SHA1 is a hash. That alone does not make it 'crypto'. It's just a hash.
It happens to be a hash with fairly good collision resistance. Maybe not the best we have for modern crypto purposes, but that's not what it's being used for. It's being used to check and record unique tags for patches (as far as I know, my git knowledge is far from complete).
Cryptography does concern itself with data integrity but the reverse does not have to be true if you're not talking about part of a system you care about mitigating attacks on.
That's my take anyway.
--Edit-- for completeness I should add that SHA1 by itself is absolutely not a MAC
It happens to be a hash with fairly good collision resistance. Maybe not the best we have for modern crypto purposes, but that's not what it's being used for. It's being used to check and record unique tags for patches (as far as I know, my git knowledge is far from complete).
Cryptography does concern itself with data integrity but the reverse does not have to be true if you're not talking about part of a system you care about mitigating attacks on.
That's my take anyway.
--Edit-- for completeness I should add that SHA1 by itself is absolutely not a MAC