Not valid striptags result, if summary is sliced

[if1live]

bug description

1. if summary text is...

blah...blah...blah....<a href="http://pythonhosted.org/openpyxl/">openpyxl</a>

I assume length of sample text is 220.

1. apply article.summary[:200]

blah...blah...blah....<a href="http://pythonhosted.org/ope

1. apply striptags

blah...blah...blah....<a href="http://pythonhosted.org/ope

FAILED

How to fix?

apply striptags to full content, then slice.

- article.summary[:200]|striptags 
+ article.summary|striptags|truncate(200)