Curly braces in a conditional with a regex throws parsing error

[litzinger]

Description of the problem
Using curly braces in a regex comparison in a conditional causes a parsing error. I have a situation where I need to detect if a segment is a valid ISO code, e.g. en-us, or ca-fr. It appears as if the conditional parser is choking on the curly braces in the regex, b/c as soon as they are removed the error message goes away, but of course the regex isn't matching what I need it to match.

How To Reproduce
Steps to reproduce the behavior:
Add the following to a template file, and it'll yield the error message below.
{if segment_2 ~ "/\S{2}-\S{2}/"}{/if}

Error Messages

You have an invalid conditional in your template. Please review your conditionals for an unclosed string, invalid operators, a missing }, or a missing {/if}.

Environment Details:

• Version: 4.3.6
• PHP Version: 7.1
• MySQL Version: 5.7
• OS: Linux (via Vagrant)
• Web Server: Apache

[derekjones]

I haven't confirmed this report yet, but as a workaround you should be able to use '/\S\S-\S\S/'.

[litzinger]

I actually converted to using Resource Router as it was easier to handle 4 url variations the same template, and keep this sort of logic out of the template file.