Using api.php?action=edit&title=Talk:Sandbox§ion=new§iontitle=bar&appendtext=baz&token=(token), where Talk:Sandbox contains the content "foo", results in the content "foo\n==bar==\nfoobaz". The lead content is duplicated in the new section, before the appendtext content.
Version: 1.22.0
Severity: normal
I'm not entirely sure whether specifying appendtext/prependtext with section=new should be an error or if we should DWIM and append/prepend to an empty section.
I'll go with the latter for now, but I could easily be convinced to do the former.
Change 77716 had a related patch set uploaded by Anomie:
API: DWIM for action=edit§ion=new&appendtext=...
Change 77716 merged by jenkins-bot:
API: DWIM for action=edit§ion=new&appendtext=...
The patch is now merged. It should be deployed to WMF wikis with 1.22wmf13, see https://www.mediawiki.org/wiki/MediaWiki_1.22/Roadmap for the schedule.