Shaoxuan Yuan wrote:
> Originally, <destination> is assumed to be in the working tree. If it is
> not found as a directory, then it is determined to be either a regular file
> path, or error out if used under the second form (move into a directory)
> of 'git-mv'. Such behavior is not ideal, mainly because Git does not
> look into the index for <destination>, which could potentially be a
> SKIP_WORKTREE_DIR, which we need to determine for the later "moving from
> in-cone to out-of-cone" patch.
>
> Change the logic so that Git first check if <destination> is a directory
> with all its contents sparsified (a SKIP_WORKTREE_DIR).
>
> If <destination> is such a sparse directory, then we should modify the
> index the same way as we would if this were a non-sparse directory. We
> must be careful to ensure that the <destination> is marked with
> SKIP_WORKTREE_DIR.
>
> Also add a `dst_w_slash` to reuse the result from `add_slash()`, which
> was everywhere and can be simplified.
This all makes sense. Stepping through the code...
>
> Helped-by: Derrick Stolee <derrickstolee@xxxxxxxxxx>
> Helped-by: Victoria Dye <vdye@xxxxxxxxxx>
> Signed-off-by: Shaoxuan Yuan <shaoxuan.yuan02@xxxxxxxxx>
> ---
> builtin/mv.c | 18 ++++++++++++++----
> 1 file changed, 14 insertions(+), 4 deletions(-)
>
> diff --git a/builtin/mv.c b/builtin/mv.c
> index 0a999640c9..f213a92bf6 100644
> --- a/builtin/mv.c
> +++ b/builtin/mv.c
> @@ -171,6 +171,7 @@ int cmd_mv(int argc, const char **argv, const char *prefix)
> OPT_END(),
> };
> const char **source, **destination, **dest_path, **submodule_gitfile;
> + const char *dst_w_slash;
> enum update_mode *modes;
> struct stat st;
> struct string_list src_for_dst = STRING_LIST_INIT_NODUP;
> @@ -201,6 +202,7 @@ int cmd_mv(int argc, const char **argv, const char *prefix)
> if (argc == 1 && is_directory(argv[0]) && !is_directory(argv[1]))
> flags = 0;
> dest_path = internal_prefix_pathspec(prefix, argv + argc, 1, flags);
> + dst_w_slash = add_slash(dest_path[0]);
...you pre-compute a reusable 'dst_w_slash' here...
> submodule_gitfile = xcalloc(argc, sizeof(char *));
>
> if (dest_path[0][0] == '\0')
> @@ -208,12 +210,20 @@ int cmd_mv(int argc, const char **argv, const char *prefix)
> destination = internal_prefix_pathspec(dest_path[0], argv, argc, DUP_BASENAME);
> else if (!lstat(dest_path[0], &st) &&
> S_ISDIR(st.st_mode)) {
> - dest_path[0] = add_slash(dest_path[0]);
> - destination = internal_prefix_pathspec(dest_path[0], argv, argc, DUP_BASENAME);
> + destination = internal_prefix_pathspec(dst_w_slash, argv, argc, DUP_BASENAME);
...then remove the in-place 'add_slash()' of 'dest_path[0]' and use
'dst_w_slash' in 'internal_prefix_pathspec()'. Makes sense.
> } else {
Then, this block is reached if 'dest_path' is not '.' and it is not a
directory that exists on disk.
Previously, reaching this point meant that 'dest_path' *must* refer to a
file, not a directory. However, you want to add handling for the case where
'dst_w_slash' doesn't exist on disk because all of its contents are sparse:
> - if (argc != 1)
> + if (!path_in_sparse_checkout(dst_w_slash, &the_index) &&
> + empty_dir_has_sparse_contents(dst_w_slash)) {
> + destination = internal_prefix_pathspec(dst_w_slash, argv, argc, DUP_BASENAME);
so the above condition identifies whether 'dest_path[0]' is non-empty in the
index, and sets 'destination' accordingly.
It took me some time to understand what all of these (nested) conditions are
doing; one suggestion I have (feel free to ignore it, since it's really just
a matter of stylistic preference) is reduce some duplicate code/simplify the
change a bit by moving the sparse directory check into the main "if-else"
block:
------------->8------------->8------------->8------------->8------------->8-------------
diff --git a/builtin/mv.c b/builtin/mv.c
index 4729bb1a1a..1c1b9559f6 100644
--- a/builtin/mv.c
+++ b/builtin/mv.c
@@ -203,10 +203,11 @@ int cmd_mv(int argc, const char **argv, const char *prefix)
if (dest_path[0][0] == '\0')
/* special case: "." was normalized to "" */
destination = internal_prefix_pathspec(dest_path[0], argv, argc, DUP_BASENAME);
- else if (!lstat(dest_path[0], &st) &&
- S_ISDIR(st.st_mode)) {
- dest_path[0] = add_slash(dest_path[0]);
- destination = internal_prefix_pathspec(dest_path[0], argv, argc, DUP_BASENAME);
+ else if ((!lstat(dest_path[0], &st) && S_ISDIR(st.st_mode)) ||
+ (!path_in_sparse_checkout(dst_w_slash, &the_index) &&
+ empty_dir_has_sparse_contents(dst_w_slash))) {
+ /* directory dest_path[0] exists on-disk or in the index */
+ destination = internal_prefix_pathspec(dst_w_slash, argv, argc, DUP_BASENAME);
} else {
if (argc != 1)
die(_("destination '%s' is not a directory"), dest_path[0]);
-------------8<-------------8<-------------8<-------------8<-------------8<-------------
It doesn't make for the prettiest condition (so your current approach might
be better in terms of readability) but, to me, it creates a clearer
distinction between the "if" and "else if" blocks (which handle the case
where 'dest_path[0]' is a directory), and the "else" block (which handles
the case where 'dest_path[0]' is a file).
> + } else if (argc != 1) {
> die(_("destination '%s' is not a directory"), dest_path[0]);
> - destination = dest_path;
> + } else {
> + destination = dest_path;
> + }
> + }
> + if (dst_w_slash != dest_path[0]) {
> + free((char *)dst_w_slash);
> + dst_w_slash = NULL;
Looks good.
> }
>
> /* Checking */
