Broken links in generated HTML code

[hpreusse]

I noticed that the generated HTML code contains broken symlinks, in case a hashtag is referenced. For example:
href="index.html#GoingfurtherOthertools.html" >up</a>] in GoingfurtherOthertools.html. The hashtag GoingfurtherOthertools.html does not exist in the index.html.
I tried to build a mininal example, which tries to reduce the document to the relevant part, it is attached. The error is visible in the full document too. I did not check if we look at an issue in tex4ht or your project.
MWE_broken_links.tar.gz