return 0 from get_body_length before loading the body to DomDocument if body is empty

showmore/showmore.php

@@ -69,10 +69,15 @@ function showmore_addon_settings_post(&$a,&$b) {
 function get_body_length($body) {
 	$string = trim($body);
 
+	// DomDocument doesn't like empty strings
+	if(! strlen($string)) {
+		return 0;
+	}
+
 	// We need to get rid of hidden tags (display: none)
 
 	// Get rid of the warning. It would be better to have some valid html as input
-	$dom = @DomDocument::loadHTML($body);
+	$dom = DomDocument::loadHTML($body);
 	$xpath = new DOMXPath($dom);
 
 	/*