Jump to global mark ring after jumping to register

Question

In buffer B, I press C-x r SPC r to store the position of point.

I switch to buffer A and do some work. I then press C-x r j r to return to the position I saved in buffer B.

How do I get back to the position I left in buffer A? The following do not give the required result: C-x C-x, C-u C-SPC or C-x C-@.

My understanding is that C-x r j r will push the position onto the global mark ring and that C-u C-SPC will take me back there.

Answer 1

That sounds like what you'd expect if "do some work" included, once or more, any of the many actions that set the mark. Each of those actions pushes another mark onto the stack (technically a ring, but stack for our current purposes). Each C-x C-@ pops one off the stack and jumps to it. Try repeating C-x C-@ multiple times. You should see point move to more-or-less recognizable places where you did something other than just typing, one after another.