That is, how can I (from Lisp) create a frame similar to the one that x_create_tip_frame (called by x-show-tip in the C sources) creates when x-gtk-use-system-tooltips is nil?
My original guess was that the relevant part of the C code was this call:
x_default_parameter (f, parms, Qborder_width, make_number (0),
"borderWidth", "BorderWidth", RES_TYPE_NUMBER);
Unfortunately, neither (set-frame-param (selected-frame) 'border-width 0) nor (make-frame '((border-width . 0))) (both inspired from the call above) yield a borderless frame. Still, x-show-tip works fine, so there must be a reliable way :)
Bottom line: How do I create a frame without a border added by the window manager?
