The PullRequest reflex is now an acquired behaviour.
I started a discussion at https://markmail.org/message/jx426hxxwvllynx3, summary:
Our workflow is to contribute patches through Jira. We need to clearly document how the project is going to work with Pull Requests. as part of https://cwiki.apache.org/confluence/display/OFBIZ/OFBiz+Contributors+Best+Practices
Remark Jacques: But I know that it will not be enough. So I'll also add a notice in the top of our main README.adoc to make it clear on our main Github page.