[Mailman2Bridge] fix message separation and improve "From_ lines" dis…

…ambiguation (#4156)

* [Mailman2Bridge.php] enable PCRE_MULTILINE pattern modifier

Enable PCRE_MULTILINE pattern modifier on mbox content parsing. Without it parsing monthly archives results in only a single message each.

* [Mailman2Bridge.php] extend mbox "From_ lines" pattern

Extend PCRE pattern matching individual "From_ lines" used to split single messages in mbox content. 

In addition to the matching line having to start with 'From ' it now also has to end with time and date (hh:mm:ss yyyy). 

This makes the pattern slightly more robust against accidental matches when a line within the actual message body starts with 'From ' which Mailman 2 (Pipermail) may not be configured to disambiguate.

* [Mailman2Bridge.php] remove trailing slash from URI constant

---------

Co-authored-by: enwu <[email protected]>

bridges/Mailman2Bridge.php

@@ -3,7 +3,7 @@
 class Mailman2Bridge extends BridgeAbstract
 {
     const NAME = 'Mailman2Bridge';
-    const URI = 'https://list.org/';
+    const URI = 'https://list.org';
     const MAINTAINER = 'imagoiq';
     const CACHE_TIMEOUT = 60 * 30; // 30m
     const DESCRIPTION = 'Fetch latest messages from Mailman 2 archive (Pipermail)';
@@ -68,7 +68,7 @@ public function collectData()
                     throw new \Exception('Failed to gzdecode');
                 }
             }
-            $mboxParts = preg_split('/^From /', $data);
+            $mboxParts = preg_split('/^From\s.+\d{2}:\d{2}:\d{2}\s\d{4}$/m', $data);
             // Drop the first element which is always an empty string
             array_shift($mboxParts);
             $mboxMails = array_reverse($mboxParts);