For a == header == heading. If there's a trailing space after the closing ==, then the header is not properly included in default edit summary for section edits
Steps to reproduce:
Create a page with the following
(Replacing the <sp> with a space. So there should be 1 trailing space after the closing ==. The foo on the next line is to prevent parser from stripping that space).
Edit section 1.
Edit summary defaults to /* H */
Edit summary defaults to being empty.
I checked, and this issue was not present on 1.18.
Originally reported by PiZero on irc for the url https://en.wikinews.org/w/index.php?title=Wikinews_interviews_Americans_Elect_presidential_candidate_Mike_Ballantine&action=edit§ion=1