Subject: Re: [PATCH v3 0/4] breaking changes: switch default initial branch name to "main"

From: Phillip Wood <[email-masked]>
Date: Wed, 17 Sep 2025 15:53:34 +0100

On 17/09/2025 10:22, Junio C Hamano wrote:
> Junio C Hamano <[email-masked]> writes:
> 
> We do this without telling them how to permanently configure the
> default name of the initial branch, and that design choice is very
> much deliberate.

That makes sense
> It also needs to be noted thta the advise token to squelch the
> message is the same advice.defaultBranchName as before, which is
> also very much deliberate.  The users who do have that configured
> are those who _have_ been using Git since before 3.0, and they are
> not the target audience for the new advice message.  Reusing the
> same advise token ensures that they do not have to turn the message
> off.

That's good

Thanks for following up on this. The code changes look good modulo
the typo pointed out by Kristoffer. I've left a few thoughts on the
test changes below.

> diff --git c/t/t0000-basic.sh w/t/t0000-basic.sh
> index 2b63e1c86c..54ed80ebd4 100755
> --- c/t/t0000-basic.sh
> +++ w/t/t0000-basic.sh
> @@ -220,7 +220,8 @@ test_expect_success 'subtest: --verbose option' '
>   	test_done
>   	EOF
>   	mv t1234-verbose/err t1234-verbose/err+ &&
> -	grep -v "^Initialized empty" t1234-verbose/err+ >t1234-verbose/err &&
> +	grep -v -e "^Initialized empty" -e "^hint:" t1234-verbose/err+ \
> +		>t1234-verbose/err &&
>   	check_sub_test_lib_test_err t1234-verbose \
>   		<<-\EOF_OUT 3<<-\EOF_ERR
>   	> ok 1 - passing test
> diff --git c/t/t0001-init.sh w/t/t0001-init.sh
> index df0040b9ac..5fe7b8c674 100755
> --- c/t/t0001-init.sh
> +++ w/t/t0001-init.sh
> @@ -562,9 +562,9 @@ test_expect_success 'init warns about invalid init.defaultObjectFormat' '
>   	test_when_finished "rm -rf repo" &&
>   	test_config_global init.defaultObjectFormat garbage &&
>   
> -	echo "warning: unknown hash algorithm ${SQ}garbage${SQ}" >expect &&
> +	expect="warning: unknown hash algorithm ${SQ}garbage${SQ}" &&
>   	git init repo 2>err &&
> -	test_cmp expect err &&
> +	test_grep "$expect" err &&
>   
>   	git -C repo rev-parse --show-object-format >actual &&
>   	echo $GIT_DEFAULT_HASH >expected &&
> @@ -649,9 +649,9 @@ test_expect_success 'init warns about invalid init.defaultRefFormat' '
>   	test_when_finished "rm -rf repo" &&
>   	test_config_global init.defaultRefFormat garbage &&
>   
> -	echo "warning: unknown ref storage format ${SQ}garbage${SQ}" >expect &&
> +	expect="warning: unknown ref storage format ${SQ}garbage${SQ}" &&
>   	git init repo 2>err &&
> -	test_cmp expect err &&
> +	test_grep "$expect" err &&

The test changes up to this point strike me as somewhat unfortunate as
these tests are perfectly content with the existing advice. I assume
this stems from us not setting GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
anymore when WITH_BREAKING_CHANGES is enabled. I think we should do
something like

diff --git b/t/test-lib.sh b/t/test-lib.sh
--- a/t/test-lib.sh
+++ b/t/test-lib.sh
@@ -127,13 +127,15 @@ then
  	export GIT_TEST_DISALLOW_ABBREVIATED_OPTIONS
  fi
  
+# Explicitly set the default branch name for testing, to avoid the
+# transitory "git init" warning under --verbose.
  if test -z "$WITH_BREAKING_CHANGES"
  then
-	# Explicitly set the default branch name for testing, to avoid the
-	# transitory "git init" warning under --verbose.
  	: ${GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME:=master}
-	export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
+else
+	: ${GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME:=main}
  fi
+export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
  
  ################################################################
  # It appears that people try to run tests without building...

To address that which will also stop the advice appearing when the
tests are run with --verbose as well.

>   	git -C repo rev-parse --show-ref-format >actual &&
>   	echo $GIT_DEFAULT_REF_FORMAT >expected &&
> @@ -868,18 +868,18 @@ test_expect_success 'overridden default initial branch name (config)' '
>   	grep nmb actual
>   '
>   
> -test_expect_success !WITH_BREAKING_CHANGES 'advice on unconfigured init.defaultBranch' '
> +test_expect_success 'advice on unconfigured init.defaultBranch' '
>   	GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME= git -c color.advice=always \
>   		init unconfigured-default-branch-name 2>err &&
>   	test_decode_color <err >decoded &&
>   	test_grep "<YELLOW>hint: " decoded
>   '
>   
> -test_expect_success 'advice on unconfigured init.defaultBranch disabled' '
> +test_expect_success 'advice on unconfigured init.defaultBranch can be disabled' '
>   	test_when_finished "rm -rf no-advice" &&
>   
>   	GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME= \
> -		git -c advice.defaultBranchName=false init no-advice 2>err &&
> +	git -c advice.defaultBranchName=false init no-advice 2>err &&

The indentation is changed here but not above. I'd be happy to leave
this alone, but if we're going to remove the indentation here shouldn't
we do the same above?

>   	test_grep ! "hint: " err

Do we want to check the advice that is printed now that we have two
different messages?

Thanks

Phillip