Proposal: Migrate official jfx repo to GitHub + Skara tooling

[Kevin Rushforth]

To: OpenJFX Contributors,

As most of you are aware, Project Skara is moving forward with a 
proposed JEP [1] to migrate various OpenJDK projects to git, likely 
hosted on GitHub. A read-only git mirror of the HG openjfx/jfx-dev/rt 
repo [2] is available on GitHub at openjdk/jfx [3]. Similarly, there is 
a read-only mirror of the jdk/jdk repo [4] as well.

We've been talking with the Skara team about having OpenJFX be one of 
the "early adopters" in the git transition. Since a large percentage of 
the JavaFX code reviews are already happening on GitHub as pull requests 
against the javafxports/openjdk-jfx (sandbox) mirror, the OpenJFX 
project would be a natural fit for this.

For contributors who are not Committers, there won't be many 
differences, other than some of the steps will go away (e.g., the Skara 
tooling will automate the RFR email). For Committers, there will be some 
minor differences, primarily around eliminating steps -- no more need to 
merge the pull request into "develop", export the patch, import it into 
a Mercurial repo, and push it to the official HG repo. Instead, you will 
use the "/integrate" command as a PR comment to merge the pull request, 
and then you are done. You will still need to update JBS, at least 
initially, to resolve the bug as fixed and add the URL to the commit, 
but even that will be automated at some point.

Developers who are interested in leaning more about the Skara tools and 
workflow can find information on the Skara Wiki [5], GitHub project [6], 
and mailing list [7]. I note that using the Skara client-side tools on 
your desktop is completely optional. I expect many (most?) developers 
will use the GitHub workflow they are already used to via the web 
interface, but there is an option for those who want to use the command 
line tools like "git pr".

As a final note, I recommend waiting to create a personal fork of the 
openjdk/jfx mirror, since the Skara team is going to re-convert all 
openjdk/* mirrors in a couple days [8], and you will just end up having 
to delete and refork.

Comments on this proposal are welcome.

-- Kevin

[1] https://openjdk.java.net/jeps/357
[2] http://hg.openjdk.java.net/openjfx/jfx-dev/rt
[3] https://github.com/openjdk/jfx
[4] https://github.com/openjdk/jdk
[5] https://wiki.openjdk.java.net/display/skara
[6] https://github.com/openjdk/skara
[7] https://mail.openjdk.java.net/mailman/listinfo/skara-dev
[8] 
https://mail.openjdk.java.net/pipermail/skara-dev/2019-August/000327.html