On Tue, Apr 30, 2024 at 11:47:24AM +1000, James Liu wrote:
[snip]
> diff --git a/environment.h b/environment.h
> index 05fd94d7be..26e87843e1 100644
> --- a/environment.h
> +++ b/environment.h
> @@ -57,6 +57,13 @@ const char *getenv_safe(struct strvec *argv, const char *name);
>  #define GIT_TEXT_DOMAIN_DIR_ENVIRONMENT "GIT_TEXTDOMAINDIR"
>  #define GIT_ATTR_SOURCE_ENVIRONMENT "GIT_ATTR_SOURCE"
>  
> +/*
> + * Environment variable used to propagate the --no-advice global option to the
> + * advice_enabled() helper, even when run in a subprocess.
> + * This is an internal variable that should not be set by the user.
> + */
> +#define GIT_ADVICE "GIT_ADVICE"

Almost all of the other defines in this file have an "_ENVIRONMENT"
suffix. We should probably do the same here to mark it as the name of
the environment variable, which otherwise wouldn't be obvious.

>  /*
>   * Environment variable used in handshaking the wire protocol.
>   * Contains a colon ':' separated list of keys with optional values
> diff --git a/git.c b/git.c
> index 654d615a18..6283d126e5 100644
> --- a/git.c
> +++ b/git.c
> @@ -38,7 +38,7 @@ const char git_usage_string[] =
>  	   "           [--exec-path[=<path>]] [--html-path] [--man-path] [--info-path]\n"
>  	   "           [-p | --paginate | -P | --no-pager] [--no-replace-objects] [--bare]\n"
>  	   "           [--git-dir=<path>] [--work-tree=<path>] [--namespace=<name>]\n"
> -	   "           [--config-env=<name>=<envvar>] <command> [<args>]");
> +	   "           [--config-env=<name>=<envvar>] [--no-advice] <command> [<args>]");
>  
>  const char git_more_info_string[] =
>  	N_("'git help -a' and 'git help -g' list available subcommands and some\n"
> @@ -337,6 +337,10 @@ static int handle_options(const char ***argv, int *argc, int *envchanged)
>  			setenv(GIT_ATTR_SOURCE_ENVIRONMENT, cmd, 1);
>  			if (envchanged)
>  				*envchanged = 1;
> +		} else if (!strcmp(cmd, "--no-advice")) {
> +			setenv(GIT_ADVICE, "0", 1);
> +			if (envchanged)
> +				*envchanged = 1;
>  		} else {
>  			fprintf(stderr, _("unknown option: %s\n"), cmd);
>  			usage(git_usage_string);
> diff --git a/t/t0018-advice.sh b/t/t0018-advice.sh
> index 0dcfb760a2..2ce2d4668a 100755
> --- a/t/t0018-advice.sh
> +++ b/t/t0018-advice.sh
> @@ -29,4 +29,24 @@ test_expect_success 'advice should not be printed when config variable is set to
>  	test_must_be_empty actual
>  '
>  
> +test_expect_success 'advice should not be printed when --no-advice is used' '
> +	cat << EOF > expect &&

We typically write those `cat >expect <<-EOF`. I assume you cannot use
the dash here because the "README" string is indented by a tab. But the
order of redirects should still be reversed.

> +On branch master
> +
> +No commits yet
> +
> +Untracked files:
> +	README
> +
> +nothing added to commit but untracked files present
> +EOF
> +
> +	git init advice-test &&
> +  test_when_finished "rm -fr advice-test" &&

Let's run `test_when_finished` before creating the repo.

> +  cd advice-test &&
> +  touch README &&
> +  git --no-advice status > ../actual &&
> +  test_cmp ../expect ../actual

Nit: these should be indented by tabs, not spaces.

> +'

We could add two more tests that explicitly set the environment
variable, once to `true` and once to `false`. This would at least
somewhat represent the case of running Git subcommands, even though we
cannot test whether Git actually knows to set the envvar like this.

Patrick

>  test_done
> -- 
> 2.44.0
> 
>