(Split from bug 89069; description pasted from there and modified accordingly.)

I know this goes back to at least Writer 4.2.1.1, but I can't speak to earlier versions, although I suspect that, like bug 89069, it traces back to OOo. I use LibreOffice Writer to create/edit documents as ODT files, then "Save a Copy" with "HTML Document (Writer)" to export an HTML copy, which is intended for use in an XHTML environment. (The "Export as XHTML" code is far messier and harder to clean up, but I should note that it does NOT exhibit this behavior. Hence, it is most likely a save-as-HTML filter issue rather than a Writer bug.) Furthermore, if it matters, I am using smart quotes and UTF-8 encoding.

When using Save a Copy > HTML to create an HTML version of a Writer document, the saved HTML contains hard line breaks within block-level elements - that is, it manually wraps the output, rather than reserving line breaks for semantically and/or syntactically significant situations (i.e. between paragraphs, after META elements). An enhancement to the HTML save filter to allow user configuration of that behavior (no breaks, wrapped lines, smart breaks) would be rather helpful.

Note that "Save a Copy > HTML" breaks at every line, but "Export... > XHTML" has no breaks. I'm advocating an option in between, on the principle that it is easier for a user to insert every-line wrapping than to correctly remove it, but that breaks between paragraphs, headers, and other block-level elements are useful. Further, when the output code needs to be touched up, it is much easier to perform search/replace operations on unwrapped lines than wrapped ones, and also much safer when one knows that a search won't accidentally cross paragraph borders.