read-tree: narrow scope of index expansion for '--prefix'
When 'git read-tree' is provided with a prefix, expand the index only if the
prefix is equivalent to a sparse directory or contained within one. If the
index is not expanded in these cases, 'ce_in_traverse_path' will indicate
that the relevant sparse directory is not in the prefix/traverse path,
skipping past it and not unpacking the appropriate tree(s).
If the prefix is in-cone, its sparse subdirectories (if any) will be
traversed correctly without index expansion.
The behavior of 'git read-tree' with prefixes 1) inside of cone, 2) equal to
a sparse directory, and 3) inside a sparse directory are all tested as part
of the 't/t1092-sparse-checkout-compatibility.sh' test 'read-tree --prefix',
ensuring that the sparse index case works the way it did prior to this
change as well as matching non-sparse index sparse-checkout.
Helped-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Victoria Dye <vdye@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/unpack-trees.c b/unpack-trees.c
index 360844b..f3667d8 100644
--- a/unpack-trees.c
+++ b/unpack-trees.c
@@ -1693,6 +1693,41 @@ static void populate_from_existing_patterns(struct unpack_trees_options *o,
o->pl = pl;
}
+static void update_sparsity_for_prefix(const char *prefix,
+ struct index_state *istate)
+{
+ int prefix_len = strlen(prefix);
+ struct strbuf ce_prefix = STRBUF_INIT;
+
+ if (!istate->sparse_index)
+ return;
+
+ while (prefix_len > 0 && prefix[prefix_len - 1] == '/')
+ prefix_len--;
+
+ if (prefix_len <= 0)
+ BUG("Invalid prefix passed to update_sparsity_for_prefix");
+
+ strbuf_grow(&ce_prefix, prefix_len + 1);
+ strbuf_add(&ce_prefix, prefix, prefix_len);
+ strbuf_addch(&ce_prefix, '/');
+
+ /*
+ * If the prefix points to a sparse directory or a path inside a sparse
+ * directory, the index should be expanded. This is accomplished in one
+ * of two ways:
+ * - if the prefix is inside a sparse directory, it will be expanded by
+ * the 'ensure_full_index(...)' call in 'index_name_pos(...)'.
+ * - if the prefix matches an existing sparse directory entry,
+ * 'index_name_pos(...)' will return its index position, triggering
+ * the 'ensure_full_index(...)' below.
+ */
+ if (!path_in_cone_mode_sparse_checkout(ce_prefix.buf, istate) &&
+ index_name_pos(istate, ce_prefix.buf, ce_prefix.len) >= 0)
+ ensure_full_index(istate);
+
+ strbuf_release(&ce_prefix);
+}
static int verify_absent(const struct cache_entry *,
enum unpack_trees_error_types,
@@ -1739,6 +1774,9 @@ int unpack_trees(unsigned len, struct tree_desc *t, struct unpack_trees_options
setup_standard_excludes(o->dir);
}
+ if (o->prefix)
+ update_sparsity_for_prefix(o->prefix, o->src_index);
+
if (!core_apply_sparse_checkout || !o->update)
o->skip_sparse_checkout = 1;
if (!o->skip_sparse_checkout && !o->pl) {
