In Idfb870e3e85537ad682ae1ca6400168955634d4c (https://gerrit.wikimedia.org/r/c/mediawiki/services/parsoid/+/634672) we relaxed section start boundaries *inside templates* but not *at top level*.
But many pages consist of trancluded sections, and the [edit section] links viewed by the reader "just work" in that case, jumping directly to a "section edit" interface on the transcluded article. But now there's a disagreement about whether certain content is included in that section or not. On the page with the transclusions, the comments (and other rendering-transparent content) were included in the section, but when we jump to the page which was transcluded to actually edit the section, we are suddenly at top-level and that content is not considered part of the section any more.
See https://en.wikipedia.org/wiki/User:Cscott/Parsoid_section_test for some examples.
This can be resolved one of two ways:
- Don't included render-transparent content in the section (but this create spurious conflicts between template boundaries and section boundaries; see T265737)
- Include render-transparent content in the section *at top-level too* (not just inside transclusions) so that the definition of the section boundaries is consistent when we switch between views.