Re: [PATCH] apply: reload .gitattributes after patching it

> When applying multiple patches with git am, or when rebasing using the
> am backend, it's possible that one of our patches has updated a
> gitattributes file. Currently, we cache this information, so if a
> file in a subsequent patch has attributes applied, the file will be
> written out with the attributes in place as of the time we started the
> rebase or am operation, not with the attributes applied by the previous
> patch. This problem does not occur when using the -m or -i flags to
> rebase.

> Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
> ---
>  apply.c           | 11 +++++++++++
>  convert.c         |  9 ++++++++-
>  convert.h         |  6 ++++++
>  t/t3400-rebase.sh | 23 +++++++++++++++++++++++
>  4 files changed, 48 insertions(+), 1 deletion(-)
>
> diff --git a/apply.c b/apply.c
> index cde95369bb..b959b88b8e 100644
> --- a/apply.c
> +++ b/apply.c
> @@ -4643,6 +4643,7 @@ static int apply_patch(struct apply_state *state,
>  	struct patch *list = NULL, **listp = &list;
>  	int skipped_patch = 0;
>  	int res = 0;
> +	int flush_attributes = 0;
>
>  	state->patch_input_file = filename;
>  	if (read_patch_file(&buf, fd) < 0)
> @@ -4670,6 +4671,14 @@ static int apply_patch(struct apply_state *state,
>  			patch_stats(state, patch);
>  			*listp = patch;
>  			listp = &patch->next;
> +
> +			if (!flush_attributes && patch->new_name) {
> +				char *dummy = strip_path_suffix(patch->new_name, GITATTRIBUTES_FILE);

> +				/* The patch applied to a .gitattributes file. */
> +				if (dummy)
> +					flush_attributes = 1;
> +				free(dummy);
> +			}
>  		}
>  		else {
>  			if (state->apply_verbosity > verbosity_normal)
> @@ -4746,6 +4755,8 @@ static int apply_patch(struct apply_state *state,
>  	if (state->summary && state->apply_verbosity > verbosity_silent)
>  		summary_patch_list(list);
>
> +	if (flush_attributes)
> +		reset_parsed_attributes();
>  end:
>  	free_patch_list(list);
>  	strbuf_release(&buf);
> diff --git a/convert.c b/convert.c
> index 94ff837649..030e9b81b9 100644
> --- a/convert.c
> +++ b/convert.c
> @@ -1293,10 +1293,11 @@ struct conv_attrs {
>  	const char *working_tree_encoding; /* Supported encoding or default encoding if NULL */
>  };
>
> +static struct attr_check *check;
> +
>  static void convert_attrs(const struct index_state *istate,
>  			  struct conv_attrs *ca, const char *path)
>  {
> -	static struct attr_check *check;
>  	struct attr_check_item *ccheck = NULL;
>
>  	if (!check) {
> @@ -1339,6 +1340,12 @@ static void convert_attrs(const struct index_state *istate,
>  		ca->crlf_action = CRLF_AUTO_INPUT;
>  }
>
> +void reset_parsed_attributes(void)
> +{
> +	attr_check_free(check);
> +	check = NULL;
> +}
> +

>  int would_convert_to_git_filter_fd(const struct index_state *istate, const char *path)
>  {
>  	struct conv_attrs ca;
> diff --git a/convert.h b/convert.h
> index 831559f10d..3710969d43 100644
> --- a/convert.h
> +++ b/convert.h
> @@ -94,6 +94,12 @@ void convert_to_git_filter_fd(const struct index_state *istate,
>  int would_convert_to_git_filter_fd(const struct index_state *istate,
>  				   const char *path);
>
> +/*
> + * Reset the internal list of attributes used by convert_to_git and
> + * convert_to_working_tree.
> + */
> +void reset_parsed_attributes(void);
> +
>  /*****************************************************************
>   *
>   * Streaming conversion support
> diff --git a/t/t3400-rebase.sh b/t/t3400-rebase.sh
> index 80b23fd326..062dc41df7 100755
> --- a/t/t3400-rebase.sh
> +++ b/t/t3400-rebase.sh
> @@ -301,6 +301,29 @@ test_expect_success 'rebase --am and --show-current-patch' '
>  	)
>  '
>
> +test_expect_success 'rebase --am and .gitattributes' '
> +	test_create_repo attributes &&
> +	(
> +		cd attributes &&
> +		test_commit init &&
> +		test_config filter.test.clean "sed -e '\''s/smudged/clean/g'\''" &&
> +		test_config filter.test.smudge "sed -e '\''s/clean/smudged/g'\''" &&
> +
> +		test_commit second &&
> +		git checkout -b test HEAD^ &&
> +
> +		echo "*.txt filter=test" >.gitattributes &&
> +		git add .gitattributes &&
> +		test_commit third &&
> +
> +		echo "This text is smudged." >a.txt &&
> +		git add a.txt &&
> +		test_commit fourth &&
> +		git rebase master &&
> +		grep "smudged" a.txt
> +	)
> +'
> +