Re: [PATCH 2/3] stash: avoid feeding directories to update-index
Hi Elijah,
On Wed, 8 Sep 2021, Elijah Newren via GitGitGadget wrote:
Show 34 quoted lines
> From: Elijah Newren <newren@gmail.com>
>
> When a file is removed from the cache, but there is a file of the same
> name present in the working directory, we would normally treat that file
> in the working directory as untracked. However, in the case of stash,
> doing that would prevent a simple 'git stash push', because the untracked
> file would be in the way of restoring the deleted file.
>
> git stash, however, blindly assumes that whatever is in the working
> directory for a deleted file is wanted and passes that path along to
> update-index. That causes problems when the working directory contains
> a directory with the same name as the deleted file. Add some code for
> this special case that will avoid passing directory names to
> update-index.
>
> Signed-off-by: Elijah Newren <newren@gmail.com>
> ---
> builtin/stash.c | 9 +++++++++
> t/t3903-stash.sh | 2 +-
> 2 files changed, 10 insertions(+), 1 deletion(-)
>
> diff --git a/builtin/stash.c b/builtin/stash.c
> index 8f42360ca91..b85cf9d267e 100644
> --- a/builtin/stash.c
> +++ b/builtin/stash.c
> @@ -313,6 +313,12 @@ static int reset_head(void)
> return run_command(&cp);
> }
>
> +static int is_path_a_directory(const char *path)
> +{
> + struct stat st;
> + return (!lstat(path, &st) && S_ISDIR(st.st_mode));
> +}Git's API is unnecessarily confusing (because grown organically), so it is easy to get confused by that `is_directory()` function that is declared in `cache.h` and defined in `abspath.c`:
/*
* Do not use this for inspecting *tracked* content. When path is a
* symlink to a directory, we do not want to say it is a directory when
* dealing with tracked content in the working tree.
*/
int is_directory(const char *path)
{
struct stat st;
return (!stat(path, &st) && S_ISDIR(st.st_mode));
}The difference I see is that you use an `lstat()`, which is kind of important here.
Maybe you could add a paragraph pointing out that we cannot use `is_directory()` here because it would follow symbolic links, which we need to avoid here?
Show 24 quoted lines
> +
> static void add_diff_to_buf(struct diff_queue_struct *q,
> struct diff_options *options,
> void *data)
> @@ -320,6 +326,9 @@ static void add_diff_to_buf(struct diff_queue_struct *q,
> int i;
>
> for (i = 0; i < q->nr; i++) {
> + if (is_path_a_directory(q->queue[i]->one->path))
> + continue;
> +
> strbuf_addstr(data, q->queue[i]->one->path);
>
> /* NUL-terminate: will be fed to update-index -z */
> diff --git a/t/t3903-stash.sh b/t/t3903-stash.sh
> index 0727a494aa4..fc74918ccc0 100755
> --- a/t/t3903-stash.sh
> +++ b/t/t3903-stash.sh
> @@ -1307,7 +1307,7 @@ test_expect_success 'stash -c stash.useBuiltin=false warning ' '
> test_must_be_empty err
> '
>
> -test_expect_failure 'git stash succeeds despite directory/file change' '
> +test_expect_success 'git stash succeeds despite directory/file change' 'Show 7 quoted lines
> test_create_repo directory_file_switch_v1 &&
> (
> cd directory_file_switch_v1 &&
> --
> gitgitgadget
>
>
Elijah Newren via GitGitGadget
