force_balance_tags not properly balancing < with <strong> and </strong>

[jpmerx]

Given following HMTL code which includes the \[ and \] Latex delimiters:

\[<\] <strong>We</strong>

the output of force_balance_tags is

\[<\] <strong>We

which is not correct as the bold tags are unbalanced. Expected output should be the input string.

[jpmerx]

I found an even simple string producing the error.

For following HMTL code which includes the < symbol:

< <strong>We</strong>

the output of force_balance_tags is

< <strong>We

which is not correct as the bold tags are unbalanced. Expected output should be the input string.

[dmsnell]

@jpmerx I'm looking at replacing the internal logic of force_balance_tags() to rely on the new WP_HTML_Processor::normalize() method. That seems to resolve these issues.

<?php
echo force_balance_tags( '\[<\] <strong>We</strong>' );
// \[&lt;\] <strong>We</strong>

echo force_balance_tags( '< <strong>We</strong>' );
// &lt; <strong>We</strong>

​https://github.com/WordPress/wordpress-develop/pull/7409