--- ray/src/common/tmapcolrs.c	1997/04/18 13:59:46	3.3
+++ ray/src/common/tmapcolrs.c	1998/10/08 16:31:02	3.5
@@ -1,7 +1,7 @@
-/* Copyright (c) 1997 Regents of the University of California */
+/* Copyright (c) 1998 Silicon Graphics, Inc. */
 
 #ifndef lint
-static char SCCSid[] = "$SunId$ LBL";
+static char SCCSid[] = "$SunId$ SGI";
 #endif
 
 /*
@@ -52,7 +52,7 @@ int	len;
 
 	if (tmTop == NULL)
 		returnErr(TM_E_TMINVAL);
-	if (ls == NULL | scan == NULL | len <= 0)
+	if (ls == NULL | scan == NULL | len < 0)
 		returnErr(TM_E_ILLEGAL);
 	if (tmNeedMatrix(tmTop)) {		/* need floating point */
 		register COLOR	*newscan;
@@ -93,22 +93,20 @@ int	len;
 		ls[i] = bi;
 		if (cs == TM_NOCHROM)			/* no color? */
 			continue;
+		if (tmTop->flags & TM_F_BW)
+			cmon[RED] = cmon[GRN] = cmon[BLU] = li;
 							/* mesopic adj. */
 		if (tmTop->flags & TM_F_MESOPIC && bi < BMESUPPER) {
 			register int	pf, sli = normscot(cmon);
 			if (bi < BMESLOWER)
 				cmon[RED] = cmon[GRN] = cmon[BLU] = sli;
 			else {
-				if (tmTop->flags & TM_F_BW)
-					cmon[RED] = cmon[GRN] = cmon[BLU] = li;
 				pf = photofact[bi-BMESLOWER];
 				sli *= 256 - pf;
 				cmon[RED] = ( sli + pf*cmon[RED] ) >> 8;
 				cmon[GRN] = ( sli + pf*cmon[GRN] ) >> 8;
 				cmon[BLU] = ( sli + pf*cmon[BLU] ) >> 8;
 			}
-		} else if (tmTop->flags & TM_F_BW) {
-			cmon[RED] = cmon[GRN] = cmon[BLU] = li;
 		}
 		bi = ( (int4)GAMTSZ*cd->clfb[RED]*cmon[RED]/li ) >> 8;
 		cs[3*i  ] = bi>=GAMTSZ ? 255 : cd->gamb[bi];