--- ray/src/gen/genprism.c	1989/02/02 11:16:28	1.1
+++ ray/src/gen/genprism.c	1996/02/22 14:38:51	2.5
@@ -10,16 +10,20 @@ static char SCCSid[] = "$SunId$ LBL";
  *		command line or from a file.  Their order together
  *		with the extrude direction will determine surface
  *		orientation.
- *
- *     8/24/87
  */
 
 #include  <stdio.h>
 
+#include  <math.h>
+
 #include  <ctype.h>
 
 #define  MAXVERT	1024		/* maximum # vertices */
 
+#ifdef  DCL_ATOF
+extern double  atof();
+#endif
+
 char  *pmtype;		/* material type */
 char  *pname;		/* name */
 
@@ -36,7 +40,6 @@ main(argc, argv)
 int  argc;
 char  **argv;
 {
-	double  atof();
 	int  an;
 	
 	if (argc < 4)
@@ -50,6 +53,11 @@ char  **argv;
 		an = 4;
 	} else if (isdigit(argv[3][0])) {
 		nverts = atoi(argv[3]);
+		if (nverts > MAXVERT) {
+			fprintf(stderr, "%s: too many vertices (%d limit)\n",
+					argv[0], MAXVERT);
+			exit(1);
+		}
 		if (argc-3 < 2*nverts)
 			goto userr;
 		for (an = 0; an < nverts; an++) {
@@ -102,18 +110,23 @@ userr:
 
 
 readverts(fname)		/* read vertices from a file */
-FILE  *fname;
+char  *fname;
 {
 	FILE  *fp;
 
-	if (fname == NULL)
+	if (fname == NULL) {
 		fp = stdin;
-	else if ((fp = fopen(fname, "r")) == NULL) {
+		fname = "<stdin>";
+	} else if ((fp = fopen(fname, "r")) == NULL) {
 		fprintf(stderr, "%s: cannot open\n", fname);
 		exit(1);
 	}
 	while (fscanf(fp, "%lf %lf", &vert[nverts][0], &vert[nverts][1]) == 2)
-		nverts++;
+		if (++nverts >= MAXVERT) {
+			fprintf(stderr, "%s: too many vertices (%d limit)\n",
+					fname, MAXVERT-1);
+			exit(1);
+		}
 	fclose(fp);
 }