Fix iterators based on pull request feedback

This update addresses all of the feedback in pull request #570.

The biggest change was to create actual linked list stacks for
storing the tree and workdir iterator state.  This cleaned up
the code a ton.  Additionally, all of the static functions had
their 'git_' prefix removed, and a lot of other unnecessary
changes were removed from the original patch.

1 files changed, 201 insertions, 230 deletions

diff --git a/src/iterator.c b/src/iterator.c
index 805ff643e..c2b88ab84 100644
--- a/src/iterator.c
+++ b/src/iterator.c
@@ -10,36 +10,33 @@
 #include "ignore.h"
 #include "buffer.h"
 
-#define IDX_AS_PTR(I)		(void *)((uint64_t)(I))
-#define PTR_AS_IDX(P)		(unsigned int)((uint64_t)(P))
+typedef struct tree_iterator_frame tree_iterator_frame;
+struct tree_iterator_frame {
+	tree_iterator_frame *next;
+	git_tree *tree;
+	unsigned int index;
+};
 
 typedef struct {
-	git_iterator cb;
+	git_iterator base;
 	git_repository *repo;
-	git_vector tree_stack;
-	git_vector idx_stack;
+	tree_iterator_frame *stack;
 	git_index_entry entry;
 	git_buf path;
-} git_iterator_tree;
+} tree_iterator;
 
-static const git_tree_entry *git_iterator__tree_entry(git_iterator_tree *ti)
+static const git_tree_entry *tree_iterator__tree_entry(tree_iterator *ti)
 {
-	git_tree *tree;
-	unsigned int tree_idx;
-
-	if ((tree = git_vector_last(&ti->tree_stack)) == NULL)
-		return NULL;
-
-	tree_idx = PTR_AS_IDX(git_vector_last(&ti->idx_stack));
-	return git_tree_entry_byindex(tree, tree_idx);
+	return (ti->stack == NULL) ? NULL :
+		git_tree_entry_byindex(ti->stack->tree, ti->stack->index);
 }
 
-static int git_iterator__tree_current(
+static int tree_iterator__current(
 	git_iterator *self, const git_index_entry **entry)
 {
 	int error;
-	git_iterator_tree *ti = (git_iterator_tree *)self;
-	const git_tree_entry *te = git_iterator__tree_entry(ti);
+	tree_iterator *ti = (tree_iterator *)self;
+	const git_tree_entry *te = tree_iterator__tree_entry(ti);
 
 	*entry = NULL;
 
@@ -58,132 +55,111 @@ static int git_iterator__tree_current(
 	return GIT_SUCCESS;
 }
 
-static int git_iterator__tree_at_end(git_iterator *self)
+static int tree_iterator__at_end(git_iterator *self)
 {
-	git_iterator_tree *ti = (git_iterator_tree *)self;
-	git_tree *tree;
-	return ((tree = git_vector_last(&ti->tree_stack)) == NULL ||
-			git_tree_entry_byindex(
-				tree, PTR_AS_IDX(git_vector_last(&ti->idx_stack))) == NULL);
+	return (tree_iterator__tree_entry((tree_iterator *)self) == NULL);
 }
 
-static int expand_tree_if_needed(git_iterator_tree *ti)
+static tree_iterator_frame *tree_iterator__alloc_frame(git_tree *tree)
 {
-	int error;
-	git_tree *tree, *subtree;
-	unsigned int tree_idx;
-	const git_tree_entry *te;
-
-	while (1) {
-		tree = git_vector_last(&ti->tree_stack);
-		tree_idx = PTR_AS_IDX(git_vector_last(&ti->idx_stack));
-		te = git_tree_entry_byindex(tree, tree_idx);
+	tree_iterator_frame *tf = git__calloc(1, sizeof(tree_iterator_frame));
+	tf->tree = tree;
+	return tf;
+}
 
-		if (!entry_is_tree(te))
-			break;
+static int tree_iterator__expand_tree(tree_iterator *ti)
+{
+	int error;
+	git_tree *subtree;
+	const git_tree_entry *te = tree_iterator__tree_entry(ti);
+	tree_iterator_frame *tf;
 
+	while (te != NULL && entry_is_tree(te)) {
 		error = git_tree_lookup(&subtree, ti->repo, &te->oid);
 		if (error != GIT_SUCCESS)
 			return error;
 
-		if ((error = git_vector_insert(&ti->tree_stack, subtree)) < GIT_SUCCESS ||
-			(error = git_vector_insert(&ti->idx_stack, IDX_AS_PTR(0))) < GIT_SUCCESS ||
-			(error = git_buf_joinpath(&ti->path, ti->path.ptr, te->filename)) < GIT_SUCCESS)
-		{
-			git_tree_free(subtree);
+		if ((tf = tree_iterator__alloc_frame(subtree)) == NULL)
+			return GIT_ENOMEM;
+
+		tf->next  = ti->stack;
+		ti->stack = tf;
+
+		error = git_buf_joinpath(&ti->path, ti->path.ptr, te->filename);
+		if (error < GIT_SUCCESS)
 			return error;
-		}
+
+		te = tree_iterator__tree_entry(ti);
 	}
 
 	return GIT_SUCCESS;
 }
 
-static int git_iterator__tree_advance(
+static void tree_iterator__pop_frame(tree_iterator *ti)
+{
+	tree_iterator_frame *tf = ti->stack;
+	ti->stack = tf->next;
+	if (ti->stack != NULL) /* don't free the initial tree */
+		git_tree_free(tf->tree);
+	git__free(tf);
+}
+
+static int tree_iterator__advance(
 	git_iterator *self, const git_index_entry **entry)
 {
 	int error = GIT_SUCCESS;
-	git_iterator_tree *ti = (git_iterator_tree *)self;
-	git_tree *tree = git_vector_last(&ti->tree_stack);
-	unsigned int tree_idx = PTR_AS_IDX(git_vector_last(&ti->idx_stack));
-	const git_tree_entry *te = git_tree_entry_byindex(tree, tree_idx);
+	tree_iterator *ti = (tree_iterator *)self;
+	const git_tree_entry *te;
 
 	if (entry != NULL)
 		*entry = NULL;
 
-	if (te == NULL)
-		return GIT_SUCCESS;
-
-	while (1) {
-		/* advance this tree */
-		tree_idx++;
-		ti->idx_stack.contents[ti->idx_stack.length - 1] = IDX_AS_PTR(tree_idx);
-
+	while (ti->stack != NULL) {
 		/* remove old entry filename */
 		git_buf_rtruncate_at_char(&ti->path, '/');
 
-		if ((te = git_tree_entry_byindex(tree, tree_idx)) != NULL)
+		te = git_tree_entry_byindex(ti->stack->tree, ++ti->stack->index);
+		if (te != NULL)
 			break;
 
-		/* no entry - either we are done or we are done with this subtree */
-		if (ti->tree_stack.length == 1)
-			return GIT_SUCCESS;
-
-		git_tree_free(tree);
-		git_vector_remove(&ti->tree_stack, ti->tree_stack.length - 1);
-		git_vector_remove(&ti->idx_stack, ti->idx_stack.length - 1);
+		tree_iterator__pop_frame(ti);
 		git_buf_rtruncate_at_char(&ti->path, '/');
-
-		tree = git_vector_last(&ti->tree_stack);
-		tree_idx = PTR_AS_IDX(git_vector_last(&ti->idx_stack));
 	}
 
 	if (te && entry_is_tree(te))
-		error = expand_tree_if_needed(ti);
+		error = tree_iterator__expand_tree(ti);
 
 	if (error == GIT_SUCCESS && entry != NULL)
-		error = git_iterator__tree_current(self, entry);
+		error = tree_iterator__current(self, entry);
 
 	return error;
 }
 
-static void git_iterator__tree_free(git_iterator *self)
+static void tree_iterator__free(git_iterator *self)
 {
-	git_iterator_tree *ti = (git_iterator_tree *)self;
-
-	while (ti->tree_stack.length > 1) {
-		git_tree *tree = git_vector_last(&ti->tree_stack);
-		git_tree_free(tree);
-		git_vector_remove(&ti->tree_stack, ti->tree_stack.length - 1);
-	}
-
-	git_vector_clear(&ti->tree_stack);
-	git_vector_clear(&ti->idx_stack);
+	tree_iterator *ti = (tree_iterator *)self;
+	while (ti->stack != NULL)
+		tree_iterator__pop_frame(ti);
 	git_buf_free(&ti->path);
 }
 
-int git_iterator_for_tree(git_repository *repo, git_tree *tree, git_iterator **iter)
+int git_iterator_for_tree(
+	git_repository *repo, git_tree *tree, git_iterator **iter)
 {
 	int error;
-	git_iterator_tree *ti = git__calloc(1, sizeof(git_iterator_tree));
+	tree_iterator *ti = git__calloc(1, sizeof(tree_iterator));
 	if (!ti)
 		return GIT_ENOMEM;
 
-	ti->cb.type    = GIT_ITERATOR_TREE;
-	ti->cb.current = git_iterator__tree_current;
-	ti->cb.at_end  = git_iterator__tree_at_end;
-	ti->cb.advance = git_iterator__tree_advance;
-	ti->cb.free    = git_iterator__tree_free;
-	ti->repo       = repo;
-
-	if (!(error = git_vector_init(&ti->tree_stack, 0, NULL)) &&
-		!(error = git_vector_insert(&ti->tree_stack, tree)) &&
-		!(error = git_vector_init(&ti->idx_stack, 0, NULL)))
-		error   = git_vector_insert(&ti->idx_stack, IDX_AS_PTR(0));
+	ti->base.type    = GIT_ITERATOR_TREE;
+	ti->base.current = tree_iterator__current;
+	ti->base.at_end  = tree_iterator__at_end;
+	ti->base.advance = tree_iterator__advance;
+	ti->base.free    = tree_iterator__free;
+	ti->repo         = repo;
+	ti->stack        = tree_iterator__alloc_frame(tree);
 
-	if (error == GIT_SUCCESS)
-		error = expand_tree_if_needed(ti);
-
-	if (error != GIT_SUCCESS)
+	if ((error = tree_iterator__expand_tree(ti)) < GIT_SUCCESS)
 		git_iterator_free((git_iterator *)ti);
 	else
 		*iter = (git_iterator *)ti;
@@ -193,29 +169,29 @@ int git_iterator_for_tree(git_repository *repo, git_tree *tree, git_iterator **i
 
 
 typedef struct {
-	git_iterator cb;
+	git_iterator base;
 	git_index *index;
 	unsigned int current;
-} git_iterator_index;
+} index_iterator;
 
-static int git_iterator__index_current(
+static int index_iterator__current(
 	git_iterator *self, const git_index_entry **entry)
 {
-	git_iterator_index *ii = (git_iterator_index *)self;
+	index_iterator *ii = (index_iterator *)self;
 	*entry = git_index_get(ii->index, ii->current);
 	return GIT_SUCCESS;
 }
 
-static int git_iterator__index_at_end(git_iterator *self)
+static int index_iterator__at_end(git_iterator *self)
 {
-	git_iterator_index *ii = (git_iterator_index *)self;
+	index_iterator *ii = (index_iterator *)self;
 	return (ii->current >= git_index_entrycount(ii->index));
 }
 
-static int git_iterator__index_advance(
+static int index_iterator__advance(
 	git_iterator *self, const git_index_entry **entry)
 {
-	git_iterator_index *ii = (git_iterator_index *)self;
+	index_iterator *ii = (index_iterator *)self;
 	if (ii->current < git_index_entrycount(ii->index))
 		ii->current++;
 	if (entry)
@@ -223,9 +199,9 @@ static int git_iterator__index_advance(
 	return GIT_SUCCESS;
 }
 
-static void git_iterator__index_free(git_iterator *self)
+static void index_iterator__free(git_iterator *self)
 {
-	git_iterator_index *ii = (git_iterator_index *)self;
+	index_iterator *ii = (index_iterator *)self;
 	git_index_free(ii->index);
 	ii->index = NULL;
 }
@@ -233,16 +209,16 @@ static void git_iterator__index_free(git_iterator *self)
 int git_iterator_for_index(git_repository *repo, git_iterator **iter)
 {
 	int error;
-	git_iterator_index *ii = git__calloc(1, sizeof(git_iterator_index));
+	index_iterator *ii = git__calloc(1, sizeof(index_iterator));
 	if (!ii)
 		return GIT_ENOMEM;
 
-	ii->cb.type    = GIT_ITERATOR_INDEX;
-	ii->cb.current = git_iterator__index_current;
-	ii->cb.at_end  = git_iterator__index_at_end;
-	ii->cb.advance = git_iterator__index_advance;
-	ii->cb.free    = git_iterator__index_free;
-	ii->current    = 0;
+	ii->base.type    = GIT_ITERATOR_INDEX;
+	ii->base.current = index_iterator__current;
+	ii->base.at_end  = index_iterator__at_end;
+	ii->base.advance = index_iterator__advance;
+	ii->base.free    = index_iterator__free;
+	ii->current      = 0;
 
 	if ((error = git_repository_index(&ii->index, repo)) < GIT_SUCCESS)
 		git__free(ii);
@@ -252,101 +228,107 @@ int git_iterator_for_index(git_repository *repo, git_iterator **iter)
 }
 
 
+typedef struct workdir_iterator_frame workdir_iterator_frame;
+struct workdir_iterator_frame {
+	workdir_iterator_frame *next;
+	git_vector entries;
+	unsigned int index;
+};
+
 typedef struct {
-	git_iterator cb;
+	git_iterator base;
 	git_repository *repo;
 	size_t root_len;
-	git_vector dir_stack; /* vector of vectors of paths */
-	git_vector idx_stack;
+	workdir_iterator_frame *stack;
 	git_ignores ignores;
 	git_index_entry entry;
 	git_buf path;
 	int is_ignored;
-} git_iterator_workdir;
+} workdir_iterator;
+
+static workdir_iterator_frame *workdir_iterator__alloc_frame(void)
+{
+	workdir_iterator_frame *wf = git__calloc(1, sizeof(workdir_iterator_frame));
+	if (wf == NULL)
+		return wf;
+	if (git_vector_init(&wf->entries, 0, git__strcmp_cb) != GIT_SUCCESS) {
+		git__free(wf);
+		return NULL;
+	}
+	return wf;
+}
 
-static void free_directory(git_vector *dir)
+static void workdir_iterator__free_frame(workdir_iterator_frame *wf)
 {
 	unsigned int i;
 	char *path;
 
-	git_vector_foreach(dir, i, path)
+	git_vector_foreach(&wf->entries, i, path)
 		git__free(path);
-	git_vector_free(dir);
-	git__free(dir);
+	git_vector_free(&wf->entries);
+	git__free(wf);
 }
 
-static int load_workdir_entry(git_iterator_workdir *wi);
+static int workdir_iterator__update_entry(workdir_iterator *wi);
 
-static int push_directory(git_iterator_workdir *wi)
+static int workdir_iterator__expand_dir(workdir_iterator *wi)
 {
 	int error;
-	git_vector *dir = NULL;
-
-	error = git_vector_alloc(&dir, 0, git__strcmp_cb);
-	if (error < GIT_SUCCESS)
-		return error;
+	workdir_iterator_frame *wf = workdir_iterator__alloc_frame();
+	if (wf == NULL)
+		return GIT_ENOMEM;
 
-	/* allocate dir entries with extra byte (the "1" param) so later on we
-	 * can suffix directories with a "/" as needed.
+	/* allocate dir entries with extra byte (the "1" param) so we
+	 * can suffix directory names with a "/".
 	 */
-	error = git_path_dirload(wi->path.ptr, wi->root_len, 1, dir);
-	if (error < GIT_SUCCESS || dir->length == 0) {
-		free_directory(dir);
+	error = git_path_dirload(wi->path.ptr, wi->root_len, 1, &wf->entries);
+	if (error < GIT_SUCCESS || wf->entries.length == 0) {
+		workdir_iterator__free_frame(wf);
 		return GIT_ENOTFOUND;
 	}
 
-	if ((error = git_vector_insert(&wi->dir_stack, dir)) ||
-		(error = git_vector_insert(&wi->idx_stack, IDX_AS_PTR(0))))
-	{
-		free_directory(dir);
-		return error;
-	}
-
-	git_vector_sort(dir);
+	git_vector_sort(&wf->entries);
+	wf->next  = wi->stack;
+	wi->stack = wf;
 
-	if (wi->dir_stack.length > 1) {
+	/* only push new ignores if this is not top level directory */
+	if (wi->stack->next != NULL) {
 		int slash_pos = git_buf_rfind_next(&wi->path, '/');
 		(void)git_ignore__push_dir(&wi->ignores, &wi->path.ptr[slash_pos + 1]);
 	}
 
-	return load_workdir_entry(wi);
+	return workdir_iterator__update_entry(wi);
 }
 
-static int git_iterator__workdir_current(
+static int workdir_iterator__current(
 	git_iterator *self, const git_index_entry **entry)
 {
-	git_iterator_workdir *wi = (git_iterator_workdir *)self;
+	workdir_iterator *wi = (workdir_iterator *)self;
 	*entry = (wi->entry.path == NULL) ? NULL : &wi->entry;
 	return GIT_SUCCESS;
 }
 
-static int git_iterator__workdir_at_end(git_iterator *self)
+static int workdir_iterator__at_end(git_iterator *self)
 {
-	git_iterator_workdir *wi = (git_iterator_workdir *)self;
-	return (wi->entry.path == NULL);
+	return (((workdir_iterator *)self)->entry.path == NULL);
 }
 
-static int git_iterator__workdir_advance(
+static int workdir_iterator__advance(
 	git_iterator *self, const git_index_entry **entry)
 {
 	int error;
-	git_iterator_workdir *wi = (git_iterator_workdir *)self;
-	git_vector *dir;
-	unsigned int pos;
+	workdir_iterator *wi = (workdir_iterator *)self;
+	workdir_iterator_frame *wf;
 	const char *next;
 
-	if (entry)
+	if (entry != NULL)
 		*entry = NULL;
 
 	if (wi->entry.path == NULL)
 		return GIT_SUCCESS;
 
-	while (1) {
-		dir = git_vector_last(&wi->dir_stack);
-		pos = 1 + PTR_AS_IDX(git_vector_last(&wi->idx_stack));
-		wi->idx_stack.contents[wi->idx_stack.length - 1] = IDX_AS_PTR(pos);
-
-		next = git_vector_get(dir, pos);
+	while ((wf = wi->stack) != NULL) {
+		next = git_vector_get(&wf->entries, ++wf->index);
 		if (next != NULL) {
 			if (strcmp(next, DOT_GIT) == 0)
 				continue;
@@ -354,69 +336,45 @@ static int git_iterator__workdir_advance(
 			break;
 		}
 
-		memset(&wi->entry, 0, sizeof(wi->entry));
-		if (wi->dir_stack.length == 1)
-			return GIT_SUCCESS;
-
-		free_directory(dir);
-		git_vector_remove(&wi->dir_stack, wi->dir_stack.length - 1);
-		git_vector_remove(&wi->idx_stack, wi->idx_stack.length - 1);
+		/* pop workdir directory stack */
+		wi->stack = wf->next;
+		workdir_iterator__free_frame(wf);
 		git_ignore__pop_dir(&wi->ignores);
+
+		if (wi->stack == NULL) {
+			memset(&wi->entry, 0, sizeof(wi->entry));
+			return GIT_SUCCESS;
+		}
 	}
 
-	error = load_workdir_entry(wi);
+	error = workdir_iterator__update_entry(wi);
 
-	if (error == GIT_SUCCESS && entry)
-		return git_iterator__workdir_current(self, entry);
+	if (error == GIT_SUCCESS && entry != NULL)
+		error = workdir_iterator__current(self, entry);
 
 	return error;
 }
 
-int git_iterator_advance_into_directory(
-	git_iterator *iter, const git_index_entry **entry)
+static void workdir_iterator__free(git_iterator *self)
 {
-	git_iterator_workdir *wi = (git_iterator_workdir *)iter;
-
-	if (iter->type != GIT_ITERATOR_WORKDIR)
-		return git_iterator_current(iter, entry);
+	workdir_iterator *wi = (workdir_iterator *)self;
 
-	/* Loop because the first entry in the ignored directory could itself be
-	 * an ignored directory, but we want to descend to find an actual entry.
-	 */
-	if (wi->entry.path && S_ISDIR(wi->entry.mode)) {
-		if (push_directory(wi) < GIT_SUCCESS)
-			/* If error loading or if empty, skip the directory. */
-			return git_iterator__workdir_advance((git_iterator *)wi, entry);
+	while (wi->stack != NULL) {
+		workdir_iterator_frame *wf = wi->stack;
+		wi->stack = wf->next;
+		workdir_iterator__free_frame(wf);
 	}
 
-	return git_iterator__workdir_current(iter, entry);
-}
-
-static void git_iterator__workdir_free(git_iterator *self)
-{
-	git_iterator_workdir *wi = (git_iterator_workdir *)self;
-
-	while (wi->dir_stack.length) {
-		git_vector *dir = git_vector_last(&wi->dir_stack);
-		free_directory(dir);
-		git_vector_remove(&wi->dir_stack, wi->dir_stack.length - 1);
-	}
-
-	git_vector_clear(&wi->dir_stack);
-	git_vector_clear(&wi->idx_stack);
 	git_ignore__free(&wi->ignores);
 	git_buf_free(&wi->path);
 }
 
-static int load_workdir_entry(git_iterator_workdir *wi)
+static int workdir_iterator__update_entry(workdir_iterator *wi)
 {
 	int error;
-	char *relpath;
-	git_vector *dir = git_vector_last(&wi->dir_stack);
-	unsigned int pos = PTR_AS_IDX(git_vector_last(&wi->idx_stack));
 	struct stat st;
+	char *relpath = git_vector_get(&wi->stack->entries, wi->stack->index);
 
-	relpath = git_vector_get(dir, pos);
 	error = git_buf_joinpath(
 		&wi->path, git_repository_workdir(wi->repo), relpath);
 	if (error < GIT_SUCCESS)
@@ -425,14 +383,12 @@ static int load_workdir_entry(git_iterator_workdir *wi)
 	memset(&wi->entry, 0, sizeof(wi->entry));
 	wi->entry.path = relpath;
 
+	/* skip over .git directory */
 	if (strcmp(relpath, DOT_GIT) == 0)
-		return git_iterator__workdir_advance((git_iterator *)wi, NULL);
+		return workdir_iterator__advance((git_iterator *)wi, NULL);
 
 	/* if there is an error processing the entry, treat as ignored */
 	wi->is_ignored = 1;
-	error = git_ignore__lookup(&wi->ignores, wi->entry.path, &wi->is_ignored);
-	if (error != GIT_SUCCESS)
-		return GIT_SUCCESS;
 
 	if (p_lstat(wi->path.ptr, &st) < 0)
 		return GIT_SUCCESS;
@@ -451,6 +407,11 @@ static int load_workdir_entry(git_iterator_workdir *wi)
 	if (st.st_mode == 0)
 		return GIT_SUCCESS;
 
+	/* okay, we are far enough along to look up real ignore rule */
+	error = git_ignore__lookup(&wi->ignores, wi->entry.path, &wi->is_ignored);
+	if (error != GIT_SUCCESS)
+		return GIT_SUCCESS;
+
 	if (S_ISDIR(st.st_mode)) {
 		if (git_path_contains(&wi->path, DOT_GIT) == GIT_SUCCESS) {
 			/* create submodule entry */
@@ -470,30 +431,28 @@ static int load_workdir_entry(git_iterator_workdir *wi)
 int git_iterator_for_workdir(git_repository *repo, git_iterator **iter)
 {
 	int error;
-	git_iterator_workdir *wi = git__calloc(1, sizeof(git_iterator_workdir));
+	workdir_iterator *wi = git__calloc(1, sizeof(workdir_iterator));
 	if (!wi)
 		return GIT_ENOMEM;
 
-	wi->cb.type    = GIT_ITERATOR_WORKDIR;
-	wi->cb.current = git_iterator__workdir_current;
-	wi->cb.at_end  = git_iterator__workdir_at_end;
-	wi->cb.advance = git_iterator__workdir_advance;
-	wi->cb.free    = git_iterator__workdir_free;
-	wi->repo       = repo;
-
-	if ((error = git_buf_sets(
-			&wi->path, git_repository_workdir(repo))) < GIT_SUCCESS ||
-		(error = git_vector_init(&wi->dir_stack, 0, NULL)) < GIT_SUCCESS ||
-		(error = git_vector_init(&wi->idx_stack, 0, NULL)) < GIT_SUCCESS ||
-		(error = git_ignore__for_path(repo, "", &wi->ignores)) < GIT_SUCCESS)
-	{
+	wi->base.type    = GIT_ITERATOR_WORKDIR;
+	wi->base.current = workdir_iterator__current;
+	wi->base.at_end  = workdir_iterator__at_end;
+	wi->base.advance = workdir_iterator__advance;
+	wi->base.free    = workdir_iterator__free;
+	wi->repo         = repo;
+
+	error = git_buf_sets(&wi->path, git_repository_workdir(repo));
+	if (error == GIT_SUCCESS)
+		error = git_ignore__for_path(repo, "", &wi->ignores);
+	if (error != GIT_SUCCESS) {
 		git__free(wi);
 		return error;
 	}
 
 	wi->root_len = wi->path.size;
 
-	if ((error = push_directory(wi)) < GIT_SUCCESS)
+	if ((error = workdir_iterator__expand_dir(wi)) < GIT_SUCCESS)
 		git_iterator_free((git_iterator *)wi);
 	else
 		*iter = (git_iterator *)wi;
@@ -501,21 +460,33 @@ int git_iterator_for_workdir(git_repository *repo, git_iterator **iter)
 	return error;
 }
 
+
 int git_iterator_current_tree_entry(
 	git_iterator *iter, const git_tree_entry **tree_entry)
 {
-	if (iter->type != GIT_ITERATOR_TREE)
-		*tree_entry = NULL;
-	else
-		*tree_entry = git_iterator__tree_entry((git_iterator_tree *)iter);
-
+	*tree_entry = (iter->type != GIT_ITERATOR_TREE) ? NULL :
+		tree_iterator__tree_entry((tree_iterator *)iter);
 	return GIT_SUCCESS;
 }
 
 int git_iterator_current_is_ignored(git_iterator *iter)
 {
-	if (iter->type != GIT_ITERATOR_WORKDIR)
-		return 0;
-	else
-		return ((git_iterator_workdir *)iter)->is_ignored;
+	return (iter->type != GIT_ITERATOR_WORKDIR) ? 0 :
+		((workdir_iterator *)iter)->is_ignored;
+}
+
+int git_iterator_advance_into_directory(
+	git_iterator *iter, const git_index_entry **entry)
+{
+	workdir_iterator *wi = (workdir_iterator *)iter;
+
+	if (iter->type == GIT_ITERATOR_WORKDIR &&
+		wi->entry.path && S_ISDIR(wi->entry.mode))
+	{
+		if (workdir_iterator__expand_dir(wi) < GIT_SUCCESS)
+			/* if error loading or if empty, skip the directory. */
+			return workdir_iterator__advance(iter, entry);
+	}
+
+	return entry ? git_iterator_current(iter, entry) : GIT_SUCCESS;
 }