@matheusbsbs / matheus-bagliano / commits / 4723ae1007

attr.c: read attributes in a sparse directory

Before this patch, git check-attr was unable to read the attributes from a .gitattributes file within a sparse directory. The original comment was operating under the assumption that users are only interested in files or directories inside the cones. Therefore, in the original code, in the case of a cone-mode sparse-checkout, we didn't load the .gitattributes file. However, this behavior can lead to missing attributes for files inside sparse directories, causing inconsistencies in file handling. To resolve this, revise 'git check-attr' to allow attribute reading for files in sparse directories from the corresponding .gitattributes files: 1.Utilize path_in_cone_mode_sparse_checkout() and index_name_pos_sparse to check if a path falls within a sparse directory. 2.If path is inside a sparse directory, employ the value of index_name_pos_sparse() to find the sparse directory containing path and path relative to sparse directory. Proceed to read attributes from the tree OID of the sparse directory using read_attr_from_blob(). 3.If path is not inside a sparse directory，ensure that attributes are fetched from the index blob with read_blob_data_from_index(). Change the test 'check-attr with pathspec outside sparse definition' to 'test_expect_success' to reflect that the attributes inside a sparse directory can now be read. Ensure that the sparse index case works correctly for git check-attr to illustrate the successful handling of attributes within sparse directories. Helped-by: Victoria Dye <vdye@github.com> Signed-off-by: Shuqi Liang <cheskaqiqi@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>

Shuqi Liang committed Aug 11, 2023 at 10:22 UTC 4723ae1007f94cbb391c4fb5a042adccd038d9ae

2 files changed +48 -19

attr.c

+39 -18

@@ -808,35 +808,56 @@ static struct attr_stack *read_attr_from_blob(struct index_state *istate,

808 static struct attr_stack *read_attr_from_index(struct index_state *istate,

809 const char *path, unsigned flags)

810 {

811 + struct attr_stack *stack = NULL;

812 char *buf;

813 unsigned long size;

814 + int sparse_dir_pos = -1;

815

816 if (!istate)

817 return NULL;

818

819 /*

818 - * The .gitattributes file only applies to files within its

819 - * parent directory. In the case of cone-mode sparse-checkout,

820 - * the .gitattributes file is sparse if and only if all paths

821 - * within that directory are also sparse. Thus, don't load the

822 - * .gitattributes file since it will not matter.

823 - *

824 - * In the case of a sparse index, it is critical that we don't go

825 - * looking for a .gitattributes file, as doing so would cause the

826 - * index to expand.

820 + * When handling sparse-checkouts, .gitattributes files

821 + * may reside within a sparse directory. We distinguish

822 + * whether a path exists directly in the index or not by

823 + * evaluating if 'pos' is negative.

824 + * If 'pos' is negative, the path is not directly present

825 + * in the index and is likely within a sparse directory.

826 + * For paths not in the index, The absolute value of 'pos'

827 + * minus 1 gives us the position where the path would be

828 + * inserted in lexicographic order within the index.

829 + * We then subtract another 1 from this value

830 + * (sparse_dir_pos = -pos - 2) to find the position of the

831 + * last index entry which is lexicographically smaller than

832 + * the path. This would be the sparse directory containing

833 + * the path. By identifying the sparse directory containing

834 + * the path, we can correctly read the attributes specified

835 + * in the .gitattributes file from the tree object of the

836 + * sparse directory.

837 */

828 - if (!path_in_cone_mode_sparse_checkout(path, istate))

829 - return NULL;

838 + if (!path_in_cone_mode_sparse_checkout(path, istate)) {

839 + int pos = index_name_pos_sparse(istate, path, strlen(path));

840

831 - buf = read_blob_data_from_index(istate, path, &size);

832 - if (!buf)

833 - return NULL;

834 - if (size >= ATTR_MAX_FILE_SIZE) {

835 - warning(_("ignoring overly large gitattributes blob '%s'"), path);

836 - return NULL;

841 + if (pos < 0)

842 + sparse_dir_pos = -pos - 2;

843 }

844

839 - return read_attr_from_buf(buf, path, flags);

845 + if (sparse_dir_pos >= 0 &&

846 + S_ISSPARSEDIR(istate->cache[sparse_dir_pos]->ce_mode) &&

847 + !strncmp(istate->cache[sparse_dir_pos]->name, path, ce_namelen(istate->cache[sparse_dir_pos]))) {

848 + const char *relative_path = path + ce_namelen(istate->cache[sparse_dir_pos]);

849 + stack = read_attr_from_blob(istate, &istate->cache[sparse_dir_pos]->oid, relative_path, flags);

850 + } else {

851 + buf = read_blob_data_from_index(istate, path, &size);

852 + if (!buf)

853 + return NULL;

854 + if (size >= ATTR_MAX_FILE_SIZE) {

855 + warning(_("ignoring overly large gitattributes blob '%s'"), path);

856 + return NULL;

857 + }

858 + stack = read_attr_from_buf(buf, path, flags);

859 + }

860 + return stack;

861 }

862

863 static struct attr_stack *read_attr(struct index_state *istate,

t/t1092-sparse-checkout-compatibility.sh

+9 -1

@@ -2271,7 +2271,7 @@ test_expect_success 'check-attr with pathspec inside sparse definition' '

2271 test_all_match git check-attr -a --cached -- deep/a

2272 '

2273

2274 -test_expect_failure 'check-attr with pathspec outside sparse definition' '

2274 +test_expect_success 'check-attr with pathspec outside sparse definition' '

2275 init_repos &&

2276

2277 echo "a -crlf myAttr" >>.gitattributes &&

@@ -2288,6 +2288,14 @@ test_expect_failure 'check-attr with pathspec outside sparse definition' '

2288 test_all_match git check-attr -a --cached -- folder1/a

2289 '

2290

2291 +# NEEDSWORK: The 'diff --check' test is left as 'test_expect_failure' due

2292 +# to an underlying issue in oneway_diff() within diff-lib.c.

2293 +# 'do_oneway_diff()' is not called as expected for paths that could match

2294 +# inside of a sparse directory. Specifically, the 'ce_path_match()' function

2295 +# fails to recognize files inside a sparse directory (e.g., when 'folder1/'

2296 +# is a sparse directory, 'folder1/a' cannot be recognized). The goal is to

2297 +# proceed with 'do_oneway_diff()' if the pathspec could match inside of a

2298 +# sparse directory.

2299 test_expect_failure 'diff --check with pathspec outside sparse definition' '

2300 init_repos &&

2301