Merge branch 'sb/describe-blob'

"git describe $garbage" stopped giving any errors when the garbage happens to be a string with 40 hexadecimal letters. * sb/describe-blob: describe: confirm that blobs actually exist

Junio C Hamano committed Feb 27, 2018 at 10:33 UTC 1ba6846a19b0358ddf4098d44ba5804646c36412

No changes.