The dos() function needs a new second argument, containing the size

of the partition. Only if the size is 0 should the
special handling of 0 as first argument be triggered.

[This bug caused offset 0 to give C/H/S = 0/0/0 instead of 0/0/1.]

The init_sector0 function needs to decrease the first argument
to the second call to dos() by one to be consistent with the
calls to dos() in change_part().

[This bug caused fdisk -i to create bogus partition tables with
the ending C/H/S value 1 too high.  This usually gives S = 1
instead of S = maximum, so the geometry guessing in the slice
code and perhaps in SCSI BIOSes was defeated.]

Submitted by:	Tor Egge <tegge@itea.ntnu.no>

1 files changed, 13 insertions, 10 deletions

diff --git a/sbin/i386/fdisk/fdisk.c b/sbin/i386/fdisk/fdisk.c
index de26e60..13418c8 100644
--- a/sbin/i386/fdisk/fdisk.c
+++ b/sbin/i386/fdisk/fdisk.c
@@ -183,7 +183,8 @@ static void change_part(int i);
 static void print_params();
 static void change_active(int which);
 static void get_params_to_use();
-static void dos(int sec, unsigned char *c, unsigned char *s, unsigned char *h);
+static void dos(int sec, int size, unsigned char *c, unsigned char *s,
+		unsigned char *h);
 static int open_disk(int u_flag);
 static ssize_t read_disk(off_t sector, void *buf);
 static ssize_t write_disk(off_t sector, void *buf);
@@ -372,8 +373,10 @@ unsigned long size = disksecs - start;
 	partp->dp_start = start;
 	partp->dp_size = size;
 
-	dos(partp->dp_start, &partp->dp_scyl, &partp->dp_ssect, &partp->dp_shd);
-	dos(partp->dp_start+partp->dp_size, &partp->dp_ecyl, &partp->dp_esect, &partp->dp_ehd);
+	dos(partp->dp_start, partp->dp_size, 
+	    &partp->dp_scyl, &partp->dp_ssect, &partp->dp_shd);
+	dos(partp->dp_start + partp->dp_size - 1, partp->dp_size,
+	    &partp->dp_ecyl, &partp->dp_esect, &partp->dp_ehd);
 }
 
 static void
@@ -424,10 +427,10 @@ struct dos_partition *partp = ((struct dos_partition *) &mboot.parts) + i;
 			partp->dp_esect = DOSSECT(tsec,tcyl);
 			partp->dp_ehd = thd;
 		} else {
-			dos(partp->dp_start,
-				&partp->dp_scyl, &partp->dp_ssect, &partp->dp_shd);
-			dos(partp->dp_start+partp->dp_size - 1,
-				&partp->dp_ecyl, &partp->dp_esect, &partp->dp_ehd);
+			dos(partp->dp_start, partp->dp_size,
+			    &partp->dp_scyl, &partp->dp_ssect, &partp->dp_shd);
+			dos(partp->dp_start + partp->dp_size - 1, partp->dp_size,
+			    &partp->dp_ecyl, &partp->dp_esect, &partp->dp_ehd);
 		}
 
 		print_part(i);
@@ -491,14 +494,14 @@ get_params_to_use()
 * Change real numbers into strange dos numbers	*
 \***********************************************/
 static void
-dos(sec, c, s, h)
-int sec;
+dos(sec, size, c, s, h)
+int sec, size;
 unsigned char *c, *s, *h;
 {
 int cy;
 int hd;
 
-	if (sec == 0) {
+	if (sec == 0 && size == 0) {
 		*s = *c = *h = 0;
 		return;
 	}