[src/trunk]: src/sbin/fdisk Allow -1 values in the -s <sysid>/<start>/<size> ...

[christos <christos%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/351553565467
branches:  trunk
changeset: 328310:351553565467
user:      christos <christos%NetBSD.org@localhost>
date:      Sun Mar 30 22:18:13 2014 +0000

description:
Allow -1 values in the -s <sysid>/<start>/<size> indicate use the previous
values. For example:
fdisk -f -i /dev/rsd0d # initialize mbr and create an msdos partition.
fdisk -f -u -0 -a -s 169/-1/-1 /dev/rsd0d # converts the msdos partition
to a netbsd one, and makes it active.

diffstat:

 sbin/fdisk/fdisk.c |  23 ++++++++++++++++-------
 1 files changed, 16 insertions(+), 7 deletions(-)

diffs (44 lines):

diff -r a1dae3a7fe2e -r 351553565467 sbin/fdisk/fdisk.c
--- a/sbin/fdisk/fdisk.c        Sun Mar 30 21:52:09 2014 +0000
+++ b/sbin/fdisk/fdisk.c        Sun Mar 30 22:18:13 2014 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: fdisk.c,v 1.146 2014/03/10 15:42:51 jakllsch Exp $ */
+/*     $NetBSD: fdisk.c,v 1.147 2014/03/30 22:18:13 christos Exp $ */
 
 /*
  * Mach Operating System
@@ -39,7 +39,7 @@
 #include <sys/cdefs.h>
 
 #ifndef lint
-__RCSID("$NetBSD: fdisk.c,v 1.146 2014/03/10 15:42:51 jakllsch Exp $");
+__RCSID("$NetBSD: fdisk.c,v 1.147 2014/03/30 22:18:13 christos Exp $");
 #endif /* not lint */
 
 #define MBRPTYPENAMES
@@ -2027,11 +2027,20 @@
                        tmp_bootmenu[0] = 0;
 #endif
 
-       if (!s_flag && partp != NULL) {
-               /* values not specified, default to current ones */
-               sysid = partp->mbrp_type;
-               start = offset + le32toh(partp->mbrp_start);
-               size = le32toh(partp->mbrp_size);
+       if (partp != NULL) {
+               if (!s_flag) {
+                       /* values not specified, default to current ones */
+                       sysid = partp->mbrp_type;
+                       start = offset + le32toh(partp->mbrp_start);
+                       size = le32toh(partp->mbrp_size);
+               } else {
+                       if (sysid == -1)
+                               sysid = partp->mbrp_type;
+                       if (start == (daddr_t)0xffffffff)
+                               start = offset + le32toh(partp->mbrp_start);
+                       if (size == (daddr_t)0xffffffff)
+                               size = le32toh(partp->mbrp_size);
+               }
        }
 
        /* creating a new partition, default to free space */