In the hypothetical, Samsung intentionally put it under GPL. It is truly and legitimately licensed GPL, they're just not giving it to the public at this moment.
Something doesn't truly become GPL until it is distributed, because the license is a contract between licensor and licensee. Only someone with copyright permission can distribute code. Samsung didn't grant copyright permission to its employees, nor did it distribute GPL code to its employees. (In the hypothetical.)
So if I write a piece of software, burn it onto a hundred disks, put the disks in a nicely labeled basket for people to take, go to lunch, and people grab some, at what point does the license kick in?
I find strange your statement that there is no license despite every file header (hypothetically) claiming a license, and this being authorized by the entire management chain.
In the example with you putting the disks in a basket, you've intentionally made them available for people that are not your employees to take, so you're distributing them. The license kicks in when one is taken. It's analogous to downloading software.
The point is that for a license to be binding it has to be offered willingly. If I sign a blank check and you steal it from me, filling out $1000 and your name, although you'll be able to cash it, you have no right to the money, and I can undo the action.
The reason internal code is special is because the employees are not considered individuals to whom the company has distributed the software. Instead they are a part of the company.
I identified some relevant questions in the GPL FAQ. I believe that the first one and third one are what you care about.
I just find it very strange that you can't apply a license-for-distribution without actually distributing. That means if I want to make sure a piece of software is GPL, and nobody can take that away in the future, I have to perform an action such as uploading to github or burning a single CD and giving it to a homeless person. And somehow giving away that first single copy is what makes the GPL kick in for all other copies in the world.
That's still not quite correct. A license is a contract. It requires two parties. Every time somebody gives GPL software to somebody else, the contract is entered into and the license is granted. Giving away the first copy only establishes a license between you and the first recipient. That recipient in turn grants a license to whoever he gives it to, if and when he chooses to do so. In particular, I cannot demand that the first recipient give me a copy of the source code unless I have been granted license to the software by him.
If you want to be really sure a piece of software is GPL, it would probably be alright to include a file in your source tree on your harddrive saying that whoever finds it is free to make a copy of the project for themselves and consider that you have distributed it to them. It's about the clear intent to distribute.
> Giving away the first copy only establishes a license between you and the first recipient. That recipient in turn grants a license to whoever he gives it to, if and when he chooses to do so.
That's a logical way of looking at it, but it disagrees with the GPL FAQ. Note especially "If the version has been released elsewhere, then the thief probably does have the right to make copies and redistribute them under the GPL".
Plus, you can have a unilateral contract that's open to anyone willing to accept the terms. You don't have to take any action per person to 'establish' it.
The thief "probably" has the right to make copies because the diff between what he stole and what is readily available elsewhere for free is nil, and he can go and grab a copy with almost zero effort. But if A gives a copy only to B (it has still been "released elsewhere"), B keeps his copy to himself, and the thief steals a copy from A, the thief does not have any rights simply because B has a copy. That would be absurd! The FSF lawyers use the word "probably" because they believe this is what the court would find if a thief distributed something like an unmodified version of Linux taken off of a stolen hard drive.
However I was wrong about contracts vs. licenses. Obviously I am not a lawyer.
I don't know how I can make it clearer.