svn commit: r366472 - head/usr.bin/backlight

[Baptiste Daroussin]

Author: bapt
Date: Tue Oct  6 08:18:09 2020
New Revision: 366472
URL: https://svnweb.freebsd.org/changeset/base/366472

Log:
  backlight: check the lenght if the input before trimming '%'
  
  Reported by:	hps
  Reviewed by:	manu
  Differential Revision:	https://reviews.freebsd.org/D26693

Modified:
  head/usr.bin/backlight/backlight.c

Modified: head/usr.bin/backlight/backlight.c
==============================================================================
--- head/usr.bin/backlight/backlight.c	Tue Oct  6 08:05:19 2020	(r366471)
+++ head/usr.bin/backlight/backlight.c	Tue Oct  6 08:18:09 2020	(r366472)
@@ -145,7 +145,8 @@ main(int argc, char *argv[])
 
 		if (argc == 1) {
 			/* ignore a trailing % for user friendlyness */
-			if (argv[0][strlen(argv[0]) - 1] == '%')
+			if (strlen(argv[0]) > 0 &&
+			    argv[0][strlen(argv[0]) - 1] == '%')
 				argv[0][strlen(argv[0]) - 1] = '\0';
 			percent = strtonum(argv[0], 0, 100, &percent_error);
 			if (percent_error)