--- ray/src/hd/rhcopy.c	2017/05/03 18:05:15	3.28
+++ ray/src/hd/rhcopy.c	2018/08/02 18:33:42	3.30
@@ -1,5 +1,5 @@
 #ifndef lint
-static const char	RCSid[] = "$Id: rhcopy.c,v 3.28 2017/05/03 18:05:15 greg Exp $";
+static const char	RCSid[] = "$Id: rhcopy.c,v 3.30 2018/08/02 18:33:42 greg Exp $";
 #endif
 /*
  * Copy data into a holodeck file
@@ -101,7 +101,7 @@ holheadline(		/* check holodeck header line */
 	void	*vhf
 )
 {
-	char	fmt[32];
+	char	fmt[MAXFMTLEN];
 	int	*hf = vhf;
 
 	if (formatval(fmt, s)) {
@@ -398,6 +398,8 @@ addpicz(		/* add a picture + depth-buffer */
 			error(USER, errmsg);
 		}
 		for (i = scanlen(&prs); i--; ) {	/* do each pixel */
+			if (zscn[i] <= 0.0)
+				continue;		/* illegal depth */
 			pix2loc(vl, &prs, i, j);
 			aftd = viewray(ro, rd, &phd.vw, vl[0], vl[1]);
 			if (aftd < -FTINY)