[tex4ht] issue with raw html output with httex

[Michal Hoftich]

>No problem.  We'll try to adapt to that.

If you could post a complete example that used to work in the past, we 
can try to find if this is a regression and when it was introduced. We 
don't get much requests for texinfo support, so it could go unnoticed 
for quite some time.

I fixed two issues related to Plain TeX thanks to your request, so 
thanks for your report.

Best regards,
Michal