problem with single quote in input field

Are you expecting a problem? What is the problem? Please clarify.

If fact if I use form_input() it's not working. I get test'test in the input form
If I not use form input I get the correct text in my input field test'test

exemple :

I can replace this
$a="test'test";
$field=array('type'=>'text', 'name'=>'test','value'=>set_value($a), 'size'=>'64','maxsize'=>'255');
echo form_input($field);
By
$a="test'test";
$b=set_value('test',$a);
echo '<input type="text" name="test" value="'.$b.'" size="64" maxsize="255">';
And it's working,

But why I can't use form_input(); it's a bug ?