Re: [PATCH] diff-tree: read the index so attribute checks work in bare repositories

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

Brandon Williams <bmwill@google.com> writes:

> A regression was introduced in 557a5998d (submodule: remove
> gitmodules_config, 2017-08-03) to how attribute processing was handled
> in bare repositories when running the diff-tree command.
>
> By default the attribute system will first try to read ".gitattribute"
> files from the working tree and then falls back to reading them from the
> index if there isn't a copy checked out in the worktree.  Prior to
> 557a5998d the index was read as a side effect of the call to
> 'gitmodules_config()' which ensured that the index was already populated
> before entering the attribute subsystem.
>
> Since the call to 'gitmodules_config()' was removed the index is no
> longer being read so when the attribute system tries to read from the
> in-memory index it doesn't find any ".gitattribute" entries effectively
> ignoring any configured attributes.
>
> Fix this by explicitly reading the index during the setup of diff-tree.

Thanks, both.  Will queue.




> Reported-by: Ben Boeckel <ben.boeckel@kitware.com>
> Signed-off-by: Brandon Williams <bmwill@google.com>
> ---
>
> This patch should fix the regression.  Let me know if it doesn't solve the
> issue and I'll investigate some more.
>
>  builtin/diff-tree.c        |  1 +
>  t/t4015-diff-whitespace.sh | 17 +++++++++++++++++
>  2 files changed, 18 insertions(+)
>
> diff --git a/builtin/diff-tree.c b/builtin/diff-tree.c
> index d66499909..cfe7d0281 100644
> --- a/builtin/diff-tree.c
> +++ b/builtin/diff-tree.c
> @@ -110,6 +110,7 @@ int cmd_diff_tree(int argc, const char **argv, const char *prefix)
>  
>  	git_config(git_diff_basic_config, NULL); /* no "diff" UI options */
>  	init_revisions(opt, prefix);
> +	read_cache();
>  	opt->abbrev = 0;
>  	opt->diff = 1;
>  	opt->disable_stdin = 1;
> diff --git a/t/t4015-diff-whitespace.sh b/t/t4015-diff-whitespace.sh
> index 559a7541a..6e061a002 100755
> --- a/t/t4015-diff-whitespace.sh
> +++ b/t/t4015-diff-whitespace.sh
> @@ -636,6 +636,23 @@ test_expect_success 'check with space before tab in indent (diff-tree)' '
>  	test_must_fail git diff-tree --check HEAD^ HEAD
>  '
>  
> +test_expect_success 'check with ignored trailing whitespace attr (diff-tree)' '
> +	test_when_finished "git reset --hard HEAD^" &&
> +
> +	# Create a whitespace error that should be ignored.
> +	echo "* -whitespace" > ".gitattributes" &&
> +	git add ".gitattributes" &&
> +	echo "trailing space -> " > "trailing-space" &&
> +	git add "trailing-space" &&
> +	git commit -m "trailing space" &&
> +
> +	# With a worktree diff-tree ignores the whitespace error
> +	git diff-tree --root --check HEAD &&
> +
> +	# Without a worktree diff-tree still ignores the whitespace error
> +	git -C .git diff-tree --root --check HEAD
> +'
> +
>  test_expect_success 'check trailing whitespace (trailing-space: off)' '
>  	git config core.whitespace "-trailing-space" &&
>  	echo "foo ();   " >x &&