Html sanitizer doesn't add missing closing tags

[Jun Omae]

The html sanitizer adds missing closing tags in Trac 1.0.20, but doesn't in Trac 1.6. It can result that the output is not well-formed fragment.

See also: #13589

Trac 1.6

>>> import trac
>>> trac.__version__
'1.6'
>>> from trac.test import EnvironmentStub, MockRequest
>>> from trac.web.chrome import web_context
>>> from trac.wiki.formatter import format_to_html
>>> env = EnvironmentStub()
>>> req = MockRequest(env)
>>> context = web_context(req)
>>> format_to_html(env, context, u"""{{{#!html
... <div>
... <p>foo</p>
... }}}
... """)
Markup('<div>\n<p>foo</p>\n')

Trac 1.0.20

>>> import trac
>>> trac.__version__
'1.0.20'
>>> from trac.test import EnvironmentStub, MockRequest
>>> from trac.web.chrome import web_context
>>> from trac.wiki.formatter import format_to_html
>>> env = EnvironmentStub()
>>> req = MockRequest(env)
>>> context = web_context(req)
>>> format_to_html(env, context, u"""{{{#!html
... <div>
... <p>foo</p>
... }}}
... """)
<Markup u'<div>\n<p>foo</p>\n</div>'>