### patch.diff file:
```diff
--- a/components/com_remository/src/Controllers/Advsearch.php
+++ b/components/com_remository/src/Controllers/Advsearch.php
@@ -61,18 +61,28 @@
         }
         $noindex = true;
-        $classid = Utils::getRequestParam('id', '', 'string');
-        if ('' != $classid) {
+        $classid = Utils::getRequestParam('id', 0, 'string');
+        if ($classid) {
             if ('*' == $classid) {
                 if (!$search_text) {
                     $handler->setSearchText('');
                     $handler->removeClassify('*');
                 }
-            } elseif ($classid > 0) {
-                $handler->addClassify($classid);
-                if ('classify' == $func) {
-                    $noindex = false;
-                    $classification = $handler->getClassify($classid);
-                    if (is_object($classification)) {
-                        $this->interface->setPageTitle($classification->name);
+            } else {
+                $classidnum = intval($classid);
+                if ($classidnum > 0) {
+                    $handler->addClassify($classidnum);
+                    if ('classify' == $func) {
+                        $noindex = false;
+                        $classification = $handler->getClassify($classidnum);
+                        if (is_object($classification)) {
+                            $this->interface->setPageTitle($classification->name);
+                        }
                     }
+                } elseif ($classidnum < 0) {
+                    $handler->removeClassify(-$classidnum);
                 }
-            } elseif ($classid < 0)
-                $handler->removeClassify(-$classid);
+            }
         }

--- a/components/com_remository/src/Managers/ClassificationManager.php
+++ b/components/com_remository/src/Managers/ClassificationManager.php
@@ -XXX,7 +XXX,8 @@
     public function addClassify($id) {
         if (('*' == $id OR !is_null($this->getType(intval($id)))) AND !in_array($id, $this->userstuff['clstack'])) {
             array_push($this->userstuff['clstack'], $id);
             if ('*' != $id) {
-                Utils::doSQL("UPDATE #__downloads_classify SET frequency=frequency+1 WHERE id=$id");
+                $idnum = intval($id);
+                Utils::doSQL("UPDATE #__downloads_classify SET frequency=frequency+1 WHERE id=$idnum");
             }
         }
     }