Subject: Re: [PATCH v4] diff: add config option relative

From: Đoàn Trần Công Danh <[email-masked]>
Date: Sun, 17 May 2020 09:14:52 +0700

Hi Laurent,

On 2020-05-16 21:40:33+0200, Laurent Arnoud <[email-masked]> wrote:
> Subject: Re: [PATCH v4] diff: add config option relative

I think the subject should be changed to.

	diff: allow overriding --relative

> The `diff.relative` boolean option set to `true` show only changes on
> the current directory and show relative pathnames to the current
> directory.
> 
> Teach --no-relative to override earlier --relative
> 
> Signed-off-by: Laurent Arnoud <[email-masked]>
> ---
>  Documentation/config/diff.txt   |  4 ++
>  Documentation/diff-options.txt  |  3 ++
>  diff.c                          | 16 ++++--
>  t/t9904-diff-relative-config.sh | 93 +++++++++++++++++++++++++++++++++

I think t99?? is used for miscellaneous tests.

To me, diff-relative things should be tested in t4045-diff-relative.sh

>  4 files changed, 113 insertions(+), 3 deletions(-)
>  create mode 100755 t/t9904-diff-relative-config.sh
> 
> diff --git a/Documentation/config/diff.txt b/Documentation/config/diff.txt
> index ff09f1cf73..76537c3b0c 100644
> --- a/Documentation/config/diff.txt
> +++ b/Documentation/config/diff.txt
> @@ -105,6 +105,10 @@ diff.mnemonicPrefix::
>  diff.noprefix::
>  	If set, 'git diff' does not show any source or destination prefix.
> 
> +diff.relative::
> +	If set to "true", 'git diff' does not show changes outside of the directory

I think it's better to change "true" to either:
'true' (generated to <em>true</em>, or
`true` generated to <code>true<code>

Not sure which one is prefered, though.
This file uses both 2 styles.

I _think_ `true` is preferred.

> +	and show pathnames relative to the current directory.
> +
>  diff.orderFile::
>  	File indicating how to order files within a diff.
>  	See the '-O' option to linkgit:git-diff[1] for details.
> diff --git a/Documentation/diff-options.txt b/Documentation/diff-options.txt
> index bb31f0c42b..1b279904eb 100644
> --- a/Documentation/diff-options.txt
> +++ b/Documentation/diff-options.txt
> @@ -651,6 +651,9 @@ ifndef::git-format-patch[]
>  	not in a subdirectory (e.g. in a bare repository), you
>  	can name which subdirectory to make the output relative
>  	to by giving a <path> as an argument.
> +--no-relative::

Please merge this option with `--relative[=<path>]` above.
And says something likes:

	`--no-relative` can be used to countermand
	both `diff.relative` and previous `--relative`

> @@ -5195,8 +5202,11 @@ static int diff_opt_relative(const struct option *opt,
>  {
>  	struct diff_options *options = opt->value;
> 
> -	BUG_ON_OPT_NEG(unset);
> -	options->flags.relative_name = 1;
> +	if (unset) {
> +		options->flags.relative_name = 0;
> +	} else {
> +		options->flags.relative_name = 1;
> +	}

Can this block be simplified as:

	options->flags.relative_name = !unset;

> +check_diff_relative () {
> +	dir=$1
> +	shift
> +	expect=$1
> +	shift
> +	relative_opt=$1
> +	shift
> +	short_blob=$(git rev-parse --short "$(git hash-object subdir/file2)")

I think current practice want to have git hash-object as separated.
And all git-related code moved inside test_expect*

diff --git a/t/t9904-diff-relative-config.sh b/t/t9904-diff-relative-config.sh
index 23ab1af5e0..4747647917 100755
--- a/t/t9904-diff-relative-config.sh
+++ b/t/t9904-diff-relative-config.sh
@@ -20,17 +20,18 @@ check_diff_relative () {
 	shift
 	relative_opt=$1
 	shift
-	short_blob=$(git rev-parse --short "$(git hash-object subdir/file2)")
-	cat >expected <<-EOF
-	diff --git a/$expect b/$expect
-	new file mode 100644
-	index 0000000..$short_blob
-	--- /dev/null
-	+++ b/$expect
-	@@ -0,0 +1 @@
-	+other content
-	EOF
-	test_expect_success "config.relative $relative_opt -p $*" "
+	test_expect_success "config.relative $relative_opt -p $* in $dir" "
+		hash=\$(git hash-object subdir/file2) &&
+		short_blob=\$(git rev-parse --short \$hash) &&
+		cat >expected <<-EOF &&
+		diff --git a/$expect b/$expect
+		new file mode 100644
+		index 0000000..\$short_blob
+		--- /dev/null
+		+++ b/$expect
+		@@ -0,0 +1 @@
+		+other content
+		EOF
 		test_config -C $dir diff.relative $relative_opt &&
 		git -C '$dir' diff -p $* HEAD^ >actual &&
 		test_cmp expected actual

> +	short_blob_file1=$(git rev-parse --short "$(git hash-object file1)")
> +	short_blob_file2=$(git rev-parse --short "$(git hash-object subdir/file2)")
> +	cat >expected <<-EOF
> +	diff --git a/file1 b/file1
> +	new file mode 100644
> +	index 0000000..$short_blob_file1
> +	--- /dev/null
> +	+++ b/file1
> +	@@ -0,0 +1 @@
> +	+content
> +	diff --git a/$expect b/$expect
> +	new file mode 100644
> +	index 0000000..$short_blob_file2
> +	--- /dev/null
> +	+++ b/$expect
> +	@@ -0,0 +1 @@
> +	+other content
> +	EOF
> +	cat expected

Above comment also applied here.
And remove this debug cat.

-- 
Danh