From 564ab6b78f89810c1b9fe4e81888fed66e56108c Mon Sep 17 00:00:00 2001
From: justme1968 <justme1968@2b470e98-0d58-463d-a4d8-8e2adae1ed80>
Date: Sat, 18 Oct 2014 19:28:13 +0000
Subject: [PATCH] readingsHistory: fixed regex warning

git-svn-id: svn://svn.code.sf.net/p/fhem/code/trunk@6788 2b470e98-0d58-463d-a4d8-8e2adae1ed80
---
 fhem/FHEM/33_readingsHistory.pm | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fhem/FHEM/33_readingsHistory.pm b/fhem/FHEM/33_readingsHistory.pm
index 723e45991..3fb8da6fb 100644
--- a/fhem/FHEM/33_readingsHistory.pm
+++ b/fhem/FHEM/33_readingsHistory.pm
@@ -237,7 +237,7 @@ readingsHistory_2html($)
 
   return undef if( !$hash );
 
-  if( $hash->{DEF} =~ m/=/ ) {
+  if( $hash->{DEF} && $hash->{DEF} =~ m/=/ ) {
     if( !$hash->{fhem}->{last_update}
         || gettimeofday() - $hash->{fhem}->{last_update} > 600 ) {
       readingsHistory_updateDevices($hash);