The earlier fix covered the Markdown body and stopped there, so the preview
still ran lines together — which is exactly what it looked like from the
outside: nothing had changed.
Summary, problem, conclusion, environment and the rest are plain text. They
never pass through the Markdown parser, so their newlines sit in a text node
and HTML collapses them, and the renderer that now emits <br> for the body was
never asked about them.
They render through the same rule now. One helper, one behaviour: a line the
author broke stays broken, wherever they typed it.
DongHyeonka
21f8425f1e