Convert recentTrackers->last_used to an array (#2783)

Previously, we were storing a string, and if a user created 20 torrents
in a row, it would add 20 trailing carriage returns (\r) to the	box.

We already do the logic	of stripping empty lines for other purposes,
lets reuse that here.

Add de-duplication of last used trackers (to match the list array).

Also eliminate $announce_list, because it's never used, and `grep -rn announce_list * | grep global`
indicates no other function is using it without it being passed.

plugins/create/action.php

@@ -10,7 +10,7 @@ class recentTrackers
 	public $hash = "rtrackers.dat";
 	public $modified = false;
 	public $list = array();
-	public $last_used = "";
+	public $last_used = array();
 	public $piece_size = 1024;
 	public $start_seeding = false;
 	public $private_torrent = false;
@@ -21,6 +21,14 @@ static public function load()
 		$cache = new rCache();
 		$rt = new recentTrackers();
 		$cache->get($rt);
+
+		// TODO: Temporary migration from string to array
+		// Can remove this after November 2026
+		if (is_string(($rt->last_used)))
+		{
+			$rt->last_used = [];
+		}
+
 		return($rt);
 	}
 	public function store()
@@ -51,6 +59,7 @@ public function get()
 	public function strip()
 	{
 		global $recentTrackersMaxCount;
+		$this->last_used = array_values( array_unique($this->last_used) );
 		$this->list = array_values( array_unique($this->list) );
 		$cnt = count($this->list);
 		$arr = array_values($this->list);
@@ -131,38 +140,29 @@ static public function getTrackerDomain($announce)
 				{
 					$rt = recentTrackers::load();
 					$trackers = array();
-					$announce_list = '';
 					if(isset($_REQUEST['trackers']))
 					{
-						$rt->last_used = $_REQUEST['trackers'];  // remember trackers last used
-						$arr = explode("\r",$_REQUEST['trackers']);
+						$arr = explode("\r", $_REQUEST['trackers']);
 						foreach( $arr as $key => $value )
 						{
 							$value = trim($value);
-							if(strlen($value))
+							if(strlen($value) === 0)
 							{
-								$trackers[] = $value;
-								$rt->list[] = $value;
-							}
-							else
-							{
-								if(count($trackers)>0)
-								{
-									$announce_list .= (' -a '.escapeshellarg(implode(',',$trackers)));
-									$trackers = array();
-								}
+								continue;
 							}
+
+							$trackers[] = $value;
+							$rt->list[] = $value;
 						}
 					}
 					// remember checkbox and dropdown options
+					$rt->last_used = $trackers;
 					$rt->piece_size = $_REQUEST['piece_size'];
 					$rt->start_seeding = $_REQUEST['start_seeding'];
 					$rt->private_torrent = $_REQUEST['private'];
 					$rt->hybrid_torrent = $_REQUEST['hybrid'];
 					$rt->store();
 
-					if(count($trackers)>0)
-						$announce_list .= (' -a '.escapeshellarg(implode(',',$trackers)));
 					$piece_size = 262144;
 					if(isset($_REQUEST['piece_size']))
 						$piece_size = $_REQUEST['piece_size']*1024;

plugins/create/init.js

@@ -226,7 +226,7 @@ plugin.onLangLoaded = function() {
 		theDialogManager.setHandler("tcreate", "beforeShow", () => {
 			if (plugin.recentTrackers) {
 				const recent = plugin.recentTrackers;
-				$("#trackers").val(recent.last_used);
+				$("#trackers").val(recent.last_used.join("\r\n"));
 				$(`#piece_size option[value=${recent.piece_size || 1024}]`).prop("selected", true);
 				$("#start_seeding").prop("checked", iv(recent.start_seeding));
 				$("#private").prop("checked", iv(recent.private_torrent));