cannot operate ++ for void pointer

diff --git a/src/header.c b/src/header.c
index 5b710b9..33fb52e 100644 (file)
--- a/src/header.c
+++ b/src/header.c
@@ -61,8 +61,9 @@ calc_sum(p, len)
     int len;
 {
     int sum = 0;
     int len;
 {
     int sum = 0;

+    unsigned char *pc = (unsigned char*)p;

 
 

-    while (len--) sum += *(unsigned char*)p++;
+    while (len--) sum += *pc++;

 
     return sum & 0xff;
 }
 
     return sum & 0xff;
 }