[PHP-WEBMASTER] [web-news] master: Fix handling of missing parent messages in `ThreadTree`

[Tim Düsterhus via Derick Rethans]

Author: Tim Düsterhus (TimWolla)
Committer: Derick Rethans (derickr)
Date: 2026-03-09T16:14:57-04:00

Commit: 
https://github.com/php/web-news/commit/65aa28903719172c6fae3957248533b5a8cebff5
Raw diff: 
https://github.com/php/web-news/commit/65aa28903719172c6fae3957248533b5a8cebff5.diff

Fix handling of missing parent messages in `ThreadTree`

The logic to correctly associate messages where the parent message is not in
the archives already existed by means of `ThreadTree::$extraRootChildren`,
however the “extra root” threads were not correctly printed, because
`printThread()` required the message at the root of the thread to exist.

Fix this by printing a placeholder “Unknown message” for unknown messageIds and
then printing the children as usual.

Fixes php/web-php#35

Changed paths:
  M  lib/ThreadTree.php


Diff:

diff --git a/lib/ThreadTree.php b/lib/ThreadTree.php
index 06e4434..399cac5 100644
--- a/lib/ThreadTree.php
+++ b/lib/ThreadTree.php
@@ -133,16 +133,14 @@ public function printThread(
             return;
         }
 
-        if (array_key_exists($messageId, $this->articleNumbers)) {
-            $articleNumber = $this->articleNumbers[$messageId];
 
-            # for debugging that we've actually handled all articles
-            #unset($this->articleNumbers[$messageId]);
+        # for debugging that we've actually handled all articles
+        #unset($this->articleNumbers[$messageId]);
 
-            $details = $this->articles[$articleNumber];
-
-            echo '<li>';
+        echo '<li>';
 
+        if (array_key_exists($messageId, $this->articleNumbers)) {
+            $articleNumber = $this->articleNumbers[$messageId];
             $details = $this->articles[$articleNumber];
 
             if ($articleNumber != $activeArticleNumber) {
@@ -172,23 +170,26 @@ public function printThread(
             } else {
                 echo "</b>";
             }
+        } else {
+            echo "<i>Unknown Message</i>";
+            $newSubject = $messageId;
+        }
 
-            if (array_key_exists($messageId, $this->tree)) {
-                echo '<ul>';
-                foreach ($this->tree[$messageId] as $childMessageId) {
-                    $this->printThread(
-                        group: $group,
-                        activeArticleNumber: $activeArticleNumber,
-                        messageId: $childMessageId,
-                        subject: $newSubject,
-                        charset: $charset,
-                        depth: $depth + 1,
-                    );
-                }
-                echo '</ul>';
+        if (array_key_exists($messageId, $this->tree)) {
+            echo '<ul>';
+            foreach ($this->tree[$messageId] as $childMessageId) {
+                $this->printThread(
+                    group: $group,
+                    activeArticleNumber: $activeArticleNumber,
+                    messageId: $childMessageId,
+                    subject: $newSubject,
+                    charset: $charset,
+                    depth: $depth + 1,
+                );
             }
-
-            echo "</li>";
+            echo '</ul>';
         }
+
+        echo "</li>";
     }
 }