Hiring your own people to branch and maintain the software for your own purposes is not "distribution". If you're a company relying on software you don't own, and you need it to do something different, you can hire coders to maintain it in your direction. That's totally different from reselling it.

When the people you are hiring are an external contractor, that probably counts as distribution though.

It only counts as distribution if you give it to them and they start using the software as well.

If you send them the software, they reverse engineer it and fix bugs that's not distribution.

If you send it to them, they fix bugs and then start using it themselves that is distribution.

No, I don't think so. If the company has the right to edit the code, then it can contract that out. If someone paid the company to clone or use the code, that would be distribution.

From the FSF's GPL FAQ:

However, when the organization transfers copies to other organizations or individuals, that is distribution. In particular, providing copies to contractors for use off-site is distribution.

https://www.gnu.org/licenses/gpl-faq.html#InternalDistributi...

For use off-site. Hiring a programmer off-site to maintain it isn't "use". Giving it to someone to use in a productive way in furtherance of your business or in exchange for money would be "use".

Distribution matters because it triggers legal consequences--you need a license to distribute. The FSF can't rewrite the law. So they can't say "doing X is distribution" and then claim that doing X requires a license.

So whether the FSF calls something distribution in their own FAQ is irrelevant, unless the FSF is your lawyer and giving you legal advice.

Quite. Being allowed to fix the OS yourself, but not share the result, is like being allowed to fix your car yourself, but being forbidden to set up business as a mechanic-for-hire.

I used to be able to fix a Morris Minor; but I wouldn't dream of trying to fix anything but the bodywork on a modern car.

You made me wonder if sharing a patcher that modifies the program files would be legal under the EU law.

IANAL but sharing the patcher probably wouldn't be. Sharing the code it patched, or a patched version of that code, would be piracy.

Sorry, what farmer has the ability to repair a design problem in an engine? In reality the vast majority of fixes are just temporary patches using materials that quickly degrade and need to be constantly replaced.

More than you think. Farmers often know how to weld, etc.