Masonry & Magazine shortcodes bugs

Hi,

I found a strange behavior about the masonry & magazine shortcades.
If there is no breakpoint, but some tags in our pages, both the masonry blog & magazine shorcodes will show the whole post contents.

So I traced the shortcodes and found that function avia_backend_truncate() is the cause of the problem.
This function didn’t treat the situation if there is no breakpoint and exists some tags

I’ve these codes in functions.php of my enfold-child

// modify masonry excerpt length
add_filter( 'avf_masonry_excerpt_length', 'avf_masonry_excerpt_length_mod');
function avf_masonry_excerpt_length_mod() {
	$excerpt = 30;
	return $excerpt;
}

// modify magazine excerpt length
add_filter( 'avf_magazine_excerpt_length', 'avf_magazine_excerpt_length_mod');
function avf_magazine_excerpt_length_mod() {
	$excerpt = 40;
	return $excerpt;
}

// modify magazine delimiter <!--magazine-->
add_filter( 'avf_magazine_excerpt_delimiter', 'avf_magazine_excerpt_delimiter_mod');
function avf_magazine_excerpt_delimiter_mod() {
	$break = "<!--magazine-->";
	return $break;
}

// modify masonry delimiter <!--masonry-->
add_filter( 'avf_masonry_excerpt_delimiter', 'avf_masonry_excerpt_delimiter_mod');
function avf_masonry_excerpt_delimiter_mod() {
	$break = "<!--masonry-->";
	return $break;
}

// excerpt truncate function modified for Chinese
function avia_backend_truncate($string, $limit, $break=".", $pad="...", $stripClean = false, $excludetags = '<strong><em><span>', $safe_truncate = false)
{

	if(strlen($string) <= $limit) return $string;

	// if exists $breakpoint
	if(false !== ($breakpoint = strpos($string, $break)))
	{
		if($breakpoint < strlen($string) - 1)
		{
                    	$string = substr($string, 0, $breakpoint) . $pad;
             	}
	} 
	// if no $breakpoint
	else
	{
                $string = wp_trim_words($string, $limit) ;
	}

	// strip unwanted HTML tags
	if($stripClean)
	{
		$string = strip_shortcodes(strip_tags($string, $excludetags));
	}

	return $string;
}

I moved the [//strip unwanted HTML tags] part to the last, because it will strip the breakpoint like <!–magazine–>, <!–masonry–> and <!–more–>.
And I use wp_trim_words() function to avoid some problems in Chinese words.

There is a post about the wordpress excerpt problem for Chinese,
http://wptutorial.narrativecard.com/wordpress-excerpt-problem-chinese/