bug#4543: window-full-height-p

[martin rudalics]

>>  > Why doesn't it make sense?  The computed value of new_frame_total_cols
>>  > is used to enlarge only the frame's root window:
>>  >
>>  >   if (new_frame_total_cols != FRAME_TOTAL_COLS (f))
>>  >     {
>>  >       set_window_width (FRAME_ROOT_WINDOW (f), new_frame_total_cols, 2);
>>  >
>>  > And for the root window, FRAME_TOTAL_COLS is correct, I think.  The
>>  > window configuration, however complex, does not affect the root
>>  > window, does it?
>>
>> With Emacs -Q I can evaluate
>>
>> (set-window-scroll-bars nil 0 nil)
>>
>> to remove the scroll bar from the *scratch* window keeping the window
>> size unaltered.  When I now evaluate
>>
>> (scroll-bar-mode -1)
>>
>> the width of the frame shrinks and with it the number of columns used
>> for text in the *scratch* window.  This doesn't make sense.
>
> Agreed.  But I must be missing something because I don't see how this
> behavior is related to the code you quoted above.

Indeed.  The above quotation should have started with

>> The problem I see is that the value for new_frame_total_cols
>> calculated by change_frame_size_1 as
>>
>>    /* Compute width of windows in F.
>>       This is the width of the frame without vertical scroll bars.  */
>>    new_frame_total_cols = FRAME_TOTAL_COLS_ARG (f, newwidth);
>>
>>    /* Round up to the smallest acceptable size.  */
>>    check_frame_size (f, &newheight, &newwidth);
>>
>> doesn't make sense for more complex window configurations.

in order to make clear that the assignment to new_frame_total_cols is
reponsible for the behavior I sketched.  Or the fact that setting
`scroll-bar-mode' may trigger frame-resizing in the first place.

martin