--- ray/src/common/mesh.c	2012/11/06 01:56:37	2.25
+++ ray/src/common/mesh.c	2017/03/01 21:51:38	2.28
@@ -1,5 +1,5 @@
 #ifndef lint
-static const char RCSid[] = "$Id: mesh.c,v 2.25 2012/11/06 01:56:37 greg Exp $";
+static const char RCSid[] = "$Id: mesh.c,v 2.28 2017/03/01 21:51:38 greg Exp $";
 #endif
 /*
  * Mesh support routines
@@ -52,6 +52,7 @@ static int
 cvcmp(const char *vv1, const char *vv2)		/* compare encoded vertices */
 {
 	const MCVERT	*v1 = (const MCVERT *)vv1, *v2 = (const MCVERT *)vv2;
+
 	if (v1->fl != v2->fl)
 		return(1);
 	if (v1->xyz[0] != v2->xyz[0])
@@ -99,7 +100,7 @@ getmesh(				/* get new mesh data reference */
 	}
 	if ((pathname = getpath(mname, getrlibpath(), R_OK)) == NULL) {
 		sprintf(errmsg, "cannot find mesh file \"%s\"", mname);
-		error(USER, errmsg);
+		error(SYSTEM, errmsg);
 	}
 	flags &= ~ms->ldflags;
 	if (flags)
@@ -148,41 +149,27 @@ nextmeshtri(				/* get next triangle ID */
 	MESH *mp
 )
 {
-	int		advance = 1;
 	int		pn;
 	MESHPATCH	*pp;
 
-	if (*tip == OVOID) {			/* check for first index */
-		*tip = 0;
-		advance = 0;
-	}
-	pn = *tip >> 10;
+	pn = ++(*tip) >> 10;			/* next triangle (OVOID init) */
 	while (pn < mp->npatches) {
 		pp = &mp->patch[pn];
 		if (!(*tip & 0x200)) {		/* local triangle? */
-			if ((*tip & 0x1ff) < pp->ntris - advance) {
-				*tip += advance;
+			if ((*tip & 0x1ff) < pp->ntris)
 				return(1);
-			}
 			*tip &= ~0x1ff;		/* move on to single-joiners */
 			*tip |= 0x200;
-			advance = 0;
 		}
 		if (!(*tip & 0x100)) {		/* single joiner? */
-			if ((*tip & 0xff) < pp->nj1tris - advance) {
-				*tip += advance;
+			if ((*tip & 0xff) < pp->nj1tris)
 				return(1);
-			}
 			*tip &= ~0xff;		/* move on to double-joiners */
 			*tip |= 0x100;
-			advance = 0;
 		}
-		if ((*tip & 0xff) < pp->nj2tris - advance) {
-			*tip += advance;
+		if ((*tip & 0xff) < pp->nj2tris)
 			return(1);
-		}
 		*tip = ++pn << 10;		/* first in next patch */
-		advance = 0;
 	}
 	return(0);				/* out of patches */
 }
@@ -341,12 +328,12 @@ getmeshtri(			/* get triangle vertices */
 
 int32
 addmeshvert(			/* find/add a mesh vertex */
-	MESH	*mp,
+	MESH		*mp,
 	MESHVERT	*vp
 )
 {
-	LUENT		*lvp;
-	MCVERT		cv;
+	LUENT	*lvp;
+	MCVERT	cv;
 	int	i;
 
 	if (!(vp->fl & MT_V))
@@ -453,8 +440,8 @@ addmeshtri(			/* add a new mesh triangle */
 	OBJECT		mo
 )
 {
-	int32			vid[3], t;
-	int			pn[3], i;
+	int32		vid[3], t;
+	int		pn[3], i;
 	MESHPATCH	*pp;
 
 	if (!(tv[0].fl & tv[1].fl & tv[2].fl & MT_V))
@@ -473,7 +460,7 @@ addmeshtri(			/* add a new mesh triangle */
 			error(INTERNAL, "modifier range error in addmeshtri");
 	}
 				/* assign triangle */
-	if (pn[0] == pn[1] && pn[1] == pn[2]) {	/* local case */
+	if ((pn[0] == pn[1]) & (pn[1] == pn[2])) {	/* local case */
 		pp = &mp->patch[pn[0]];
 		if (pp->tri == NULL) {
 			pp->tri = (struct PTri *)malloc(
@@ -499,8 +486,7 @@ addmeshtri(			/* add a new mesh triangle */
 				pp->trimat[pp->ntris] = mo;
 			return(pn[0] << 10 | pp->ntris++);
 		}
-	}
-	if (pn[0] == pn[1]) {
+	} else if (pn[0] == pn[1]) {
 		t = vid[2]; vid[2] = vid[1]; vid[1] = vid[0]; vid[0] = t;
 		i = pn[2]; pn[2] = pn[1]; pn[1] = pn[0]; pn[0] = i;
 	} else if (pn[0] == pn[2]) {
@@ -549,7 +535,7 @@ checkmesh(MESH *mp)			/* validate mesh data */
 {
 	static char	embuf[128];
 	int		nouvbounds = 1;
-	int	i;
+	int		i;
 					/* basic checks */
 	if (mp == NULL)
 		return("NULL mesh pointer");