Re: [PATCH] t7614: avoid hiding git's exit code in a pipe

[Junio C Hamano <gitster@pobox.com>]

Shlok Kulshreshtha <diy2903@gmail.com> writes:

> The exit code of the upstream command in a pipe is ignored, so in
>
> 	git cat-file commit HEAD | sed -e "1,/^\$/d" >actual
>
> a crash of "git cat-file" would go unnoticed: the exit code of the
> pipeline is that of "sed", which happily succeeds on empty input. The
> test would thus pass even though "git cat-file" failed.
>
> Write the output of "git cat-file" to a file first and run "sed" on
> that file, so that the exit codes of both commands are checked by the
> &&-chain.
>
> Signed-off-by: Shlok Kulshreshtha <diy2903@gmail.com>
> ---
> This is a microproject ("Avoid suppressing git's exit code in test
> scripts"), applying the same fix as c6f44e1da5 (t9813: avoid using
> pipes) to another script. A search of the list did not turn up anyone
> working on t7614; please let me know if it is already taken.

All look trivially correct.

Two clean-up possibilities that are clearly outside the scope of
this patch are

 * There is no need to backslash-quote the dollar sign.
   t7604-merge-custom-message.sh next door uses "1,/^$/d" just fine.

 * This "cat-file the commit object, and strip away the object
   header with sed" pattern appears quite often throughout the test
   suite.

   $ git grep -B1 -e 'sed -e "1,/^\\*$/d"' t/

   shows quite a few hits.  It might make sense to give them an easy
   to use helper script

	commit_body () {
		git cat-file commit "$1" >.commit &&
		sed -e "1,/^$/d" .commit &&
		rm -f .commit
	}

   or something like that.

But again, these are clearly outside the scope of this patch.

>
>  t/t7614-merge-signoff.sh | 9 ++++++---
>  1 file changed, 6 insertions(+), 3 deletions(-)
>
> diff --git a/t/t7614-merge-signoff.sh b/t/t7614-merge-signoff.sh
> index fee258d4f0..e58bf07b7a 100755
> --- a/t/t7614-merge-signoff.sh
> +++ b/t/t7614-merge-signoff.sh
> @@ -45,7 +45,8 @@ test_expect_success 'git merge --signoff adds a sign-off line' '
>  	test_commit main-branch-2 file2 2 &&
>  	git checkout other-branch &&
>  	git merge main --signoff --no-edit &&
> -	git cat-file commit HEAD | sed -e "1,/^\$/d" >actual &&
> +	git cat-file commit HEAD >commit &&
> +	sed -e "1,/^\$/d" commit >actual &&
>  	test_cmp expected-signed actual
>  '
>  
> @@ -55,7 +56,8 @@ test_expect_success 'git merge does not add a sign-off line' '
>  	test_commit main-branch-3 file3 3 &&
>  	git checkout other-branch &&
>  	git merge main --no-edit &&
> -	git cat-file commit HEAD | sed -e "1,/^\$/d" >actual &&
> +	git cat-file commit HEAD >commit &&
> +	sed -e "1,/^\$/d" commit >actual &&
>  	test_cmp expected-unsigned actual
>  '
>  
> @@ -65,7 +67,8 @@ test_expect_success 'git merge --no-signoff flag cancels --signoff flag' '
>  	test_commit main-branch-4 file4 4 &&
>  	git checkout other-branch &&
>  	git merge main --no-edit --signoff --no-signoff &&
> -	git cat-file commit HEAD | sed -e "1,/^\$/d" >actual &&
> +	git cat-file commit HEAD >commit &&
> +	sed -e "1,/^\$/d" commit >actual &&
>  	test_cmp expected-unsigned actual
>  '