libfdisk: (dos) support partition and MBR overlap

Let's support this crazy use-case in expert menu, because it's normal
for removable FAT disks, etc.

Signed-off-by: Karel Zak <kzak@redhat.com>

diff --git a/libfdisk/src/dos.c b/libfdisk/src/dos.c
index 9cd4ba57cc131616c45c57535db4b6a843a6713d..5d93e09b80ce40b071a5aad6424707fdf9acecc7 100644 (file)
--- a/libfdisk/src/dos.c
+++ b/libfdisk/src/dos.c
@@ -2494,10 +2494,11 @@ int fdisk_dos_move_begin(struct fdisk_context *cxt, size_t i)
                return 0;
        }
 
-       /* the default start is at the second sector of the disk or at the
-        * second sector of the extended partition
+       /* The safe start is at the second sector, but some use-cases require
+        * to have MBR within the first partition , so default to the first
+        * sector of the disk or at the second sector of the extended partition
         */
-       free_start = pe->offset ? pe->offset + 1 : 1;
+       free_start = pe->offset ? pe->offset + 1 : 0;
 
        curr_start = get_abs_partition_start(pe);
 
@@ -2537,6 +2538,11 @@ int fdisk_dos_move_begin(struct fdisk_context *cxt, size_t i)
                dos_partition_set_start(p, new);
 
                partition_set_changed(cxt, i, 1);
+
+               if (new == 0)
+                       fdisk_info(cxt, _("The new beginning of the partition overlaps the disk "
+                                         "label area. Be very careful when using the partition. "
+                                         "You can lose all your partitions on the disk."));
        }
 
        return rc;