--- ray/src/rt/m_clip.c	2003/02/25 02:47:22	2.6
+++ ray/src/rt/m_clip.c	2007/07/25 04:12:36	2.10
@@ -1,5 +1,5 @@
 #ifndef lint
-static const char	RCSid[] = "$Id: m_clip.c,v 2.6 2003/02/25 02:47:22 greg Exp $";
+static const char	RCSid[] = "$Id: m_clip.c,v 2.10 2007/07/25 04:12:36 greg Exp $";
 #endif
 /*
  *  m_clip.c - routine for clipped (cut) objects.
@@ -8,6 +8,7 @@ static const char	RCSid[] = "$Id: m_clip.c,v 2.6 2003/
 #include "copyright.h"
 
 #include  "ray.h"
+#include  "rtotypes.h"
 
 /*
  *  Clipping objects permit holes and sections to be taken out
@@ -18,10 +19,11 @@ static const char	RCSid[] = "$Id: m_clip.c,v 2.6 2003/
  */
 
 
-int
-m_clip(m, r)			/* clip objects from ray */
-register OBJREC  *m;
-register RAY  *r;
+extern int
+m_clip(			/* clip objects from ray */
+	register OBJREC  *m,
+	register RAY  *r
+)
 {
 	OBJECT  cset[MAXSET+1], *modset;
 	OBJECT  obj, mod;
@@ -53,6 +55,8 @@ register RAY  *r;
 		}
 		m->os = (char *)modset;
 	}
+	if (r == NULL)
+		return(0);			/* just initializing */
 	if (r->clipset != NULL)
 		setcopy(cset, r->clipset);
 	else
@@ -76,15 +80,16 @@ register RAY  *r;
 	r->newcset = cset;
 	if (strcmp(m->oargs.sarg[0], VOIDID)) {
 		int  inside = 0;
-		register RAY  *rp;
+		register const RAY  *rp;
 					/* check for penetration */
 		for (rp = r; rp->parent != NULL; rp = rp->parent)
 			if (!(rp->rtype & RAYREFL) && rp->parent->ro != NULL
-					&& inset(modset, rp->parent->ro->omod))
+					&& inset(modset, rp->parent->ro->omod)) {
 				if (rp->parent->rod > 0.0)
 					inside++;
 				else
 					inside--;
+			}
 		if (inside > 0) {	/* we just hit the object */
 			flipsurface(r);
 			return(rayshade(r, lastmod(obj, m->oargs.sarg[0])));