Re: [PATCH 4/5] pack-write: pass hash_algo to `write_rev_file()`

> From: Karthik Nayak <karthik.188@gmail.com>
> 
> The `write_rev_file()` function uses the global `the_hash_algo` variable
> to access the repository's hash function. To avoid global variable
> usage, let's pass the hash function from the layers above.
> 
> Altough the layers above could have access to the hash function
> internally, simply pass in `the_hash_algo`. This avoids any
> compatibility issues and bubbles up global variable usage to upper
> layers which can be eventually resolved.
> 
> However, in `midx-write.c`, since all usage of global variables is
> removed, don't reintroduce them and instead use the `repo` available in
> the context.