commit https://github.com/vim/vim/commit/cf619daa8e0ef9a335f27f65eb74e422a17d4f92 Author: Bram Moolenaar <Bram@vim.org> Date: Tue Sep 1 20:53:24 2015 +0200 patch 7.4.853 Problem: "zt" in diff mode does not always work properly. (Gary Johnson) Solution: Don't count filler lines twice. (Christian Brabandt)

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}\")