Since no one did answer I guess the answer of what the intension is, is simply: minecraft can't be changed this way.
Since this got closed as "Works as intended" can somebody please explain me why this works as intended and what the intension is here?
Alex, my (and not only my) stations are broken, yes, because I expected this to work and it does not. Basically you speak against all behavioural changes. If that is the policy for minecraft, then things like the Redstone update should never happen as well.
Alex, if you argument like that, then pressing a button from the configuration in step2.jpg, should not lead to a configuration as shown in step3.jpg/step4.jpg but instead directly to the configuration shown in step5.jpg. And then I would expect that pressing a button would change step5 into step2. I would still not expect step5 to be a "final" configuration. Coming from that direction, that it doesn't care whether the other piece stays connected or not, seems to be wrong to me. I can understand implementation wise why it is like this now, but that doesn't make it right 😉
The problem with corner rail is then to define how they switch. An isolated (nowhere connected) corner rail has in theory two ways to switch, thus should not. If we don't use connected, but possibly connected and that simply as "there is another rail" and don't care about the orientation of that rail, then I could define the following rules: A rail with 0, 2 or 4 possible connections cannot switch. A corner rail with one possible connection can switch the unconnected side. A corner rail with 3 possible connections can switch the opposite directions, meaning east-west or north-south. Please note: I define here only the way a corner rail can switch, not how a rail becomes a corner rail
These rules are local enough for the implementation, since it has no cascading effects. The cases with 0,2 and 4 possible connections are today also not switchable, thus it does not disable anything that could switch before. And they allow my double T-Junction to work.
I strongly assume that the switching rules are as they are because of the event of placing a rails, in other words: from how to make them a corner rail. And I think those should be different rule sets.
If that is how they are intended to work, then you can surely explain what the reason for this behaviour is. For me I see I can flip directions with a button normally. But here it stops working once a certain configuration is reached. So what is the reason for being able to switch the rails into a fixed position, that is no escaping from?
added smalelr images
As the original author of this issue I just wanted to say hello. It is 10 years now, I still play Minecraft. I am not complaining, I see no need to rush to fix this.