On Sun, Feb 25, 2018 at 10:29:29AM +0700, Duy Nguyen wrote:
> When I set unknown hash algo here, I think some test failed
> mysteriously because it used rawsz field (which has value zero), it
> didn't match some expectation, the code went to the error handling
> path, which eventually failed with some error message, but it's not
> obvious that the problem was rawsz being zero and back tracking that
> took me some time.
> 
> With NULL hash_algo, any dereferencing fails immediately with a nice
> stack trace. Another reason to push me towards NULL hash algo is, even
> if we prefer nice messages over segmentation faults, we can't avoid it
> completely anyway (empty_tree and empty_blob are still NULL in unknown
> hash algo and will cause segfaults). Might as well make things
> consistent and always segfault.

That makes sense.  Thanks for the explanation.
-- 
brian m. carlson / brian with sandals: Houston, Texas, US
https://www.crustytoothpaste.net/~bmc | My opinion only
OpenPGP: https://keybase.io/bk2204