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

h ==<sp>

foo

(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.

Expected behaviour:

Edit summary defaults to /* H */

Actual behaviour:

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&section=1

Version: 1.19
Severity: normal