Index: typo3/sysext/felogin/pi1/class.tx_felogin_pi1.php
===================================================================
--- typo3/sysext/felogin/pi1/class.tx_felogin_pi1.php	(revision 8471)
+++ typo3/sysext/felogin/pi1/class.tx_felogin_pi1.php	(working copy)
@@ -632,13 +632,8 @@
 			return '';
 		}
 
-		if (!t3lib_div::isValidUrl($sanitizedUrl)) {
-			t3lib_div::sysLog(sprintf($this->pi_getLL('noValidRedirectUrl'), $sanitizedUrl), 'felogin', t3lib_div::SYSLOG_SEVERITY_WARNING);
-			return '';
-		}
-
 			// Validate the URL:
-		if ($this->isInCurrentDomain($sanitizedUrl) || $this->isInLocalDomain($sanitizedUrl)) {
+		if ($this->isRelativeUrl($sanitizedUrl) || $this->isInCurrentDomain($sanitizedUrl) || $this->isInLocalDomain($sanitizedUrl)) {
 			return $sanitizedUrl;
 		}
 
@@ -655,43 +650,61 @@
 	 * @return boolean Whether the URL belongs to the current TYPO3 installation
 	 */
 	protected function isInCurrentDomain($url) {
-		return (t3lib_div::isOnCurrentHost($url) && strpos($url, t3lib_div::getIndpEnv('TYPO3_SITE_URL')) === 0);
+		return (t3lib_div::isOnCurrentHost($url) AND t3lib_div::isFirstPartOfStr($url, t3lib_div::getIndpEnv('TYPO3_SITE_URL')));
 	}
 
 	/**
 	 * Determines whether the URL matches a domain
 	 * in the sys_domain databse table.
 	 *
-	 * @param string $domain Name of the domain to be looked up
-	 * @return boolean Whether the domain name is considered to be local
+	 * @param string $url Absolute URL which needs to be checked
+	 * @return boolean Whether the URL is considered to be local
 	 */
 	protected function isInLocalDomain($url) {
 		$result = FALSE;
+		
+		if (t3lib_div::isValidUrl($url)) {
+			$parsedUrl = parse_url($url);
+				// Removes the last path segment and slash sequences like /// (if given):
+			$path = preg_replace('#/+[^/]*$#', '', $parsedUrl['path']);
 
-		$parsedUrl = parse_url($url);
-		$domain = $parsedUrl['host'] . $parsedUrl['path'];
+			$localDomains = $GLOBALS['TYPO3_DB']->exec_SELECTgetRows(
+				'domainName',
+				'sys_domain',
+				'1=1' . $this->cObj->enableFields('sys_domain')
+			);
 
-		$localDomains = $GLOBALS['TYPO3_DB']->exec_SELECTgetRows(
-			'domainName',
-			'sys_domain',
-			'1=1' . $this->cObj->enableFields('sys_domain')
-		);
-
-		if (is_array($localDomains)) {
-			foreach ($localDomains as $localDomain) {
-				if (stripos($domain, $localDomain['domainName']) === 0) {
-					$result = TRUE;
-					break;
+			if (is_array($localDomains)) {
+				foreach ($localDomains as $localDomain) {
+						// strip trailing slashes (if given)
+					$domainName = rtrim($localDomain['domainName'], '/');
+					if (t3lib_div::isFirstPartOfStr($host. $path . '/', $domainName . '/')) {
+						$result = TRUE;
+						break;
+					}
 				}
 			}
 		}
-
 		return $result;
 	}
+
+	/**
+	 * Determines wether the URL is relative to the
+	 * current TYPO3 installation.
+	 *
+	 * @param string $url URL which needs to be checked
+	 * @return boolean Whether the URL is considered to be relative
+	 */
+	protected function isRelativeUrl($url) {
+		$parsedUrl = @parse_url($url);
+		if ($parsedUrl !== FALSE && !isset($parsedUrl['scheme']) && !isset($parsedUrl['host'])) {
+				// If the relative URL starts with a slash, we need to check if it's within the current site path
+			return (!t3lib_div::isFirstPartOfStr($parsedUrl['path'], '/') || t3lib_div::isFirstPartOfStr($parsedUrl['path'], t3lib_div::getIndpEnv('TYPO3_SITE_PATH')));
+		}
+		return FALSE;
+	}
 }
 
-
-
 if (defined('TYPO3_MODE') && $TYPO3_CONF_VARS[TYPO3_MODE]['XCLASS']['ext/felogin/pi1/class.tx_felogin_pi1.php'])	{
 	include_once($TYPO3_CONF_VARS[TYPO3_MODE]['XCLASS']['ext/felogin/pi1/class.tx_felogin_pi1.php']);
 }