> >> I don't understand the above call to `make-terminal-frame': does it
> >> create a new frame, or just a new tab?  If the first, then I don't
> >> understand how it works, and if the second, it's wrong because adding
> >> a tab should have nothing to do with frame creation.
> > The fact that make-tab calls directly make-terminal-frame is just a
> legacy
> > of the old code, when a tab used to be just a frame.
>
> So it will need to change.  But does `make-tab' create a new tab or
> a tabbar?  If a tab, then I don't understand any more why the init-code
> is needed.
>

I did not insert :initcode inside the tab, because I should have written
more C code. I should add the :initcode after the (make-terminal-frame '(tab
. t)), or I should have written code to commute temporarly to a tab without
activating it.

This is why I executed the :initcode before calling (make-terminal-frame....
)

In my case the :initcode should be

  ;; save curent win config
  (setq sym (make-symbol "winconfig"))
  (set sym  (current-window-configuration))


My actual C code does not allow me to insert :initcode as parameter to
(make-terminal-frame (tab . t)), and this is why I created make-tab and
separated the :initcode.

I come into a vicious circle if I pass :initcode to make-terminal frame, and
I did not want to write more C code before to clarify with other emacs
developers how tabs should look like.