.php    2020-12-31 16:38:24.123223188 +0100
@@ -136,7 +136,13 @@
         if (empty($page)) {
             return null;
         }
-        return (int)($page['l10n_parent'] ?: $page['uid']);
+
+        $pageIdInDefaultLanguage = (int)($page['l10n_parent'] ?: $page['uid']);
+        if ($liveRowId = \TYPO3\CMS\Backend\Utility\BackendUtility::getLiveVersionIdOfRecord('pages', $pageIdInDefaultLanguage)) {
+            return $liveRowId;
+        }
+
+        return $pageIdInDefaultLanguage;
     }

     /**
@@ -230,6 +236,11 @@
         $isRecursiveCall = !empty($excludeUids);

         while ($row = $statement->fetch()) {
+            if ($liveRowId = \TYPO3\CMS\Backend\Utility\BackendUtility::getLiveVersionIdOfRecord('pages', $row['uid'])) {
+                $row['_ORIG_uid'] = $row['uid'];
+                $row['uid'] = $liveRowId;
+            }
+
             $mountPageInformation = null;
             // This changes the PID value and adds a _ORIG_PID value (only different in move actions)
             // In live: This fetches everything in a bad way ! as there is no workspace limitation given, fetching all new and moved placeholders here!

To be discussed, especially the way l10n_parent should be handled in case l10n_parent point to a draft version (whenever this is possible?)

Hey,

the link should be generated with the live ID already, this is how TYPO3 Core handles this everywhere. Otherwise we'd need to do another loop + query on each request to check if this is a versioned record (I guess we still need to do this)...

Hey Benni

According to what I wrote last year, the live ID is properly used when generating the link.
The "issue" is more when decoding the url: the draft ID is used there, and fails to validate the cHash.