$NetBSD: patch-aa,v 1.3 2020/08/24 06:30:58 tnn Exp $

Check that the proper arguments are given.

--- modeline_vfr.c.orig	2020-08-24 06:27:34.226844393 +0000
+++ modeline_vfr.c
@@ -6,7 +6,7 @@
 *
 * Use on your own risk.
 *
-* Input:  Resolution and  Vertical Frequence
+* Input:  Resolution and  Vertical Frequency
 * Output: Modeline
 *
 * Example use:
@@ -44,6 +44,12 @@ main( int argc, char** argv )
 	float	step =10.0;
 	float 	s_rr;
 
+	if (argc != 4) {
+		(void) fprintf(stderr, "Usage: %s <horizontal resolution> <vertical resolution> <vertical freq in Hertz>\n", *argv);
+		(void) fprintf(stderr, "e.g. %s 640 480 75\n", *argv);
+		exit(1);
+	}
+
         sscanf(argv[1],"%f",&hr);
         sscanf(argv[2],"%f",&vr);
         sscanf(argv[3],"%f",&s_rr);
@@ -88,7 +94,7 @@ do{
 	printf("  Vertical Resolution:     %4.0f \n",vr);
 	printf("  Vertical Refresh Rate:   %4.2f Hz \n",rr);
 	printf("  Horizontal Refresh Rate: %4.2f KHz \n",hsf);
-	printf("  Dot Clock Frequence:     %4.2f MHz \n",dcf);
+	printf("  Dot Clock Frequency:     %4.2f MHz \n",dcf);
 	printf("\n");
 	printf(" # V-freq: %4.2f Hz  // h-freq: %4.2f KHz\n Modeline \"%dx%d\" %4.2f  %4d %4d %4d %4d  %4d %4d %4d %4d \n",rr,hsf,(int)(hr),(int)(vr),(dcf),(int)(hr),(int)(hfront),(int)(hsync),(int)(hfl),(int)(vr),(int)(vfront),(int)(vsync),(int)(vfl));