Php error when variable doesn't exist in data

I'm using Lightncandy without since last January without any problems but after upgrade to v.10
got some php errors when trying to use a variable that does not exists in the data.

After make one change in getVariableName fixed it, maybe. What do you think? 

How to reproduce:
template:
{{#if var_1}}
  Var_1 value: {{{var_1}}}
{{/if}}
{{#if var_2}}
  Var_2 value: {{{var_2}}}
{{/if}}

$test_data      = array ('var_1' => 'Hello', 'var_2' => 'world!');
$test_data_error = array ('var_1' => 'Hello');

Compile options:

$lightnCandy_flags =
LightnCandy::FLAG_ERROR_LOG 
| LightnCandy::FLAG_HANDLEBARSJS
| LightnCandy::FLAG_ERROR_EXCEPTION
| LightnCandy::FLAG_EXTHELPER
;