patch 8.1.1653: ubsan warns for possibly passing NULL pointer commit https://github.com/vim/vim/commit/0d07155c8bbaca1a527b79da358438253a60839f Author: Bram Moolenaar <Bram@vim.org> Date: Mon Jul 8 22:04:03 2019 +0200 patch 8.1.1653: ubsan warns for possibly passing NULL pointer Problem: Ubsan warns for possibly passing NULL pointer. Solution: Skip code when length is zero. (Dominique Pelle, closes https://github.com/vim/vim/issues/4631)

TYPEMAP
VIWIN	T_VIOBJNOMUNGE
VIBUF	T_VIOBJNOMUNGE

INPUT
T_VIOBJNOMUNGE
	if (sv_isa($arg, \"${ntype}\")) {
	    IV tmp = SvIV((SV*)SvRV($arg));
	    $var = INT2PTR($type, tmp);
	    if (!tmp)
		croak(\"$ntype no longer exists\");
	}
	else
	    croak(\"$var is not of type ${ntype}\")