[kovidgoyal]

@Hitch: Again, the only time HTML is automatically corrected is if you run one of the automated tools, like smarten punctuation or Fix HTML or rename files and so on. This has to be done, because the automated tools have to be able to parse and modify the HTML, which means auto-fixing it.

If all you do is open an html file, edit it, click save, the only automated change that happens is conversion of HTML entities to their unicode characters. The HTML itself is not touched. Therefore, if you want to make sure that no automated changes happen, simply ensure all your HTML is parseable XML before running any automated tool.

Finally, there will be an error check tool that will tell you about unparseable XML in the book, along with other useful (as opposed to the junk produced by epubcheck) errors.