This function is the means to successfully return a value from the current dialog. Hence, it might be called from an OK button so that pressing the button would cause the dialog to return successfully, whilst the Cancel button would call the counterpart function abort-dialog.
If there is no current dialog then
does nothing and returns
. If there is a current dialog then
either returns non-nil or does a non-local exit. Therefore code that depends on
returning must be written carefully - see the discussion under abort-dialog for details.