refs #6661 also return HTTP 400 when idsite is 0

core/Tracker/Request.php

@@ -12,6 +12,7 @@ use Exception;
 use Piwik\Common;
 use Piwik\Config;
 use Piwik\Cookie;
+use Piwik\Exception\UnexpectedWebsiteFoundException;
 use Piwik\IP;
 use Piwik\Network\IPUtils;
 use Piwik\Piwik;
@@ -390,7 +391,7 @@ class Request
         Piwik::postEvent('Tracker.Request.getIdSite', array(&$idSite, $this->params));
 
         if ($idSite <= 0) {
-            throw new Exception('Invalid idSite: \'' . $idSite . '\'');
+            throw new UnexpectedWebsiteFoundException('Invalid idSite: \'' . $idSite . '\'');
         }
 
         return $idSite;

tests/PHPUnit/System/TrackerTest.php

@@ -77,4 +77,12 @@ class TrackerTest extends SystemTestCase
         $this->assertResponseCode(400, $url);
     }
 
+    public function test_response_ShouldSend400ResponseCode_IfSiteIdIsZero()
+    {
+        $url = $this->tracker->getUrlTrackPageView('Test');
+        $url .= '&idsite=0';
+
+        $this->assertResponseCode(400, $url);
+    }
+
 }