Change the order of checks to ensure that we have at least one comment
before we try comparing ranges, to avoid issues with empty headings
having collapsed ranges. It should be a tiny bit faster this way, too.
Bug: T304377
Change-Id: I59ad30cfc075dcec882e048d2d199744efec2114
Previously, we required a signature at the end of the comment.
This was a pretty rough heuristic that did not correctly handle
many comments that we would consider entirely properly signed
in CommentParser (e.g. comments wrapped in formatting like
<small>…</small>, comments with a post-scriptum or in parentheses,
or comments generated by various templates).
Now we process the user input using the same code that adds reply
links, and only add a signature when we detect that there really
isn't a signature (including template-generated), or if the signature
is in the wrong place and would result in the reply link showing up
in the wrong place as well (not at the end of the comment).
Bug: T278442
Bug: T268558
Bug: T278355
Bug: T291421
Bug: T282983
Change-Id: I46b6110af328ebdf93b7dfc2bd941e04391a1599
