devel/pear-Horde_Core: fix error messages

Patch submitted by wahnes (at) uni-koeln (dot) de.

PR:		267508
Approved by:	maintainer’s time-out
Obtained from:	https://bugs.horde.org/ticket/15093

devel/pear-Horde_Core/Makefile

@@ -1,5 +1,6 @@
 PORTNAME=	Horde_Core
 DISTVERSION=	2.31.16
+PORTREVISION=	1
 CATEGORIES=	devel www pear
 
 MAINTAINER=	horde@FreeBSD.org

devel/pear-Horde_Core/files/patch-lib_Horde_Themes_Element.php

@@ -0,0 +1,11 @@
+--- lib/Horde/Themes/Element.php.orig	2020-09-06 03:24:25 UTC
++++ lib/Horde/Themes/Element.php
+@@ -143,7 +143,7 @@ class Horde_Themes_Element
+         switch ($name) {
+         case 'fs':
+         case 'uri':
+-            return $this->_data[$name];
++            return (isset($this->_data[$name])) ? $this->_data[$name] : null;
+ 
+         case 'fulluri':
+             return Horde::url($this->_data['uri'], true);