The AI export of goods does not work.
It seems to be caused by 20b088. That change stopped the allocation of transports for goods.
I have created a test case and a fix for the issue (I did as the comment in the disabling code change said).
Test: https://sourceforge.net/p/freecol/git/merge-requests/64/
Code: https://sourceforge.net/p/freecol/git/merge-requests/63/
(I did them at SF, should I have made them at GH instead?)
The AI's export of goods do work except for one special case that your test uncovered, that is: A newly built ship in a colony will wait one turn before starting its TransportMission.
Thanks for reporting, I have cherry-picked your commit adding the test :-)
I fixed the issue in a separate commit that also includes some minor stylistic changes to your test.
Please do continue writing tests and code for FreeCol :-)
You can also contact me directly on the Colonization Discord server if you like.
Can confirm it works now.
If you are curious - I am trying to create a function which enables transfer of goods between AI colonies - in the long run, enable the creation of "resource colonies" which supplies a specific resource to other colonies.