From: Junio C Hamano <gitster@pobox.com>
Date: Wed, 29 Apr 2020 19:24:48 GMT
Subject: Re: [PATCH 4/4] lib-submodule-update: pass OVERWRITING_FAIL
Message-ID: <xmqqpnbqw0vz.fsf@gitster.c.googlers.com>
In-Reply-To: <22eacd20a8213c3281974a6c103fd2d00c95efaa.1588162842.git.liu.denton@gmail.com>

Denton Liu <liu.denton@gmail.com> writes:

> We are using `test_must_fail $command`. However, $command is not
> necessarily a git command; it could be a test helper function.
>
> In an effort to stop using test_must_fail with non-git commands, instead
> of invoking `test_must_fail $command`, run
> `OVERWRITING_FAIL=test_must_fail $command` instead. Increase the
> granularity of the test helper functions by specifically choosing the
> individual git invocation which is designed to fail.

Sorry, but I do not know why this is a good idea.

>  test_submodule_switch_common () {
> +	OVERWRITING_FAIL=
>  	command="$1"
>  	######################### Appearing submodule #########################
>  	# Switching to a commit letting a submodule appear creates empty dir ...
> @@ -443,7 +446,7 @@ test_submodule_switch_common () {
>  		(
>  			cd submodule_update &&
>  			git branch -t replace_sub1_with_directory origin/replace_sub1_with_directory &&
> -			test_must_fail $command replace_sub1_with_directory &&
> +			OVERWRITING_FAIL=test_must_fail $command replace_sub1_with_directory &&

Here, $command may or may not be a git command and more importantly,
it could be a shell function, right?  Then we need to take it into
account that 

	VAR=VAL shell_function args...

will not work, no?

Some shells do not make this a single-shot environment variable
assignment that will not persist once the single function invocation
returns.