Function: window-valid-p
window-valid-p is a function defined in window.c.
Signature
(window-valid-p OBJECT)
Documentation
Return t if OBJECT is a valid window and nil otherwise.
A valid window is either a window that displays a buffer or an internal window. Windows that have been deleted are not valid.
Probably introduced at or before Emacs version 24.1.
Source Code
// Defined in /usr/src/emacs/src/window.c
{
return WINDOW_VALID_P (object) ? Qt : Qnil;
}