[tex4ht] tex4ht gives package amsmath error tag not allowed here

[Nasser M. Abbasi]

fyi, Just posted this error for tex4ht

https://tex.stackexchange.com/questions/383129/tex4ht-gives-package-amsmath-error-tag-not-allowed-here

Not sure if this is known or not? Should I create a bug report?

There was a related issue

https://puszcza.gnu.org.ua/bugs/?225

But it does not look they are same error, Or may be they are
the same?

Only when run with make4ht. No error with lualatex nor with pdflatex.
MWE:

---------------------
\documentclass[11pt]{article}
\usepackage{amsmath}

\begin{document}
\[
x=y \tag{1}
\]
\end{document}
-------------------------

>make4ht  foo.tex
.....
LaTeX2e <2017/01/01> patch level 3
Babel <3.9r> and hyphenation patterns for 83 language(s) loaded.
(./foo.tex (/usr/local/texlive/2016/texmf-dist/tex/latex/base/article.cls
Document Class: article 2014/09/29 v1.4h Standard LaTeX document class
(/usr/local/texlive/2016/texmf-dist/tex/latex/base/size11.clo))
....
(/usr/local/texlive/2016/texmf-dist/tex/generic/tex4ht/html4.4ht)
(/usr/local/texlive/2016/texmf-dist/tex/generic/tex4ht/html4-math.4ht))
(/usr/local/texlive/2016/texmf-dist/tex/generic/tex4ht/html4.4ht)
(/usr/local/texlive/2016/texmf-dist/tex/generic/tex4ht/html4-math.4ht))
(./foo.aux)

! Package amsmath Error: \tag not allowed here.

See the amsmath package documentation for explanation.
Type  H <return>  for immediate help.
  ...
l.7 x=y \tag
             {1}
?


which make4ht
/usr/local/texlive/2016/texmf-dist/scripts/make4ht/make4ht

I changed the code to use \begin{align} etc... and now tex4ht does
not complain about \tag any more

--Nasser