Make workdir iterator use filesystem iterator

This adds some hooks into the filesystem iterator so that the
workdir iterator can just become a wrapper around it.  Then we
remove most of the workdir iterator code and just have it augment
the filesystem iterator with skipping .git entries, updating the
ignore stack, and checking for submodules.

1 files changed, 154 insertions, 391 deletions

diff --git a/src/iterator.c b/src/iterator.c
index dd8a6133d..6eee5a805 100644
--- a/src/iterator.c
+++ b/src/iterator.c
@@ -26,8 +26,6 @@
 	(GIT_ITERATOR_IGNORE_CASE | GIT_ITERATOR_DONT_IGNORE_CASE)
 
 #define ITERATOR_BASE_INIT(P,NAME_LC,NAME_UC,REPO) do { \
-	(P) = git__calloc(1, sizeof(NAME_LC ## _iterator)); \
-	GITERR_CHECK_ALLOC(P); \
 	(P)->base.type    = GIT_ITERATOR_TYPE_ ## NAME_UC; \
 	(P)->base.cb      = &(P)->cb; \
 	ITERATOR_SET_CB(P,NAME_LC); \
@@ -148,7 +146,8 @@ int git_iterator_for_nothing(
 	const char *start,
 	const char *end)
 {
-	empty_iterator *i;
+	empty_iterator *i = git__calloc(1, sizeof(empty_iterator));
+	GITERR_CHECK_ALLOC(i);
 
 #define empty_iterator__current empty_iterator__noop
 #define empty_iterator__advance empty_iterator__noop
@@ -581,6 +580,9 @@ int git_iterator_for_tree(
 	if ((error = git_object_dup((git_object **)&tree, (git_object *)tree)) < 0)
 		return error;
 
+	ti = git__calloc(1, sizeof(tree_iterator));
+	GITERR_CHECK_ALLOC(ti);
+
 	ITERATOR_BASE_INIT(ti, tree, TREE, git_tree_owner(tree));
 
 	if ((error = iterator__update_ignore_case((git_iterator *)ti, flags)) < 0)
@@ -810,7 +812,8 @@ int git_iterator_for_index(
 	const char *start,
 	const char *end)
 {
-	index_iterator *ii;
+	index_iterator *ii = git__calloc(1, sizeof(index_iterator));
+	GITERR_CHECK_ALLOC(ii);
 
 	ITERATOR_BASE_INIT(ii, index, INDEX, git_index_owner(index));
 
@@ -840,7 +843,8 @@ struct fs_iterator_frame {
 	size_t index;
 };
 
-typedef struct {
+typedef struct fs_iterator fs_iterator;
+struct fs_iterator {
 	git_iterator base;
 	git_iterator_callbacks cb;
 	fs_iterator_frame *stack;
@@ -848,7 +852,11 @@ typedef struct {
 	git_buf path;
 	size_t root_len;
 	int depth;
-} fs_iterator;
+
+	int (*frame_added)(fs_iterator *self);
+	int (*frame_removed)(fs_iterator *self);
+	int (*entry_updated)(fs_iterator *self);
+};
 
 #define FS_MAX_DEPTH 100
 
@@ -867,15 +875,31 @@ static fs_iterator_frame *fs_iterator__alloc_frame(fs_iterator *fi)
 	return ff;
 }
 
-static void fs_iterator__free_frame(fs_iterator_frame *ff)
+static void fs_iterator__pop_frame(
+	fs_iterator *fi, fs_iterator_frame *ff, bool pop_last)
 {
 	size_t i;
 	git_path_with_stat *path;
+	fs_iterator_frame *ff_next = ff->next;
+
+	if (fi && !ff_next && !pop_last) {
+		memset(&fi->entry, 0, sizeof(fi->entry));
+		return;
+	}
 
 	git_vector_foreach(&ff->entries, i, path)
 		git__free(path);
 	git_vector_free(&ff->entries);
 	git__free(ff);
+
+	if (!fi || fi->stack != ff)
+		return;
+
+	fi->stack = ff_next;
+	fi->depth--;
+
+	if (fi->frame_removed)
+		fi->frame_removed(fi);
 }
 
 static int fs_iterator__update_entry(fs_iterator *fi);
@@ -913,14 +937,14 @@ static int fs_iterator__expand_dir(fs_iterator *fi)
 		fi->base.start, fi->base.end, &ff->entries);
 
 	if (error < 0 || ff->entries.length == 0) {
-		fs_iterator__free_frame(ff);
+		fs_iterator__pop_frame(NULL, ff, true);
 		return GIT_ENOTFOUND;
 	}
 
 	if (++(fi->depth) > FS_MAX_DEPTH) {
 		giterr_set(GITERR_REPOSITORY,
 			"Directory nesting is too deep (%d)", fi->depth);
-		fs_iterator__free_frame(ff);
+		fs_iterator__pop_frame(NULL, ff, true);
 		return -1;
 	}
 
@@ -929,6 +953,9 @@ static int fs_iterator__expand_dir(fs_iterator *fi)
 	ff->next  = fi->stack;
 	fi->stack = ff;
 
+	if (fi->frame_added && (error = fi->frame_added(fi)) < 0)
+		return error;
+
 	return fs_iterator__update_entry(fi);
 }
 
@@ -971,7 +998,7 @@ static int fs_iterator__advance_into(
 	return error;
 }
 
-static int fs_iterator__advance(
+static int fs_iterator__advance_over(
 	const git_index_entry **entry, git_iterator *self)
 {
 	int error = 0;
@@ -979,20 +1006,6 @@ static int fs_iterator__advance(
 	fs_iterator_frame *ff;
 	git_path_with_stat *next;
 
-	/* given include_trees & autoexpand, we might have to go into a tree */
-	if (iterator__do_autoexpand(fi) &&
-		fi->entry.path != NULL &&
-		fi->entry.mode == GIT_FILEMODE_TREE)
-	{
-		error = fs_iterator__advance_into(entry, self);
-
-		/* continue silently past empty directories if autoexpanding */
-		if (error != GIT_ENOTFOUND)
-			return error;
-		giterr_clear();
-		error = 0;
-	}
-
 	if (entry != NULL)
 		*entry = NULL;
 
@@ -1003,15 +1016,7 @@ static int fs_iterator__advance(
 		if (next != NULL)
 			break;
 
-		/* pop stack if anything is left to pop */
-		if (!ff->next) {
-			memset(&fi->entry, 0, sizeof(fi->entry));
-			return 0;
-		}
-
-		fi->stack = ff->next;
-		fi->depth--;
-		fs_iterator__free_frame(ff);
+		fs_iterator__pop_frame(fi, ff, false);
 	}
 
 	error = fs_iterator__update_entry(fi);
@@ -1022,6 +1027,26 @@ static int fs_iterator__advance(
 	return error;
 }
 
+static int fs_iterator__advance(
+	const git_index_entry **entry, git_iterator *self)
+{
+	fs_iterator *fi = (fs_iterator *)self;
+
+	/* given include_trees & autoexpand, we might have to go into a tree */
+	if (iterator__do_autoexpand(fi) &&
+		fi->entry.path != NULL &&
+		fi->entry.mode == GIT_FILEMODE_TREE)
+	{
+		int error = fs_iterator__advance_into(entry, self);
+		if (error != GIT_ENOTFOUND)
+			return error;
+		/* continue silently past empty directories if autoexpanding */
+		giterr_clear();
+	}
+
+	return fs_iterator__advance_over(entry, self);
+}
+
 static int fs_iterator__seek(git_iterator *self, const char *prefix)
 {
 	GIT_UNUSED(self);
@@ -1037,11 +1062,8 @@ static int fs_iterator__reset(
 {
 	fs_iterator *fi = (fs_iterator *)self;
 
-	while (fi->stack != NULL && fi->stack->next != NULL) {
-		fs_iterator_frame *ff = fi->stack;
-		fi->stack = ff->next;
-		fs_iterator__free_frame(ff);
-	}
+	while (fi->stack != NULL && fi->stack->next != NULL)
+		fs_iterator__pop_frame(fi, fi->stack, false);
 	fi->depth = 0;
 
 	if (iterator__reset_range(self, start, end) < 0)
@@ -1056,11 +1078,8 @@ static void fs_iterator__free(git_iterator *self)
 {
 	fs_iterator *fi = (fs_iterator *)self;
 
-	while (fi->stack != NULL) {
-		fs_iterator_frame *ff = fi->stack;
-		fi->stack = ff->next;
-		fs_iterator__free_frame(ff);
-	}
+	while (fi->stack != NULL)
+		fs_iterator__pop_frame(fi, fi->stack, true);
 
 	git_buf_free(&fi->path);
 }
@@ -1075,10 +1094,8 @@ static int fs_iterator__update_entry(fs_iterator *fi)
 
 	if (!ps)
 		return 0;
-
 	if (git_buf_put(&fi->path, ps->path, ps->path_len) < 0)
 		return -1;
-
 	if (iterator__past_end(fi, fi->path.ptr + fi->root_len))
 		return 0;
 
@@ -1088,389 +1105,141 @@ static int fs_iterator__update_entry(fs_iterator *fi)
 	/* need different mode here to keep directories during iteration */
 	fi->entry.mode = git_futils_canonical_mode(ps->st.st_mode);
 
-	/* if this isn't a tree, then we're done */
-	if (fi->entry.mode != GIT_FILEMODE_TREE)
-		return 0;
+	/* allow wrapper to check/update the entry (can force skip) */
+	if (fi->entry_updated &&
+		fi->entry_updated(fi) == GIT_ENOTFOUND)
+		return fs_iterator__advance_over(NULL, (git_iterator *)fi);
 
-	if (iterator__include_trees(fi))
-		return 0;
+	/* if this is a tree and trees aren't included, then skip */
+	if (fi->entry.mode == GIT_FILEMODE_TREE && !iterator__include_trees(fi))
+		return git_iterator_advance(NULL, (git_iterator *)fi);
 
-	return fs_iterator__advance(NULL, (git_iterator *)fi);
+	return 0;
 }
 
-int git_iterator_for_filesystem(
-	git_iterator **out,
-	const char *root,
-	git_iterator_flag_t flags,
-	const char *start,
-	const char *end)
+static int fs_iterator__initialize(
+	git_iterator **out, fs_iterator *fi, const char *root)
 {
 	int error;
-	fs_iterator *fi;
-
-	ITERATOR_BASE_INIT(fi, fs, FS, NULL);
-
-	if ((flags & GIT_ITERATOR_IGNORE_CASE) != 0)
-		fi->base.flags |= GIT_ITERATOR_IGNORE_CASE;
 
 	if (git_buf_sets(&fi->path, root) < 0 || git_path_to_dir(&fi->path) < 0) {
 		git__free(fi);
 		return -1;
 	}
+
 	fi->root_len = fi->path.size;
 
-	if ((error = fs_iterator__expand_dir(fi)) < 0) {
-		if (error != GIT_ENOTFOUND)
-			goto fail;
+	if ((error = fs_iterator__expand_dir(fi)) == GIT_ENOTFOUND) {
 		giterr_clear();
+		error = 0;
+	}
+	if (error) {
+		git_iterator_free((git_iterator *)fi);
+		fi = NULL;
 	}
 
 	*out = (git_iterator *)fi;
-	return 0;
-
-fail:
-	git_iterator_free((git_iterator *)fi);
 	return error;
 }
 
+int git_iterator_for_filesystem(
+	git_iterator **out,
+	const char *root,
+	git_iterator_flag_t flags,
+	const char *start,
+	const char *end)
+{
+	fs_iterator *fi = git__calloc(1, sizeof(fs_iterator));
+	GITERR_CHECK_ALLOC(fi);
 
-#define WORKDIR_MAX_DEPTH 100
+	ITERATOR_BASE_INIT(fi, fs, FS, NULL);
+
+	if ((flags & GIT_ITERATOR_IGNORE_CASE) != 0)
+		fi->base.flags |= GIT_ITERATOR_IGNORE_CASE;
+
+	return fs_iterator__initialize(out, fi, root);
+}
 
-typedef struct workdir_iterator_frame workdir_iterator_frame;
-struct workdir_iterator_frame {
-	workdir_iterator_frame *next;
-	git_vector entries;
-	size_t index;
-};
 
 typedef struct {
-	git_iterator base;
-	git_iterator_callbacks cb;
-	workdir_iterator_frame *stack;
+	fs_iterator fi;
 	git_ignores ignores;
-	git_index_entry entry;
-	git_buf path;
-	size_t root_len;
 	int is_ignored;
-	int depth;
 } workdir_iterator;
 
-GIT_INLINE(bool) path_is_dotgit(const git_path_with_stat *ps)
+GIT_INLINE(bool) workdir_path_is_dotgit(const git_buf *path)
 {
-	if (!ps)
-		return false;
-	else {
-		const char *path = ps->path;
-		size_t len  = ps->path_len;
-
-		if (len < 4)
-			return false;
-		if (path[len - 1] == '/')
-			len--;
-		if (tolower(path[len - 1]) != 't' ||
-			tolower(path[len - 2]) != 'i' ||
-			tolower(path[len - 3]) != 'g' ||
-			tolower(path[len - 4]) != '.')
-			return false;
-		return (len == 4 || path[len - 5] == '/');
-	}
-}
-
-static workdir_iterator_frame *workdir_iterator__alloc_frame(
-	workdir_iterator *wi)
-{
-	workdir_iterator_frame *wf = git__calloc(1, sizeof(workdir_iterator_frame));
-	git_vector_cmp entry_compare = CASESELECT(
-		iterator__ignore_case(wi),
-		git_path_with_stat_cmp_icase, git_path_with_stat_cmp);
-
-	if (wf == NULL)
-		return NULL;
-
-	if (git_vector_init(&wf->entries, 0, entry_compare) != 0) {
-		git__free(wf);
-		return NULL;
-	}
-
-	return wf;
-}
-
-static void workdir_iterator__free_frame(workdir_iterator_frame *wf)
-{
-	unsigned int i;
-	git_path_with_stat *path;
-
-	git_vector_foreach(&wf->entries, i, path)
-		git__free(path);
-	git_vector_free(&wf->entries);
-	git__free(wf);
-}
+	size_t len;
 
-static int workdir_iterator__update_entry(workdir_iterator *wi);
-
-static int workdir_iterator__entry_cmp(const void *i, const void *item)
-{
-	const workdir_iterator *wi = (const workdir_iterator *)i;
-	const git_path_with_stat *ps = item;
-	return wi->base.prefixcomp(wi->base.start, ps->path);
-}
+	if (!path || (len = path->size) < 4)
+		return false;
 
-static void workdir_iterator__seek_frame_start(
-	workdir_iterator *wi, workdir_iterator_frame *wf)
-{
-	if (!wf)
-		return;
+	if (path->ptr[len - 1] == '/')
+		len--;
 
-	if (wi->base.start)
-		git_vector_bsearch2(
-			&wf->index, &wf->entries, workdir_iterator__entry_cmp, wi);
-	else
-		wf->index = 0;
+	if (tolower(path->ptr[len - 1]) != 't' ||
+		tolower(path->ptr[len - 2]) != 'i' ||
+		tolower(path->ptr[len - 3]) != 'g' ||
+		tolower(path->ptr[len - 4]) != '.')
+		return false;
 
-	if (path_is_dotgit(git_vector_get(&wf->entries, wf->index)))
-		wf->index++;
+	return (len == 4 || path->ptr[len - 5] == '/');
 }
 
-static int workdir_iterator__expand_dir(workdir_iterator *wi)
+static int workdir_iterator__frame_added(fs_iterator *fi)
 {
-	int error;
-	workdir_iterator_frame *wf;
-
-	wf = workdir_iterator__alloc_frame(wi);
-	GITERR_CHECK_ALLOC(wf);
-
-	error = git_path_dirload_with_stat(
-		wi->path.ptr, wi->root_len, iterator__ignore_case(wi),
-		wi->base.start, wi->base.end, &wf->entries);
-
-	if (error < 0 || wf->entries.length == 0) {
-		workdir_iterator__free_frame(wf);
-		return GIT_ENOTFOUND;
-	}
-
-	if (++(wi->depth) > WORKDIR_MAX_DEPTH) {
-		giterr_set(GITERR_REPOSITORY,
-			"Working directory is too deep (%d)", wi->depth);
-		workdir_iterator__free_frame(wf);
-		return -1;
-	}
-
-	workdir_iterator__seek_frame_start(wi, wf);
-
 	/* only push new ignores if this is not top level directory */
-	if (wi->stack != NULL) {
-		ssize_t slash_pos = git_buf_rfind_next(&wi->path, '/');
-		(void)git_ignore__push_dir(&wi->ignores, &wi->path.ptr[slash_pos + 1]);
-	}
-
-	wf->next  = wi->stack;
-	wi->stack = wf;
+	if (fi->stack->next != NULL) {
+		workdir_iterator *wi = (workdir_iterator *)fi;
+		ssize_t slash_pos = git_buf_rfind_next(&fi->path, '/');
 
-	return workdir_iterator__update_entry(wi);
-}
+		(void)git_ignore__push_dir(&wi->ignores, &fi->path.ptr[slash_pos + 1]);
+	}
 
-static int workdir_iterator__current(
-	const git_index_entry **entry, git_iterator *self)
-{
-	workdir_iterator *wi = (workdir_iterator *)self;
-	if (entry)
-		*entry = (wi->entry.path == NULL) ? NULL : &wi->entry;
 	return 0;
 }
 
-static int workdir_iterator__at_end(git_iterator *self)
+static int workdir_iterator__frame_removed(fs_iterator *fi)
 {
-	return (((workdir_iterator *)self)->entry.path == NULL);
+	workdir_iterator *wi = (workdir_iterator *)fi;
+	git_ignore__pop_dir(&wi->ignores);
+	return 0;
 }
 
-static int workdir_iterator__advance_into(
-	const git_index_entry **entry, git_iterator *iter)
+static int workdir_iterator__entry_updated(fs_iterator *fi)
 {
 	int error = 0;
-	workdir_iterator *wi = (workdir_iterator *)iter;
-
-	iterator__clear_entry(entry);
-
-	/* workdir iterator will allow you to explicitly advance into a
-	 * commit/submodule (as well as a tree) to avoid some cases where an
-	 * entry is mislabeled as a submodule in the working directory
-	 */
-	if (wi->entry.path != NULL &&
-		(wi->entry.mode == GIT_FILEMODE_TREE ||
-		 wi->entry.mode == GIT_FILEMODE_COMMIT))
-		/* returns GIT_ENOTFOUND if the directory is empty */
-		error = workdir_iterator__expand_dir(wi);
+	workdir_iterator *wi = (workdir_iterator *)fi;
 
-	if (!error && entry)
-		error = workdir_iterator__current(entry, iter);
-
-	return error;
-}
+	/* skip over .git entries */
+	if (workdir_path_is_dotgit(&fi->path))
+		return GIT_ENOTFOUND;
 
-static int workdir_iterator__advance(
-	const git_index_entry **entry, git_iterator *self)
-{
-	int error = 0;
-	workdir_iterator *wi = (workdir_iterator *)self;
-	workdir_iterator_frame *wf;
-	git_path_with_stat *next;
+	/* reset is_ignored since we haven't checked yet */
+	wi->is_ignored = -1;
 
-	/* given include_trees & autoexpand, we might have to go into a tree */
-	if (iterator__do_autoexpand(wi) &&
-		wi->entry.path != NULL &&
-		wi->entry.mode == GIT_FILEMODE_TREE)
-	{
-		error = workdir_iterator__advance_into(entry, self);
+	/* check if apparent tree entries are actually submodules */
+	if (fi->entry.mode != GIT_FILEMODE_TREE)
+		return 0;
 
-		/* continue silently past empty directories if autoexpanding */
-		if (error != GIT_ENOTFOUND)
-			return error;
+	error = git_submodule_lookup(NULL, fi->base.repo, fi->entry.path);
+	if (error < 0)
 		giterr_clear();
-		error = 0;
-	}
-
-	if (entry != NULL)
-		*entry = NULL;
 
-	while (wi->entry.path != NULL) {
-		wf   = wi->stack;
-		next = git_vector_get(&wf->entries, ++wf->index);
-
-		if (next != NULL) {
-			/* match git's behavior of ignoring anything named ".git" */
-			if (path_is_dotgit(next))
-				continue;
-			/* else found a good entry */
-			break;
-		}
-
-		/* pop stack if anything is left to pop */
-		if (!wf->next) {
-			memset(&wi->entry, 0, sizeof(wi->entry));
-			return 0;
-		}
-
-		wi->stack = wf->next;
-		wi->depth--;
-		workdir_iterator__free_frame(wf);
-		git_ignore__pop_dir(&wi->ignores);
+	/* mark submodule (or any dir with .git) as GITLINK and remove slash */
+	if (!error || error == GIT_EEXISTS) {
+		fi->entry.mode = S_IFGITLINK;
+		fi->entry.path[strlen(fi->entry.path) - 1] = '\0';
 	}
 
-	error = workdir_iterator__update_entry(wi);
-
-	if (!error && entry != NULL)
-		error = workdir_iterator__current(entry, self);
-
-	return error;
-}
-
-static int workdir_iterator__seek(git_iterator *self, const char *prefix)
-{
-	GIT_UNUSED(self);
-	GIT_UNUSED(prefix);
-	/* pop stack until matching prefix */
-	/* find prefix item in current frame */
-	/* push subdirectories as deep as possible while matching */
 	return 0;
 }
 
-static int workdir_iterator__reset(
-	git_iterator *self, const char *start, const char *end)
-{
-	workdir_iterator *wi = (workdir_iterator *)self;
-
-	while (wi->stack != NULL && wi->stack->next != NULL) {
-		workdir_iterator_frame *wf = wi->stack;
-		wi->stack = wf->next;
-		workdir_iterator__free_frame(wf);
-		git_ignore__pop_dir(&wi->ignores);
-	}
-	wi->depth = 0;
-
-	if (iterator__reset_range(self, start, end) < 0)
-		return -1;
-
-	workdir_iterator__seek_frame_start(wi, wi->stack);
-
-	return workdir_iterator__update_entry(wi);
-}
-
 static void workdir_iterator__free(git_iterator *self)
 {
 	workdir_iterator *wi = (workdir_iterator *)self;
-
-	while (wi->stack != NULL) {
-		workdir_iterator_frame *wf = wi->stack;
-		wi->stack = wf->next;
-		workdir_iterator__free_frame(wf);
-	}
-
+	fs_iterator__free(self);
 	git_ignore__free(&wi->ignores);
-	git_buf_free(&wi->path);
-}
-
-static int workdir_iterator__update_entry(workdir_iterator *wi)
-{
-	int error = 0;
-	git_path_with_stat *ps =
-		git_vector_get(&wi->stack->entries, wi->stack->index);
-
-	git_buf_truncate(&wi->path, wi->root_len);
-	memset(&wi->entry, 0, sizeof(wi->entry));
-
-	if (!ps)
-		return 0;
-
-	/* skip over .git entries */
-	if (path_is_dotgit(ps))
-		return workdir_iterator__advance(NULL, (git_iterator *)wi);
-
-	if (git_buf_put(&wi->path, ps->path, ps->path_len) < 0)
-		return -1;
-
-	if (iterator__past_end(wi, wi->path.ptr + wi->root_len))
-		return 0;
-
-	wi->entry.path = ps->path;
-
-	wi->is_ignored = -1;
-
-	git_index_entry__init_from_stat(&wi->entry, &ps->st);
-
-	/* need different mode here to keep directories during iteration */
-	wi->entry.mode = git_futils_canonical_mode(ps->st.st_mode);
-
-	/* if this is a file type we don't handle, treat as ignored */
-	if (wi->entry.mode == 0) {
-		wi->is_ignored = 1;
-		return 0;
-	}
-
-	/* if this isn't a tree, then we're done */
-	if (wi->entry.mode != GIT_FILEMODE_TREE)
-		return 0;
-
-	/* detect submodules */
-	error = git_submodule_lookup(NULL, wi->base.repo, wi->entry.path);
-	if (error == GIT_ENOTFOUND)
-		giterr_clear();
-
-	if (error == GIT_EEXISTS) /* if contains .git, treat as untracked submod */
-		error = 0;
-
-	/* if submodule, mark as GITLINK and remove trailing slash */
-	if (!error) {
-		size_t len = strlen(wi->entry.path);
-		assert(wi->entry.path[len - 1] == '/');
-		wi->entry.path[len - 1] = '\0';
-		wi->entry.mode = S_IFGITLINK;
-		return 0;
-	}
-
-	if (iterator__include_trees(wi))
-		return 0;
-
-	return workdir_iterator__advance(NULL, (git_iterator *)wi);
 }
 
 int git_iterator_for_workdir(
@@ -1481,7 +1250,8 @@ int git_iterator_for_workdir(
 	const char *end)
 {
 	int error;
-	workdir_iterator *wi;
+	workdir_iterator *wi = git__calloc(1, sizeof(workdir_iterator));
+	GITERR_CHECK_ALLOC(wi);
 
 	assert(iter && repo);
 
@@ -1489,32 +1259,24 @@ int git_iterator_for_workdir(
 			 repo, "scan working directory")) < 0)
 		return error;
 
-	ITERATOR_BASE_INIT(wi, workdir, WORKDIR, repo);
+	/* initialize as an fs iterator then do overrides */
+	ITERATOR_BASE_INIT((&wi->fi), fs, FS, repo);
 
-	if ((error = iterator__update_ignore_case((git_iterator *)wi, flags)) < 0)
-		goto fail;
+	wi->fi.base.type     = GIT_ITERATOR_TYPE_WORKDIR;
+	wi->fi.cb.free       = workdir_iterator__free;
+	wi->fi.frame_added   = workdir_iterator__frame_added;
+	wi->fi.frame_removed = workdir_iterator__frame_removed;
+	wi->fi.entry_updated = workdir_iterator__entry_updated;
 
-	if (git_buf_sets(&wi->path, git_repository_workdir(repo)) < 0 ||
-		git_path_to_dir(&wi->path) < 0 ||
-		git_ignore__for_path(repo, "", &wi->ignores) < 0)
+	if ((error = iterator__update_ignore_case((git_iterator *)wi, flags)) < 0 ||
+		(error = git_ignore__for_path(repo, "", &wi->ignores)) < 0)
 	{
-		git__free(wi);
-		return -1;
-	}
-	wi->root_len = wi->path.size;
-
-	if ((error = workdir_iterator__expand_dir(wi)) < 0) {
-		if (error != GIT_ENOTFOUND)
-			goto fail;
-		giterr_clear();
+		git_iterator_free((git_iterator *)wi);
+		return error;
 	}
 
-	*iter = (git_iterator *)wi;
-	return 0;
-
-fail:
-	git_iterator_free((git_iterator *)wi);
-	return error;
+	return fs_iterator__initialize(
+		iter, (fs_iterator *)wi, git_repository_workdir(repo));
 }
 
 
@@ -1616,7 +1378,8 @@ bool git_iterator_current_is_ignored(git_iterator *iter)
 	if (wi->is_ignored != -1)
 		return (bool)(wi->is_ignored != 0);
 
-	if (git_ignore__lookup(&wi->ignores, wi->entry.path, &wi->is_ignored) < 0)
+	if (git_ignore__lookup(
+			&wi->ignores, wi->fi.entry.path, &wi->is_ignored) < 0)
 		wi->is_ignored = true;
 
 	return (bool)wi->is_ignored;
@@ -1641,10 +1404,10 @@ int git_iterator_current_workdir_path(git_buf **path, git_iterator *iter)
 {
 	workdir_iterator *wi = (workdir_iterator *)iter;
 
-	if (iter->type != GIT_ITERATOR_TYPE_WORKDIR || !wi->entry.path)
+	if (iter->type != GIT_ITERATOR_TYPE_WORKDIR || !wi->fi.entry.path)
 		*path = NULL;
 	else
-		*path = &wi->path;
+		*path = &wi->fi.path;
 
 	return 0;
 }