encodeForHTMLAttribute does not encode space character

[GoogleCodeExporter]

$ESAPI.encoder().encodeForHTMLAttribute(' ') should return   as space 
character is not in present in IMMUNE_HTMLATTR

This could cause breakage in HTML Attribute

Ex:
document.getElementByID("test").innerHTML="<div 
data="+$ESAPI.encoder().encodeForHTMLAttribute('test xyz')+">This is a 
test</div>";

Would result in the following HMTL content

<div data="test" xyz="">This is a test</div>

Original issue reported on code.google.com by [email protected] on 23 Jul 2015 at 6:45