MD Volume detection using local loader fails.

[twiggler]

When running acquire on a local target,

I get:

[2024-11-12 14:56:05,544] [DEBUG] local?: Attempting to use loader: <lazyattr dissect.target.loaders.local.LocalLoader loaded=True>
[2024-11-12 14:56:05,603] [WARNING] Failed to detect <class 'dissect.target.volumes.md.MdVolumeSystem'> logical volume
[2024-11-12 14:56:05,603] [DEBUG] 
Traceback (most recent call last):
File "/opt/acquire-api/lib/python3.9/site-packages/dissect/target/volume.py", line 192, in detect_volume
File "/opt/acquire-api/lib/python3.9/site-packages/dissect/target/volumes/md.py", line 43, in _detect_volume
File "/opt/acquire-api/lib/python3.9/site-packages/dissect/volume/md/md.py", line 153, in find_super_block
TypeError: unsupported operand type(s) for //=: 'NoneType' and 'int'

When determining the size, it is not taken into account that the size property might be None:

dissect.volume/dissect/volume/md/md.py

Line 153 in dd3b289

size //= SECTOR_SIZE

Since the BufferedStream is constructed without a size in the local loader: https://github.com/fox-it/dissect.target/blob/a899df6a9ede4394ae3c4efc8f7a5026a8427947/dissect/target/loaders/local.py#L172,

the default value of None is passed to AlignedStream I think.

minimal fix on md.py- fix case of size=none and than do the seek

if (size := getattr(fh, "size", None) is None:  size = fh.seek(0, io.SEEK_END)