From 150683e1a747e1b73bc8905ca084865b244eda67 Mon Sep 17 00:00:00 2001
From: Aaron Parecki <aaron@parecki.com>
Date: Fri, 12 Jan 2018 12:34:56 -0800
Subject: [PATCH] fix error when mailto links are encountered

---
 lib/helpers.php | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/lib/helpers.php b/lib/helpers.php
index d3a503f..8a90a9c 100644
--- a/lib/helpers.php
+++ b/lib/helpers.php
@@ -11,7 +11,8 @@ function normalize_url($url) {
   $parts = parse_url($url);
   if(empty($parts['path']))
     $parts['path'] = '/';
-  $parts['host'] = strtolower($parts['host']);
+  if(isset($parts['host']))
+    $parts['host'] = strtolower($parts['host']);
   return build_url($parts);
 }