Actually, I get the impression from the OP that sundialsvc4
is using something that automatically transforms two (or more?) consecutive spaces into a single space followed by one (or more?)
(it must be automatic, because doing it manually is too painful to contemplate). And I wouldn't be surprised if the same mechanism does something about changing line breaks into <p>
I'll just mention that when editing human-readable text in emacs (as I often do when documenting the code I write), I've developed a habit of putting two spaces (not one) between a period and the next word, because if I don't do that, emacs' line-wrap strategy won't allow a line break after that period. It's weird, but there is a traditional "rule of style", dating back to the days of typewriters and fixed-width-font printers, that mandated two spaces at every sentence boundary inside a paragraph.
(Who remembers that cover art for an issue of the Perl Journal, showing the start of a perl installation log on an Underwood typewriter? That one was my all-time favorite.)