unpack-trees: fix sparse directory recursion check

Ensure 'is_sparse_directory_entry()' receives a valid 'name_entry *' if one
exists in the list of tree(s) being unpacked in 'unpack_callback()'.

Currently, 'is_sparse_directory_entry()' is called with the first
'name_entry' in the 'names' list of entries on 'unpack_callback()'. However,
this entry may be empty even when other elements of 'names' are not (such as
when switching from an orphan branch back to a "normal" branch). As a
result, 'is_sparse_directory_entry()' could incorrectly indicate that a
sparse directory is *not* actually sparse because the name of the index
entry does not match the (empty) 'name_entry' path.

Fix the issue by using the existing 'name_entry *p' value in
'unpack_callback()', which points to the first non-empty entry in 'names'.
Because 'p' is 'const', also update 'is_sparse_directory_entry()'s
'name_entry *' argument to be 'const'.

Finally, add a regression test case.

Reported-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Victoria Dye <vdye@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/t/t1092-sparse-checkout-compatibility.sh b/t/t1092-sparse-checkout-compatibility.sh
index 5dced39889fff99335148bd00f900fab4038622d..16abac5d2bd4143ea3040213fd07391e69f5eb99 100755 (executable)
--- a/t/t1092-sparse-checkout-compatibility.sh
+++ b/t/t1092-sparse-checkout-compatibility.sh
@@ -380,6 +380,15 @@ test_expect_success 'checkout with modified sparse directory' '
        test_all_match git checkout base
 '
 
+test_expect_success 'checkout orphan then non-orphan' '
+       init_repos &&
+
+       test_all_match git checkout --orphan test-orphan &&
+       test_all_match git status --porcelain=v2 &&
+       test_all_match git checkout base &&
+       test_all_match git status --porcelain=v2
+'
+
 test_expect_success 'add outside sparse cone' '
        init_repos &&
 

diff --git a/unpack-trees.c b/unpack-trees.c
index 9ac7783e2e0ca97e3c972e7258a2131580086327..88a76f19a3bb0db3995a40cab7eb52e1469b25ac 100644 (file)
--- a/unpack-trees.c
+++ b/unpack-trees.c
@@ -1423,7 +1423,7 @@ static void debug_unpack_callback(int n,
  * from the tree walk at the given traverse_info.
  */
 static int is_sparse_directory_entry(struct cache_entry *ce,
-                                    struct name_entry *name,
+                                    const struct name_entry *name,
                                     struct traverse_info *info)
 {
        if (!ce || !name || !S_ISSPARSEDIR(ce->ce_mode))
@@ -1562,7 +1562,7 @@ static int unpack_callback(int n, unsigned long mask, unsigned long dirmask, str
                        }
                }
 
-               if (!is_sparse_directory_entry(src[0], names, info) &&
+               if (!is_sparse_directory_entry(src[0], p, info) &&
                    !is_new_sparse_dir &&
                    traverse_trees_recursive(n, dirmask, mask & ~dirmask,
                                                    names, info) < 0) {