On 26/06/30 01:47PM, Patrick Steinhardt wrote:

It is possible to configure an arbitrary "shallow" file via two
mechanisms, and the respective logic to handle these is split across two
locations:

  - Via the "GIT_SHALLOW_FILE" environment variable, which is handled in
    `setup_git_env_internal()`.

  - Via the global "--shallow-file=" command line option, which is
    handled in `handle_options()`.

Ok.

We can rather easily unify this logic by not configuring the shallow
file in `handle_options()`, but instead overwriting the environment
variable. The environment variable itself is then handled inside of
`apply_repository_format()`, which is responsible for configuring a
discovered Git directory.

What is supposed to be the correct order for processing shallow file
configuration here? Does this mean that the `--shallow-file` option now
overwrites the environment variable? Was this how it already was?

This new logic is similar in nature to how we handle the other global
options already, all of which end up setting an environment variable.
So for one this gives us more consistency. But more importantly, this
change means that `the_repository` will not contain any relevant state
anymore before we hit `apply_repository_format()` once we're at the end
of this patch series. Consequently, it will become possible for us to
completely discard `the_repository` and populate it anew.

I can't say that I'm a fan of using environment variables to store
global state in this manner, but I guess if there is precdent and this
is making us more consistent, it is probably fine. I guess the other
option would be to store the read configuration is some intermediate
structure to be applied later, but that may not be worth it here.

-Justin