--- ray/src/common/calfunc.c	2019/07/24 21:20:28	2.24
+++ ray/src/common/calfunc.c	2022/04/08 23:32:25	2.28
@@ -1,5 +1,5 @@
 #ifndef lint
-static const char	RCSid[] = "$Id: calfunc.c,v 2.24 2019/07/24 21:20:28 greg Exp $";
+static const char	RCSid[] = "$Id: calfunc.c,v 2.28 2022/04/08 23:32:25 greg Exp $";
 #endif
 /*
  *  calfunc.c - routines for calcomp using functions.
@@ -150,6 +150,8 @@ funset(				/* set a library function */
 	if (cp == fname) return;
     }
     if ((lp = liblookup(fname)) == NULL) {	/* insert */
+	if (fptr == NULL)
+		return;				/* nothing! */
 	if (libsize >= MAXLIB) {
 	    eputs("Too many library functons!\n");
 	    quit(1);
@@ -356,7 +358,7 @@ libfunc(				/* execute library function */
 	    errno = ERANGE;
     }
 #endif
-    if (errno == EDOM || errno == ERANGE) {
+    if ((errno == EDOM) | (errno == ERANGE)) {
 	wputs(fname);
 	if (errno == EDOM)
 		wputs(": domain error\n");
@@ -394,7 +396,7 @@ l_select(char *nm)	/* return argument #(A1+1) */
 	double	a1 = argument(1);
 	int  n = (int)(a1 + .5);
 
-	if (a1 < -.5 || n >= narg) {
+	if ((a1 < -.5) | (n >= narg)) {
 		errno = EDOM;
 		return(0.0);
 	}
@@ -408,11 +410,10 @@ static double
 l_max(char *nm)		/* general maximum function */
 {
 	int  n = nargum();
-	int  i = 1;
 	double  vmax = argument(1);
 
-	while (i++ < n) {
-		double  v = argument(i);
+	while (n > 1) {
+		double  v = argument(n--);
 		if (vmax < v)
 			vmax = v;
 	}
@@ -424,11 +425,10 @@ static double
 l_min(char *nm)		/* general minimum function */
 {
 	int  n = nargum();
-	int  i = 1;
 	double  vmin = argument(1);
 
-	while (i++ < n) {
-		double  v = argument(i);
+	while (n > 1) {
+		double  v = argument(n--);
 		if (vmin > v)
 			vmin = v;
 	}