Subject: Re: [PATCH v2 3/4] run-command: move envvar-resetting function

From: Junio C Hamano <[email-masked]>
Date: Tue, 08 Jun 2021 13:14:31 +0900

Jonathan Tan <[email-masked]> writes:

> There is a function that resets environment variables, used when
> invoking a sub-process in a submodule. The lazy-fetching code (used in
> partial clones) will need this function in a subsequent commit, so move
> it to a more central location.
>
> Signed-off-by: Jonathan Tan <[email-masked]>
> ---
>  run-command.c | 10 ++++++++++
>  run-command.h |  9 +++++++++
>  submodule.c   | 14 ++------------
>  3 files changed, 21 insertions(+), 12 deletions(-)
>
> diff --git a/run-command.c b/run-command.c
> index be6bc128cd..a6c458119c 100644
> --- a/run-command.c
> +++ b/run-command.c
> @@ -1892,3 +1892,13 @@ int run_auto_maintenance(int quiet)
>  
>  	return run_command(&maint);
>  }
> +
> +void prepare_other_repo_env(struct strvec *env_array)
> +{
> +	const char * const *var;
> +
> +	for (var = local_repo_env; *var; var++) {
> +		if (strcmp(*var, CONFIG_DATA_ENVIRONMENT))
> +			strvec_push(env_array, *var);
> +	}
> +}

It does make sense to move this to run-command.c from submodule.c
and the function name is already suitable for being global.  I
however cannot help wondering if we should also pay attention to the
GIT_CONFIG_KEY_$n and GIT_CONFIG_VALUE_$n pairs (which is not a new
problem in this patch).

This helper may sit better next to prep_childenv(), instead of just
saying "the location does not matter, just append randomly at the
end", though.

Otherwise looking good.

Thanks.

> diff --git a/run-command.h b/run-command.h
> index d08414a92e..a1d9107f5b 100644
> --- a/run-command.h
> +++ b/run-command.h
> @@ -483,4 +483,13 @@ int run_processes_parallel_tr2(int n, get_next_task_fn, start_failure_fn,
>  			       task_finished_fn, void *pp_cb,
>  			       const char *tr2_category, const char *tr2_label);
>  
> +/**
> + * Convenience function which adds all GIT_* environment variables to env_array
> + * with the exception of GIT_CONFIG_PARAMETERS. When used as the env_array of a
> + * subprocess, these entries cause the corresponding environment variables to
> + * be unset in the subprocess. See local_repo_env in cache.h for more
> + * information.
> + */
> +void prepare_other_repo_env(struct strvec *env_array);
> +
>  #endif
> diff --git a/submodule.c b/submodule.c
> index 0b1d9c1dde..a30216db52 100644
> --- a/submodule.c
> +++ b/submodule.c
> @@ -484,26 +484,16 @@ static void print_submodule_diff_summary(struct repository *r, struct rev_info *
>  	strbuf_release(&sb);
>  }
>  
> -static void prepare_submodule_repo_env_no_git_dir(struct strvec *out)
> -{
> -	const char * const *var;
> -
> -	for (var = local_repo_env; *var; var++) {
> -		if (strcmp(*var, CONFIG_DATA_ENVIRONMENT))
> -			strvec_push(out, *var);
> -	}
> -}
> -
>  void prepare_submodule_repo_env(struct strvec *out)
>  {
> -	prepare_submodule_repo_env_no_git_dir(out);
> +	prepare_other_repo_env(out);
>  	strvec_pushf(out, "%s=%s", GIT_DIR_ENVIRONMENT,
>  		     DEFAULT_GIT_DIR_ENVIRONMENT);
>  }
>  
>  static void prepare_submodule_repo_env_in_gitdir(struct strvec *out)
>  {
> -	prepare_submodule_repo_env_no_git_dir(out);
> +	prepare_other_repo_env(out);
>  	strvec_pushf(out, "%s=.", GIT_DIR_ENVIRONMENT);
>  }