Re: [cvs] bug when using pc-selection-mode/transient-mark-mode

[Richard Stallman]

    sit_for(... display = 1)
    wait_reading_process_input()

In the C code there are just two places that deactivate the mark:

    editfns.c:802:  current_buffer->mark_active = tem;
    keyboard.c:1755:              current_buffer->mark_active = Qnil;

Once you are at that point, could you try enabling breakpoints at
those two places and see if they go off?

You can also do this

  (add-hook 'deactivate-mark-hook (lambda () (x-display-color-cells)))

That won't do anything really, but if you put a breakpoint in C
at Fx_display_color_cells, that will stop in the C debugger
when the mark is deactivated.

etc/DEBUG gives adivce on how to get a Lisp backtrace when that
happens.

    [BTW: it's unneccessarily (except for historic reasons) confusing that the
    lisp sit-for and the C sit_for have opposite meanings for their
    arguments.]

I wouldn't say they are opposite.  The C function sit_for has DISPLAY
instead of NODISP--is that what you mean?  But it also has two
additional arguments.  WIth that much difference, they are not
really comparable.  If the only difference were DISPLAY vs NODISP
them it might be good to change the C function.