Don't delete existing downloads

lib/update_downloads.php

@@ -3,15 +3,30 @@
 
 define("SITE_ROOT", realpath(dirname(__file__) . "/.."));
 require_once SITE_ROOT . "/lib/init.php";
+
+function get_downloads()
+{
+  global $DB;
+
+  $ret = array();
+
+  if (!$res = $DB->query("select file_name from downloads")) return;
+
+  while ($row = $DB->fetchRow($res)) {
+    $ret[] = $row["file_name"];
+  }
+
+  return $ret;
+}
+
+$all_downloads = get_downloads();
 $sync = array("bz2", "log", "exe", "dmg");
 
-$DB->query("begin");
-$DB->query("delete from downloads");
 
 if ($dh = opendir(SITE_ROOT)) {
   while (($file = readdir($dh)) !== false) {
     $ext = pathinfo($file, PATHINFO_EXTENSION);
-    if (in_array($ext, $sync)) {
+    if (in_array($ext, $sync) && !in_array($file, $all_downloads)) {
       $q = kl_str_sql("insert into downloads(file_name) values (!s)", $file);
       $DB->query($q);
     }
@@ -19,4 +34,4 @@ if ($dh = opendir(SITE_ROOT)) {
   closedir($dh);
 }
 
-$DB->query("commit");
+