Re: [PATCH 04/17] chunk-format.h: extract oid_version()

> There are three definitions of an identical function which converts
> `the_hash_algo` into either 1 (for SHA-1) or 2 (for SHA-256). There is a
> copy of this function for writing both the commit-graph and
> multi-pack-index file, and another inline definition used to write the
> .rev header.
> 
> Consolidate these into a single definition in chunk-format.h. It's not
> clear that this is the best header to define this function in, but it
> should do for now.

> (Worth noting, the .rev caller expects a 4-byte unsigned, but the other
> two callers work with a single unsigned byte. The consolidated version
> uses the latter type, and lets the compiler widen it when required).
> 
> Another caller will be added in a subsequent patch.

>  chunk-format.c | 12 ++++++++++++
>  chunk-format.h |  3 +++
>  commit-graph.c | 18 +++---------------
>  midx.c         | 18 +++---------------
>  pack-write.c   | 15 ++-------------