bug#46299: 28.0.50; Value of tab-bar-show not respected in new frames.

[martin rudalics]

> +  "Determine the value of tab-bar-lines for FRAME.
> +The returned value will either be 1 or 0, meaning whether to show
> +the tab-bar or not. If tab-bar-mode is off, the returned value is
> +0. Otherwise the result depends on the value of the customizable
> +variable `tab-bar-show'."

Please use active voice and always make sure to leave two spaces in
front of a new sentence.  I would write it as

(defun tab-bar--tab-bar-lines-for-frame (frame)
  "Return new value of `tab-bar-lines' parameter for specified FRAME.
Return 0 if `tab-bar-mode' is not enabled on FRAME or ....
Return 1 if `tab-bar-mode' is enabled on FRAME and the variable
`tab-bar-show' ...

Call this function when ..."

where the last sentence would describe when and why this function should
be called, justifying the "new" in the doc-string.  Instead of "new" you
can also use "adjusted" if the value gets just adjusted or your earlier
"correct" provided an earlier calculation was "incorrect".

martin