Merge pull request #1016 from arrbee/fix-checkout-dir-removal

Update checkout with new strategies & behavior

24 files changed, 1166 insertions, 525 deletions

diff --git a/src/attr_file.h b/src/attr_file.h
index 3ea13d273..5bdfc7054 100644
--- a/src/attr_file.h
+++ b/src/attr_file.h
@@ -7,6 +7,7 @@
 #ifndef INCLUDE_attr_file_h__
 #define INCLUDE_attr_file_h__
 
+#include "git2/oid.h"
 #include "git2/attr.h"
 #include "vector.h"
 #include "pool.h"
diff --git a/src/checkout.c b/src/checkout.c
index e068e4f5f..0d14e2625 100644
--- a/src/checkout.c
+++ b/src/checkout.c
@@ -21,20 +21,20 @@
 #include "repository.h"
 #include "filter.h"
 #include "blob.h"
+#include "diff.h"
+#include "pathspec.h"
 
-struct checkout_diff_data
-{
+typedef struct {
+	git_repository *repo;
+	git_diff_list *diff;
+	git_checkout_opts *opts;
 	git_buf *path;
 	size_t workdir_len;
-	git_checkout_opts *checkout_opts;
-	git_repository *owner;
 	bool can_symlink;
-	bool found_submodules;
-	bool create_submodules;
 	int error;
 	size_t total_steps;
 	size_t completed_steps;
-};
+} checkout_diff_data;
 
 static int buffer_to_file(
 	git_buf *buffer,
@@ -43,20 +43,23 @@ static int buffer_to_file(
 	int file_open_flags,
 	mode_t file_mode)
 {
-	int fd, error, error_close;
+	int fd, error;
 
 	if ((error = git_futils_mkpath2file(path, dir_mode)) < 0)
 		return error;
 
-	if ((fd = p_open(path, file_open_flags, file_mode)) < 0)
+	if ((fd = p_open(path, file_open_flags, file_mode)) < 0) {
+		giterr_set(GITERR_OS, "Could not open '%s' for writing", path);
 		return fd;
+	}
 
-	error = p_write(fd, git_buf_cstr(buffer), git_buf_len(buffer));
-
-	error_close = p_close(fd);
-
-	if (!error)
-		error = error_close;
+	if ((error = p_write(fd, git_buf_cstr(buffer), git_buf_len(buffer))) < 0) {
+		giterr_set(GITERR_OS, "Could not write to '%s'", path);
+		(void)p_close(fd);
+	} else {
+		if ((error = p_close(fd)) < 0)
+			giterr_set(GITERR_OS, "Error while closing '%s'", path);
+	}
 
 	if (!error &&
 		(file_mode & 0100) != 0 &&
@@ -108,7 +111,8 @@ static int blob_content_to_file(
 	if (!file_mode)
 		file_mode = entry_filemode;
 
-	error = buffer_to_file(&filtered, path, opts->dir_mode, opts->file_open_flags, file_mode);
+	error = buffer_to_file(
+		&filtered, path, opts->dir_mode, opts->file_open_flags, file_mode);
 
 cleanup:
 	git_filters_free(&filters);
@@ -119,7 +123,8 @@ cleanup:
 	return error;
 }
 
-static int blob_content_to_link(git_blob *blob, const char *path, bool can_symlink)
+static int blob_content_to_link(
+	git_blob *blob, const char *path, bool can_symlink)
 {
 	git_buf linktarget = GIT_BUF_INIT;
 	int error;
@@ -138,51 +143,52 @@ static int blob_content_to_link(git_blob *blob, const char *path, bool can_symli
 }
 
 static int checkout_submodule(
-	struct checkout_diff_data *data,
+	checkout_diff_data *data,
 	const git_diff_file *file)
 {
+	/* Until submodules are supported, UPDATE_ONLY means do nothing here */
+	if ((data->opts->checkout_strategy & GIT_CHECKOUT_UPDATE_ONLY) != 0)
+		return 0;
+
 	if (git_futils_mkdir(
-			file->path, git_repository_workdir(data->owner),
-			data->checkout_opts->dir_mode, GIT_MKDIR_PATH) < 0)
+			file->path, git_repository_workdir(data->repo),
+			data->opts->dir_mode, GIT_MKDIR_PATH) < 0)
 		return -1;
 
-	/* TODO: two cases:
+	/* TODO: Support checkout_strategy options.  Two circumstances:
 	 * 1 - submodule already checked out, but we need to move the HEAD
 	 *     to the new OID, or
 	 * 2 - submodule not checked out and we should recursively check it out
 	 *
-	 * Checkout will not execute a pull request on the submodule, but a
-	 * clone command should probably be able to.  Do we need a submodule
-	 * callback option?
+	 * Checkout will not execute a pull on the submodule, but a clone
+	 * command should probably be able to.  Do we need a submodule callback?
 	 */
 
 	return 0;
 }
 
 static void report_progress(
-		struct checkout_diff_data *data,
-		const char *path)
+	checkout_diff_data *data,
+	const char *path)
 {
-	if (data->checkout_opts->progress_cb)
-		data->checkout_opts->progress_cb(
-				path,
-				data->completed_steps,
-				data->total_steps,
-				data->checkout_opts->progress_payload);
+	if (data->opts->progress_cb)
+		data->opts->progress_cb(
+			path, data->completed_steps, data->total_steps,
+			data->opts->progress_payload);
 }
 
 static int checkout_blob(
-	struct checkout_diff_data *data,
+	checkout_diff_data *data,
 	const git_diff_file *file)
 {
+	int error = 0;
 	git_blob *blob;
-	int error;
 
 	git_buf_truncate(data->path, data->workdir_len);
-	if (git_buf_joinpath(data->path, git_buf_cstr(data->path), file->path) < 0)
+	if (git_buf_puts(data->path, file->path) < 0)
 		return -1;
 
-	if ((error = git_blob_lookup(&blob, data->owner, &file->oid)) < 0)
+	if ((error = git_blob_lookup(&blob, data->repo, &file->oid)) < 0)
 		return error;
 
 	if (S_ISLNK(file->mode))
@@ -190,138 +196,407 @@ static int checkout_blob(
 			blob, git_buf_cstr(data->path), data->can_symlink);
 	else
 		error = blob_content_to_file(
-			blob, git_buf_cstr(data->path), file->mode, data->checkout_opts);
+			blob, git_buf_cstr(data->path), file->mode, data->opts);
 
 	git_blob_free(blob);
 
 	return error;
 }
 
-static int checkout_remove_the_old(
-	void *cb_data, const git_diff_delta *delta, float progress)
+static int retrieve_symlink_caps(git_repository *repo, bool *can_symlink)
 {
-	struct checkout_diff_data *data = cb_data;
-	git_checkout_opts *opts = data->checkout_opts;
+	git_config *cfg;
+	int error;
 
-	GIT_UNUSED(progress);
+	if (git_repository_config__weakptr(&cfg, repo) < 0)
+		return -1;
 
-	if ((delta->status == GIT_DELTA_UNTRACKED &&
-		 (opts->checkout_strategy & GIT_CHECKOUT_REMOVE_UNTRACKED) != 0) ||
-		(delta->status == GIT_DELTA_TYPECHANGE &&
-		 (opts->checkout_strategy & GIT_CHECKOUT_OVERWRITE_MODIFIED) != 0))
-	{
-		data->error = git_futils_rmdir_r(
-			delta->new_file.path,
-			git_repository_workdir(data->owner),
-			GIT_DIRREMOVAL_FILES_AND_DIRS);
+	error = git_config_get_bool((int *)can_symlink, cfg, "core.symlinks");
 
-		data->completed_steps++;
-		report_progress(data, delta->new_file.path);
+	/* If "core.symlinks" is not found anywhere, default to true. */
+	if (error == GIT_ENOTFOUND) {
+		*can_symlink = true;
+		error = 0;
 	}
 
-	return data->error;
+	return error;
 }
 
-static int checkout_create_the_new(
-	void *cb_data, const git_diff_delta *delta, float progress)
+static void normalize_options(
+	git_checkout_opts *normalized, git_checkout_opts *proposed)
 {
-	int error = 0;
-	struct checkout_diff_data *data = cb_data;
-	git_checkout_opts *opts = data->checkout_opts;
-	bool do_checkout = false, do_notify = false;
+	assert(normalized);
 
-	GIT_UNUSED(progress);
+	if (!proposed)
+		memset(normalized, 0, sizeof(git_checkout_opts));
+	else
+		memmove(normalized, proposed, sizeof(git_checkout_opts));
 
-	if (delta->status == GIT_DELTA_MODIFIED ||
-		delta->status == GIT_DELTA_TYPECHANGE)
-	{
-		if ((opts->checkout_strategy & GIT_CHECKOUT_OVERWRITE_MODIFIED) != 0)
-			do_checkout = true;
-		else if (opts->skipped_notify_cb != NULL)
-			do_notify = !data->create_submodules;
+	/* implied checkout strategies */
+	if ((normalized->checkout_strategy & GIT_CHECKOUT_UPDATE_MODIFIED) != 0 ||
+		(normalized->checkout_strategy & GIT_CHECKOUT_UPDATE_UNTRACKED) != 0)
+		normalized->checkout_strategy |= GIT_CHECKOUT_UPDATE_UNMODIFIED;
+
+	if ((normalized->checkout_strategy & GIT_CHECKOUT_UPDATE_UNTRACKED) != 0)
+		normalized->checkout_strategy |= GIT_CHECKOUT_UPDATE_MISSING;
+
+	/* opts->disable_filters is false by default */
+
+	if (!normalized->dir_mode)
+		normalized->dir_mode = GIT_DIR_MODE;
+
+	if (!normalized->file_open_flags)
+		normalized->file_open_flags = O_CREAT | O_TRUNC | O_WRONLY;
+}
+
+enum {
+	CHECKOUT_ACTION__NONE = 0,
+	CHECKOUT_ACTION__REMOVE = 1,
+	CHECKOUT_ACTION__UPDATE_BLOB = 2,
+	CHECKOUT_ACTION__UPDATE_SUBMODULE = 4,
+	CHECKOUT_ACTION__CONFLICT = 8,
+	CHECKOUT_ACTION__MAX = 8
+};
+
+static int checkout_confirm_update_blob(
+	checkout_diff_data *data,
+	const git_diff_delta *delta,
+	int action)
+{
+	int error;
+	unsigned int strat = data->opts->checkout_strategy;
+	struct stat st;
+	bool update_only = ((strat & GIT_CHECKOUT_UPDATE_ONLY) != 0);
+
+	/* for typechange, remove the old item first */
+	if (delta->status == GIT_DELTA_TYPECHANGE) {
+		if (update_only)
+			action = CHECKOUT_ACTION__NONE;
+		else
+			action |= CHECKOUT_ACTION__REMOVE;
+
+		return action;
 	}
-	else if (delta->status == GIT_DELTA_DELETED &&
-			 (opts->checkout_strategy & GIT_CHECKOUT_CREATE_MISSING) != 0)
-		do_checkout = true;
 
-	if (do_notify) {
-		if (opts->skipped_notify_cb(
-			delta->old_file.path, &delta->old_file.oid,
-			delta->old_file.mode, opts->notify_payload))
-		{
-			giterr_clear();
-			error = GIT_EUSER;
+	git_buf_truncate(data->path, data->workdir_len);
+	if (git_buf_puts(data->path, delta->new_file.path) < 0)
+		return -1;
+
+	if ((error = p_stat(git_buf_cstr(data->path), &st)) < 0) {
+		if (errno == ENOENT) {
+			if (update_only)
+				action = CHECKOUT_ACTION__NONE;
+		} else if (errno == ENOTDIR) {
+			/* File exists where a parent dir needs to go - i.e. untracked
+			 * typechange.  Ignore if UPDATE_ONLY, remove if allowed.
+			 */
+			if (update_only)
+				action = CHECKOUT_ACTION__NONE;
+			else if ((strat & GIT_CHECKOUT_UPDATE_UNTRACKED) != 0)
+				action |= CHECKOUT_ACTION__REMOVE;
+			else
+				action = CHECKOUT_ACTION__CONFLICT;
 		}
+		/* otherwise let error happen when we attempt blob checkout later */
+	}
+	else if (S_ISDIR(st.st_mode)) {
+		/* Directory exists where a blob needs to go - i.e. untracked
+		 * typechange.  Ignore if UPDATE_ONLY, remove if allowed.
+		 */
+		if (update_only)
+			action = CHECKOUT_ACTION__NONE;
+		else if ((strat & GIT_CHECKOUT_UPDATE_UNTRACKED) != 0)
+			action |= CHECKOUT_ACTION__REMOVE;
+		else
+			action = CHECKOUT_ACTION__CONFLICT;
 	}
 
-	if (do_checkout) {
-		bool is_submodule = S_ISGITLINK(delta->old_file.mode);
+	return action;
+}
 
-		if (is_submodule) {
-			data->found_submodules = true;
+static int checkout_action_for_delta(
+	checkout_diff_data *data,
+	const git_diff_delta *delta,
+	const git_index_entry *head_entry)
+{
+	int action = CHECKOUT_ACTION__NONE;
+	unsigned int strat  = data->opts->checkout_strategy;
+
+	switch (delta->status) {
+	case GIT_DELTA_UNMODIFIED:
+		if (!head_entry) {
+			/* file independently created in wd, even though not in HEAD */
+			if ((strat & GIT_CHECKOUT_UPDATE_MISSING) == 0)
+				action = CHECKOUT_ACTION__CONFLICT;
+		}
+		else if (!git_oid_equal(&head_entry->oid, &delta->old_file.oid)) {
+			/* working directory was independently updated to match index */
+			if ((strat & GIT_CHECKOUT_UPDATE_MODIFIED) == 0)
+				action = CHECKOUT_ACTION__CONFLICT;
+		}
+		break;
+
+	case GIT_DELTA_ADDED:
+		/* Impossible.  New files should be UNTRACKED or TYPECHANGE */
+		action = CHECKOUT_ACTION__CONFLICT;
+		break;
+
+	case GIT_DELTA_DELETED:
+		if (head_entry && /* working dir missing, but exists in HEAD */
+			(strat & GIT_CHECKOUT_UPDATE_MISSING) == 0)
+			action = CHECKOUT_ACTION__CONFLICT;
+		else
+			action = CHECKOUT_ACTION__UPDATE_BLOB;
+		break;
+
+	case GIT_DELTA_MODIFIED:
+	case GIT_DELTA_TYPECHANGE:
+		if (!head_entry) {
+			/* working dir was independently updated & does not match index */
+			if ((strat & GIT_CHECKOUT_UPDATE_UNTRACKED) == 0)
+				action = CHECKOUT_ACTION__CONFLICT;
+			else
+				action = CHECKOUT_ACTION__UPDATE_BLOB;
+		}
+		else if (git_oid_equal(&head_entry->oid, &delta->new_file.oid))
+			action = CHECKOUT_ACTION__UPDATE_BLOB;
+		else if ((strat & GIT_CHECKOUT_UPDATE_MODIFIED) == 0)
+			action = CHECKOUT_ACTION__CONFLICT;
+		else
+			action = CHECKOUT_ACTION__UPDATE_BLOB;
+		break;
+
+	case GIT_DELTA_UNTRACKED:
+		if (!head_entry) {
+			if ((strat & GIT_CHECKOUT_REMOVE_UNTRACKED) != 0)
+				action = CHECKOUT_ACTION__REMOVE;
 		}
+		else if ((strat & GIT_CHECKOUT_UPDATE_MODIFIED) != 0) {
+			action = CHECKOUT_ACTION__REMOVE;
+		} else if ((strat & GIT_CHECKOUT_UPDATE_UNMODIFIED) != 0) {
+			git_oid wd_oid;
+
+			/* if HEAD matches workdir, then remove, else conflict */
+
+			if (git_oid_iszero(&delta->new_file.oid) &&
+				git_diff__oid_for_file(
+					data->repo, delta->new_file.path, delta->new_file.mode,
+					delta->new_file.size, &wd_oid) < 0)
+				action = -1;
+			else if (git_oid_equal(&head_entry->oid, &wd_oid))
+				action = CHECKOUT_ACTION__REMOVE;
+			else
+				action = CHECKOUT_ACTION__CONFLICT;
+		} else {
+			/* present in HEAD and workdir, but absent in index */
+			action = CHECKOUT_ACTION__CONFLICT;
+		}
+		break;
 
-		if (!is_submodule && !data->create_submodules) {
-			error = checkout_blob(data, &delta->old_file);
-			data->completed_steps++;
-			report_progress(data, delta->old_file.path);
+	case GIT_DELTA_IGNORED:
+	default:
+		/* just skip these files */
+		break;
+	}
+
+	if (action > 0 && (action & CHECKOUT_ACTION__UPDATE_BLOB) != 0) {
+		if (S_ISGITLINK(delta->old_file.mode))
+			action = (action & ~CHECKOUT_ACTION__UPDATE_BLOB) |
+				CHECKOUT_ACTION__UPDATE_SUBMODULE;
+
+		action = checkout_confirm_update_blob(data, delta, action);
+	}
+
+	if (action == CHECKOUT_ACTION__CONFLICT &&
+		data->opts->conflict_cb != NULL &&
+		data->opts->conflict_cb(
+			delta->old_file.path, &delta->old_file.oid,
+			delta->old_file.mode, delta->new_file.mode,
+			data->opts->conflict_payload) != 0)
+	{
+		giterr_clear();
+		action = GIT_EUSER;
+	}
+
+	if (action > 0 && (strat & GIT_CHECKOUT_UPDATE_ONLY) != 0)
+		action = (action & ~CHECKOUT_ACTION__REMOVE);
+
+	return action;
+}
+
+static int checkout_get_actions(
+	uint32_t **actions_ptr,
+	size_t **counts_ptr,
+	checkout_diff_data *data)
+{
+	int error;
+	git_diff_list *diff = data->diff;
+	git_diff_delta *delta;
+	size_t i, *counts = NULL;
+	uint32_t *actions = NULL;
+	git_tree *head = NULL;
+	git_iterator *hiter = NULL;
+	char *pfx = git_pathspec_prefix(&data->opts->paths);
+	const git_index_entry *he;
+
+	/* if there is no HEAD, that's okay - we'll make an empty iterator */
+	(void)git_repository_head_tree(&head, data->repo);
+
+	if ((error = git_iterator_for_tree_range(
+			 &hiter, data->repo, head, pfx, pfx)) < 0)
+		goto fail;
+
+	if ((diff->opts.flags & GIT_DIFF_DELTAS_ARE_ICASE) != 0 &&
+		!hiter->ignore_case &&
+		(error = git_iterator_spoolandsort(
+			&hiter, hiter, diff->entrycomp, true)) < 0)
+		goto fail;
+
+	if ((error = git_iterator_current(hiter, &he)) < 0)
+		goto fail;
+
+	git__free(pfx);
+	pfx = NULL;
+
+	*counts_ptr = counts = git__calloc(CHECKOUT_ACTION__MAX+1, sizeof(size_t));
+	*actions_ptr = actions = git__calloc(diff->deltas.length, sizeof(uint32_t));
+	if (!counts || !actions) {
+		error = -1;
+		goto fail;
+	}
+
+	git_vector_foreach(&diff->deltas, i, delta) {
+		int cmp = -1, act;
+
+		/* try to track HEAD entries parallel to deltas */
+		while (he) {
+			cmp = S_ISDIR(delta->new_file.mode) ?
+				diff->pfxcomp(he->path, delta->new_file.path) :
+				diff->strcomp(he->path, delta->old_file.path);
+			if (cmp >= 0)
+				break;
+			if (git_iterator_advance(hiter, &he) < 0)
+				he = NULL;
 		}
 
-		else if (is_submodule && data->create_submodules) {
-			error = checkout_submodule(data, &delta->old_file);
-			data->completed_steps++;
-			report_progress(data, delta->old_file.path);
+		act = checkout_action_for_delta(data, delta, !cmp ? he : NULL);
+
+		if (act < 0) {
+			error = act;
+			goto fail;
 		}
 
+		if (!cmp && git_iterator_advance(hiter, &he) < 0)
+			he = NULL;
+
+		actions[i] = act;
+
+		if (act & CHECKOUT_ACTION__REMOVE)
+			counts[CHECKOUT_ACTION__REMOVE]++;
+		if (act & CHECKOUT_ACTION__UPDATE_BLOB)
+			counts[CHECKOUT_ACTION__UPDATE_BLOB]++;
+		if (act & CHECKOUT_ACTION__UPDATE_SUBMODULE)
+			counts[CHECKOUT_ACTION__UPDATE_SUBMODULE]++;
+		if (act & CHECKOUT_ACTION__CONFLICT)
+			counts[CHECKOUT_ACTION__CONFLICT]++;
+	}
+
+	if (counts[CHECKOUT_ACTION__CONFLICT] > 0 &&
+		(data->opts->checkout_strategy & GIT_CHECKOUT_ALLOW_CONFLICTS) == 0)
+	{
+		giterr_set(GITERR_CHECKOUT, "%d conflicts prevent checkout",
+				   (int)counts[CHECKOUT_ACTION__CONFLICT]);
+		goto fail;
 	}
 
-	if (error)
-		data->error = error;
+	git_iterator_free(hiter);
+	git_tree_free(head);
 
-	return error;
+	return 0;
+
+fail:
+	*counts_ptr = NULL;
+	git__free(counts);
+	*actions_ptr = NULL;
+	git__free(actions);
+
+	git_iterator_free(hiter);
+	git_tree_free(head);
+	git__free(pfx);
+
+	return -1;
 }
 
-static int retrieve_symlink_capabilities(git_repository *repo, bool *can_symlink)
+static int checkout_remove_the_old(
+	git_diff_list *diff,
+	unsigned int *actions,
+	checkout_diff_data *data)
 {
-	git_config *cfg;
-	int error;
+	git_diff_delta *delta;
+	size_t i;
 
-	if (git_repository_config__weakptr(&cfg, repo) < 0)
-		return -1;
+	git_buf_truncate(data->path, data->workdir_len);
 
-	error = git_config_get_bool((int *)can_symlink, cfg, "core.symlinks");
+	git_vector_foreach(&diff->deltas, i, delta) {
+		if (actions[i] & CHECKOUT_ACTION__REMOVE) {
+			int error = git_futils_rmdir_r(
+				delta->new_file.path,
+				git_buf_cstr(data->path), /* here set to work dir root */
+				GIT_RMDIR_REMOVE_FILES | GIT_RMDIR_EMPTY_PARENTS |
+				GIT_RMDIR_REMOVE_BLOCKERS);
+			if (error < 0)
+				return error;
 
-	/*
-	 * When no "core.symlinks" entry is found in any of the configuration
-	 * store (local, global or system), default value is "true".
-	 */
-	if (error == GIT_ENOTFOUND) {
-		*can_symlink = true;
-		error = 0;
+			data->completed_steps++;
+			report_progress(data, delta->new_file.path);
+		}
 	}
 
-	return error;
+	return 0;
 }
 
-static void normalize_options(git_checkout_opts *normalized, git_checkout_opts *proposed)
+static int checkout_create_the_new(
+	git_diff_list *diff,
+	unsigned int *actions,
+	checkout_diff_data *data)
 {
-	assert(normalized);
+	git_diff_delta *delta;
+	size_t i;
 
-	if (!proposed)
-		memset(normalized, 0, sizeof(git_checkout_opts));
-	else
-		memmove(normalized, proposed, sizeof(git_checkout_opts));
+	git_vector_foreach(&diff->deltas, i, delta) {
+		if (actions[i] & CHECKOUT_ACTION__UPDATE_BLOB) {
+			int error = checkout_blob(data, &delta->old_file);
+			if (error < 0)
+				return error;
 
-	/* Default options */
-	if (!normalized->checkout_strategy)
-		normalized->checkout_strategy = GIT_CHECKOUT_DEFAULT;
+			data->completed_steps++;
+			report_progress(data, delta->old_file.path);
+		}
+	}
 
-	/* opts->disable_filters is false by default */
-	if (!normalized->dir_mode)
-		normalized->dir_mode = GIT_DIR_MODE;
+	return 0;
+}
 
-	if (!normalized->file_open_flags)
-		normalized->file_open_flags = O_CREAT | O_TRUNC | O_WRONLY;
+static int checkout_create_submodules(
+	git_diff_list *diff,
+	unsigned int *actions,
+	checkout_diff_data *data)
+{
+	git_diff_delta *delta;
+	size_t i;
+
+	git_vector_foreach(&diff->deltas, i, delta) {
+		if (actions[i] & CHECKOUT_ACTION__UPDATE_SUBMODULE) {
+			int error = checkout_submodule(data, &delta->old_file);
+			if (error < 0)
+				return error;
+
+			data->completed_steps++;
+			report_progress(data, delta->old_file.path);
+		}
+	}
+
+	return 0;
 }
 
 int git_checkout_index(
@@ -329,13 +604,13 @@ int git_checkout_index(
 	git_checkout_opts *opts)
 {
 	git_diff_list *diff = NULL;
-
 	git_diff_options diff_opts = {0};
 	git_checkout_opts checkout_opts;
 
-	struct checkout_diff_data data;
+	checkout_diff_data data;
 	git_buf workdir = GIT_BUF_INIT;
-
+	uint32_t *actions = NULL;
+	size_t *counts = NULL;
 	int error;
 
 	assert(repo);
@@ -344,9 +619,8 @@ int git_checkout_index(
 		return error;
 
 	diff_opts.flags =
-		GIT_DIFF_INCLUDE_UNTRACKED |
-		GIT_DIFF_INCLUDE_TYPECHANGE |
-		GIT_DIFF_SKIP_BINARY_CHECK;
+		GIT_DIFF_INCLUDE_UNMODIFIED | GIT_DIFF_INCLUDE_UNTRACKED |
+		GIT_DIFF_INCLUDE_TYPECHANGE | GIT_DIFF_SKIP_BINARY_CHECK;
 
 	if (opts && opts->paths.count > 0)
 		diff_opts.pathspec = opts->paths;
@@ -359,20 +633,10 @@ int git_checkout_index(
 
 	normalize_options(&checkout_opts, opts);
 
-	memset(&data, 0, sizeof(data));
-
-	data.path = &workdir;
-	data.workdir_len = git_buf_len(&workdir);
-	data.checkout_opts = &checkout_opts;
-	data.owner = repo;
-	data.total_steps = (size_t)git_diff_num_deltas(diff);
-
-	if ((error = retrieve_symlink_capabilities(repo, &data.can_symlink)) < 0)
-		goto cleanup;
-
-	/* Checkout is best performed with three passes through the diff.
+	/* Checkout is best performed with up to four passes through the diff.
 	 *
-	 * 1. First do removes, because we iterate in alphabetical order, thus
+	 * 0. Figure out what actions should be taken and record for later.
+	 * 1. Next do removes, because we iterate in alphabetical order, thus
 	 *    a new untracked directory will end up sorted *after* a blob that
 	 *    should be checked out with the same name.
 	 * 2. Then checkout all blobs.
@@ -380,23 +644,45 @@ int git_checkout_index(
 	 *    checked out during pass #2.
 	 */
 
-	report_progress(&data, NULL);
+	memset(&data, 0, sizeof(data));
+	data.path = &workdir;
+	data.workdir_len = git_buf_len(&workdir);
+	data.repo = repo;
+	data.diff = diff;
+	data.opts = &checkout_opts;
 
-	if (!(error = git_diff_foreach(
-			diff, &data, checkout_remove_the_old, NULL, NULL)) &&
-		!(error = git_diff_foreach(
-			diff, &data, checkout_create_the_new, NULL, NULL)) &&
-		data.found_submodules)
-	{
-		data.create_submodules = true;
-		error = git_diff_foreach(
-			diff, &data, checkout_create_the_new, NULL, NULL);
-	}
+	if ((error = checkout_get_actions(&actions, &counts, &data)) < 0)
+		goto cleanup;
+
+	data.total_steps = counts[CHECKOUT_ACTION__REMOVE] +
+		counts[CHECKOUT_ACTION__UPDATE_BLOB] +
+		counts[CHECKOUT_ACTION__UPDATE_SUBMODULE];
+
+	if ((error = retrieve_symlink_caps(repo, &data.can_symlink)) < 0)
+		goto cleanup;
+
+	report_progress(&data, NULL); /* establish 0 baseline */
+
+	if (counts[CHECKOUT_ACTION__REMOVE] > 0 &&
+		(error = checkout_remove_the_old(diff, actions, &data)) < 0)
+		goto cleanup;
+
+	if (counts[CHECKOUT_ACTION__UPDATE_BLOB] > 0 &&
+		(error = checkout_create_the_new(diff, actions, &data)) < 0)
+		goto cleanup;
+
+	if (counts[CHECKOUT_ACTION__UPDATE_SUBMODULE] > 0 &&
+		(error = checkout_create_submodules(diff, actions, &data)) < 0)
+		goto cleanup;
+
+	assert(data.completed_steps == data.total_steps);
 
 cleanup:
 	if (error == GIT_EUSER)
-		error = (data.error != 0) ? data.error : -1;
+		giterr_clear();
 
+	git__free(actions);
+	git__free(counts);
 	git_diff_list_free(diff);
 	git_buf_free(&workdir);
 
@@ -408,32 +694,28 @@ int git_checkout_tree(
 	git_object *treeish,
 	git_checkout_opts *opts)
 {
+	int error = 0;
 	git_index *index = NULL;
 	git_tree *tree = NULL;
 
-	int error;
-
 	assert(repo && treeish);
 
 	if (git_object_peel((git_object **)&tree, treeish, GIT_OBJ_TREE) < 0) {
-		giterr_set(GITERR_INVALID, "Provided treeish cannot be peeled into a tree.");
-		return GIT_ERROR;
+		giterr_set(
+			GITERR_CHECKOUT, "Provided object cannot be peeled to a tree");
+		return -1;
 	}
 
-	if ((error = git_repository_index(&index, repo)) < 0)
-		goto cleanup;
+	/* load paths in tree that match pathspec into index */
+	if (!(error = git_repository_index(&index, repo)) &&
+		!(error = git_index_read_tree_match(
+			index, tree, opts ? &opts->paths : NULL)) &&
+		!(error = git_index_write(index)))
+		error = git_checkout_index(repo, opts);
 
-	if ((error = git_index_read_tree(index, tree)) < 0)
-		goto cleanup;
-
-	if ((error = git_index_write(index)) < 0)
-		goto cleanup;
-
-	error = git_checkout_index(repo, opts);
-
-cleanup:
 	git_index_free(index);
 	git_tree_free(tree);
+
 	return error;
 }
 
@@ -441,21 +723,16 @@ int git_checkout_head(
 	git_repository *repo,
 	git_checkout_opts *opts)
 {
-	git_reference *head;
 	int error;
+	git_reference *head = NULL;
 	git_object *tree = NULL;
 
 	assert(repo);
 
-	if ((error = git_repository_head(&head, repo)) < 0)
-		return error;
-	
-	if ((error = git_reference_peel(&tree, head, GIT_OBJ_TREE)) < 0)
-		goto cleanup;
+	if (!(error = git_repository_head(&head, repo)) &&
+		!(error = git_reference_peel(&tree, head, GIT_OBJ_TREE)))
+		error = git_checkout_tree(repo, tree, opts);
 
-	error = git_checkout_tree(repo, tree, opts);
-
-cleanup:
 	git_reference_free(head);
 	git_object_free(tree);
 
diff --git a/src/clone.c b/src/clone.c
index d75fee213..9ef6f8100 100644
--- a/src/clone.c
+++ b/src/clone.c
@@ -344,7 +344,7 @@ static int clone_internal(
 						fetch_progress_cb, fetch_progress_payload)) < 0) {
 			/* Failed to fetch; clean up */
 			git_repository_free(repo);
-			git_futils_rmdir_r(path, NULL, GIT_DIRREMOVAL_FILES_AND_DIRS);
+			git_futils_rmdir_r(path, NULL, GIT_RMDIR_REMOVE_FILES);
 		} else {
 			*out = repo;
 			retcode = 0;
diff --git a/src/diff.c b/src/diff.c
index 55f6ee7d5..6f48d72a2 100644
--- a/src/diff.c
+++ b/src/diff.c
@@ -10,76 +10,7 @@
 #include "config.h"
 #include "attr_file.h"
 #include "filter.h"
-
-static char *diff_prefix_from_pathspec(const git_strarray *pathspec)
-{
-	git_buf prefix = GIT_BUF_INIT;
-	const char *scan;
-
-	if (git_buf_common_prefix(&prefix, pathspec) < 0)
-		return NULL;
-
-	/* diff prefix will only be leading non-wildcards */
-	for (scan = prefix.ptr; *scan; ++scan) {
-		if (git__iswildcard(*scan) &&
-			(scan == prefix.ptr || (*(scan - 1) != '\\')))
-			break;
-	}
-	git_buf_truncate(&prefix, scan - prefix.ptr);
-
-	if (prefix.size <= 0) {
-		git_buf_free(&prefix);
-		return NULL;
-	}
-
-	git_buf_unescape(&prefix);
-
-	return git_buf_detach(&prefix);
-}
-
-static bool diff_pathspec_is_interesting(const git_strarray *pathspec)
-{
-	const char *str;
-
-	if (pathspec == NULL || pathspec->count == 0)
-		return false;
-	if (pathspec->count > 1)
-		return true;
-
-	str = pathspec->strings[0];
-	if (!str || !str[0] || (!str[1] && (str[0] == '*' || str[0] == '.')))
-		return false;
-	return true;
-}
-
-static bool diff_path_matches_pathspec(git_diff_list *diff, const char *path)
-{
-	unsigned int i;
-	git_attr_fnmatch *match;
-
-	if (!diff->pathspec.length)
-		return true;
-
-	git_vector_foreach(&diff->pathspec, i, match) {
-		int result = strcmp(match->pattern, path) ? FNM_NOMATCH : 0;
-
-		if (((diff->opts.flags & GIT_DIFF_DISABLE_PATHSPEC_MATCH) == 0) &&
-			result == FNM_NOMATCH)
-			result = p_fnmatch(match->pattern, path, 0);
-
-		/* if we didn't match, look for exact dirname prefix match */
-		if (result == FNM_NOMATCH &&
-			(match->flags & GIT_ATTR_FNMATCH_HASWILD) == 0 &&
-			strncmp(path, match->pattern, match->length) == 0 &&
-			path[match->length] == '/')
-			result = 0;
-
-		if (result == 0)
-			return (match->flags & GIT_ATTR_FNMATCH_NEGATIVE) ? false : true;
-	}
-
-	return false;
-}
+#include "pathspec.h"
 
 static git_diff_delta *diff_delta__alloc(
 	git_diff_list *diff,
@@ -125,7 +56,10 @@ static int diff_delta__from_one(
 		(diff->opts.flags & GIT_DIFF_INCLUDE_UNTRACKED) == 0)
 		return 0;
 
-	if (!diff_path_matches_pathspec(diff, entry->path))
+	if (!git_pathspec_match_path(
+			&diff->pathspec, entry->path,
+			(diff->opts.flags & GIT_DIFF_DISABLE_PATHSPEC_MATCH) != 0,
+			(diff->opts.flags & GIT_DIFF_DELTAS_ARE_ICASE) != 0))
 		return 0;
 
 	delta = diff_delta__alloc(diff, status, entry->path);
@@ -295,7 +229,6 @@ static git_diff_list *git_diff_list_alloc(
 	git_repository *repo, const git_diff_options *opts)
 {
 	git_config *cfg;
-	size_t i;
 	git_diff_list *diff = git__calloc(1, sizeof(git_diff_list));
 	if (diff == NULL)
 		return NULL;
@@ -333,7 +266,10 @@ static git_diff_list *git_diff_list_alloc(
 		return diff;
 
 	memcpy(&diff->opts, opts, sizeof(git_diff_options));
-	memset(&diff->opts.pathspec, 0, sizeof(diff->opts.pathspec));
+
+	/* pathspec init will do nothing for empty pathspec */
+	if (git_pathspec_init(&diff->pathspec, &opts->pathspec, &diff->pool) < 0)
+		goto fail;
 
 	/* TODO: handle config diff.mnemonicprefix, diff.noprefix */
 
@@ -355,35 +291,6 @@ static git_diff_list *git_diff_list_alloc(
 	if (diff->opts.flags & GIT_DIFF_INCLUDE_TYPECHANGE_TREES)
 		diff->opts.flags |= GIT_DIFF_INCLUDE_TYPECHANGE;
 
-	/* only copy pathspec if it is "interesting" so we can test
-	 * diff->pathspec.length > 0 to know if it is worth calling
-	 * fnmatch as we iterate.
-	 */
-	if (!diff_pathspec_is_interesting(&opts->pathspec))
-		return diff;
-
-	if (git_vector_init(
-		&diff->pathspec, (unsigned int)opts->pathspec.count, NULL) < 0)
-		goto fail;
-
-	for (i = 0; i < opts->pathspec.count; ++i) {
-		int ret;
-		const char *pattern = opts->pathspec.strings[i];
-		git_attr_fnmatch *match = git__calloc(1, sizeof(git_attr_fnmatch));
-		if (!match)
-			goto fail;
-		match->flags = GIT_ATTR_FNMATCH_ALLOWSPACE;
-		ret = git_attr_fnmatch__parse(match, &diff->pool, NULL, &pattern);
-		if (ret == GIT_ENOTFOUND) {
-			git__free(match);
-			continue;
-		} else if (ret < 0)
-			goto fail;
-
-		if (git_vector_insert(&diff->pathspec, match) < 0)
-			goto fail;
-	}
-
 	return diff;
 
 fail:
@@ -394,7 +301,6 @@ fail:
 static void diff_list_free(git_diff_list *diff)
 {
 	git_diff_delta *delta;
-	git_attr_fnmatch *match;
 	unsigned int i;
 
 	git_vector_foreach(&diff->deltas, i, delta) {
@@ -403,12 +309,7 @@ static void diff_list_free(git_diff_list *diff)
 	}
 	git_vector_free(&diff->deltas);
 
-	git_vector_foreach(&diff->pathspec, i, match) {
-		git__free(match);
-		diff->pathspec.contents[i] = NULL;
-	}
-	git_vector_free(&diff->pathspec);
-
+	git_pathspec_free(&diff->pathspec);
 	git_pool_clear(&diff->pool);
 	git__free(diff);
 }
@@ -426,24 +327,39 @@ void git_diff_list_addref(git_diff_list *diff)
 	GIT_REFCOUNT_INC(diff);
 }
 
-static int oid_for_workdir_item(
+int git_diff__oid_for_file(
 	git_repository *repo,
-	const git_index_entry *item,
+	const char *path,
+	uint16_t  mode,
+	git_off_t size,
 	git_oid *oid)
 {
 	int result = 0;
 	git_buf full_path = GIT_BUF_INIT;
 
 	if (git_buf_joinpath(
-		&full_path, git_repository_workdir(repo), item->path) < 0)
+		&full_path, git_repository_workdir(repo), path) < 0)
 		return -1;
 
+	if (!mode) {
+		struct stat st;
+
+		if (p_stat(path, &st) < 0) {
+			giterr_set(GITERR_OS, "Could not stat '%s'", path);
+			result = -1;
+			goto cleanup;
+		}
+
+		mode = st.st_mode;
+		size = st.st_size;
+	}
+
 	/* calculate OID for file if possible */
-	if (S_ISGITLINK(item->mode)) {
+	if (S_ISGITLINK(mode)) {
 		git_submodule *sm;
 		const git_oid *sm_oid;
 
-		if (!git_submodule_lookup(&sm, repo, item->path) &&
+		if (!git_submodule_lookup(&sm, repo, path) &&
 			(sm_oid = git_submodule_wd_oid(sm)) != NULL)
 			git_oid_cpy(oid, sm_oid);
 		else {
@@ -453,23 +369,22 @@ static int oid_for_workdir_item(
 			giterr_clear();
 			memset(oid, 0, sizeof(*oid));
 		}
-	} else if (S_ISLNK(item->mode))
+	} else if (S_ISLNK(mode)) {
 		result = git_odb__hashlink(oid, full_path.ptr);
-	else if (!git__is_sizet(item->file_size)) {
-		giterr_set(GITERR_OS, "File size overflow for 32-bit systems");
+	} else if (!git__is_sizet(size)) {
+		giterr_set(GITERR_OS, "File size overflow (for 32-bits) on '%s'", path);
 		result = -1;
 	} else {
 		git_vector filters = GIT_VECTOR_INIT;
 
-		result = git_filters_load(
-			&filters, repo, item->path, GIT_FILTER_TO_ODB);
+		result = git_filters_load(&filters, repo, path, GIT_FILTER_TO_ODB);
 		if (result >= 0) {
 			int fd = git_futils_open_ro(full_path.ptr);
 			if (fd < 0)
 				result = fd;
 			else {
 				result = git_odb__hashfd_filtered(
-					oid, fd, (size_t)item->file_size, GIT_OBJ_BLOB, &filters);
+					oid, fd, (size_t)size, GIT_OBJ_BLOB, &filters);
 				p_close(fd);
 			}
 		}
@@ -477,8 +392,8 @@ static int oid_for_workdir_item(
 		git_filters_free(&filters);
 	}
 
+cleanup:
 	git_buf_free(&full_path);
-
 	return result;
 }
 
@@ -499,7 +414,10 @@ static int maybe_modified(
 
 	GIT_UNUSED(old_iter);
 
-	if (!diff_path_matches_pathspec(diff, oitem->path))
+	if (!git_pathspec_match_path(
+			&diff->pathspec, oitem->path,
+			(diff->opts.flags & GIT_DIFF_DISABLE_PATHSPEC_MATCH) != 0,
+			(diff->opts.flags & GIT_DIFF_DELTAS_ARE_ICASE) != 0))
 		return 0;
 
 	/* on platforms with no symlinks, preserve mode of existing symlinks */
@@ -535,8 +453,7 @@ static int maybe_modified(
 	}
 
 	/* if oids and modes match, then file is unmodified */
-	else if (git_oid_cmp(&oitem->oid, &nitem->oid) == 0 &&
-			 omode == nmode)
+	else if (git_oid_equal(&oitem->oid, &nitem->oid) && omode == nmode)
 		status = GIT_DELTA_UNMODIFIED;
 
 	/* if we have an unknown OID and a workdir iterator, then check some
@@ -590,44 +507,28 @@ static int maybe_modified(
 	 * haven't calculated the OID of the new item, then calculate it now
 	 */
 	if (status != GIT_DELTA_UNMODIFIED && git_oid_iszero(&nitem->oid)) {
-		if (oid_for_workdir_item(diff->repo, nitem, &noid) < 0)
-			return -1;
-		else if (omode == nmode && git_oid_equal(&oitem->oid, &noid))
+		if (!use_noid) {
+			if (git_diff__oid_for_file(diff->repo,
+					nitem->path, nitem->mode, nitem->file_size, &noid) < 0)
+				return -1;
+			use_noid = &noid;
+		}
+		if (omode == nmode && git_oid_equal(&oitem->oid, use_noid))
 			status = GIT_DELTA_UNMODIFIED;
-
-		/* store calculated oid so we don't have to recalc later */
-		use_noid = &noid;
 	}
 
 	return diff_delta__from_two(
 		diff, status, oitem, omode, nitem, nmode, use_noid);
 }
 
-static int git_index_entry_cmp_case(const void *a, const void *b)
-{
-	const git_index_entry *entry_a = a;
-	const git_index_entry *entry_b = b;
-
-	return strcmp(entry_a->path, entry_b->path);
-}
-
-static int git_index_entry_cmp_icase(const void *a, const void *b)
-{
-	const git_index_entry *entry_a = a;
-	const git_index_entry *entry_b = b;
-
-	return strcasecmp(entry_a->path, entry_b->path);
-}
-
 static bool entry_is_prefixed(
+	git_diff_list *diff,
 	const git_index_entry *item,
-	git_iterator *prefix_iterator,
 	const git_index_entry *prefix_item)
 {
 	size_t pathlen;
 
-	if (!prefix_item ||
-		ITERATOR_PREFIXCMP(*prefix_iterator, prefix_item->path, item->path))
+	if (!prefix_item || diff->pfxcomp(prefix_item->path, item->path))
 		return false;
 
 	pathlen = strlen(item->path);
@@ -637,6 +538,35 @@ static bool entry_is_prefixed(
 			prefix_item->path[pathlen] == '/');
 }
 
+static int diff_list_init_from_iterators(
+	git_diff_list *diff,
+	git_iterator *old_iter,
+	git_iterator *new_iter)
+{
+	diff->old_src = old_iter->type;
+	diff->new_src = new_iter->type;
+
+	/* Use case-insensitive compare if either iterator has
+	 * the ignore_case bit set */
+	if (!old_iter->ignore_case && !new_iter->ignore_case) {
+		diff->opts.flags &= ~GIT_DIFF_DELTAS_ARE_ICASE;
+
+		diff->strcomp    = strcmp;
+		diff->strncomp   = strncmp;
+		diff->pfxcomp    = git__prefixcmp;
+		diff->entrycomp  = git_index_entry__cmp;
+	} else {
+		diff->opts.flags |= GIT_DIFF_DELTAS_ARE_ICASE;
+
+		diff->strcomp    = strcasecmp;
+		diff->strncomp   = strncasecmp;
+		diff->pfxcomp    = git__prefixcmp_icase;
+		diff->entrycomp  = git_index_entry__cmp_icase;
+	}
+
+	return 0;
+}
+
 static int diff_from_iterators(
 	git_repository *repo,
 	const git_diff_options *opts, /**< can be NULL for defaults */
@@ -644,37 +574,31 @@ static int diff_from_iterators(
 	git_iterator *new_iter,
 	git_diff_list **diff_ptr)
 {
+	int error = 0;
 	const git_index_entry *oitem, *nitem;
 	git_buf ignore_prefix = GIT_BUF_INIT;
 	git_diff_list *diff = git_diff_list_alloc(repo, opts);
-	git_vector_cmp entry_compare;
 
-	if (!diff)
-		goto fail;
-
-	diff->old_src = old_iter->type;
-	diff->new_src = new_iter->type;
+	*diff_ptr = NULL;
 
-	/* Use case-insensitive compare if either iterator has
-	 * the ignore_case bit set */
-	if (!old_iter->ignore_case && !new_iter->ignore_case) {
-		entry_compare = git_index_entry_cmp_case;
-		diff->opts.flags &= ~GIT_DIFF_DELTAS_ARE_ICASE;
-	} else {
-		entry_compare = git_index_entry_cmp_icase;
-		diff->opts.flags |= GIT_DIFF_DELTAS_ARE_ICASE;
+	if (!diff ||
+		diff_list_init_from_iterators(diff, old_iter, new_iter) < 0)
+		goto fail;
 
+	if (diff->opts.flags & GIT_DIFF_DELTAS_ARE_ICASE) {
 		/* If one of the iterators doesn't have ignore_case set,
 		 * then that's unfortunate because we'll have to spool
 		 * its data, sort it icase, and then use that for our
 		 * merge join to the other iterator that is icase sorted */
-		if (!old_iter->ignore_case) {
-			if (git_iterator_spoolandsort(&old_iter, old_iter, git_index_entry_cmp_icase, true) < 0)
-				goto fail;
-		} else if (!new_iter->ignore_case) {
-			if (git_iterator_spoolandsort(&new_iter, new_iter, git_index_entry_cmp_icase, true) < 0)
-				goto fail;
-		}
+		if (!old_iter->ignore_case &&
+			git_iterator_spoolandsort(
+				&old_iter, old_iter, diff->entrycomp, true) < 0)
+			goto fail;
+
+		if (!new_iter->ignore_case &&
+			git_iterator_spoolandsort(
+				&new_iter, new_iter, diff->entrycomp, true) < 0)
+			goto fail;
 	}
 
 	if (git_iterator_current(old_iter, &oitem) < 0 ||
@@ -685,7 +609,7 @@ static int diff_from_iterators(
 	while (oitem || nitem) {
 
 		/* create DELETED records for old items not matched in new */
-		if (oitem && (!nitem || entry_compare(oitem, nitem) < 0)) {
+		if (oitem && (!nitem || diff->entrycomp(oitem, nitem) < 0)) {
 			if (diff_delta__from_one(diff, GIT_DELTA_DELETED, oitem) < 0)
 				goto fail;
 
@@ -693,7 +617,7 @@ static int diff_from_iterators(
 			 * instead of just generating a DELETE record
 			 */
 			if ((diff->opts.flags & GIT_DIFF_INCLUDE_TYPECHANGE_TREES) != 0 &&
-				entry_is_prefixed(oitem, new_iter, nitem))
+				entry_is_prefixed(diff, oitem, nitem))
 			{
 				/* this entry has become a tree! convert to TYPECHANGE */
 				git_diff_delta *last = diff_delta__last_for_item(diff, oitem);
@@ -710,13 +634,12 @@ static int diff_from_iterators(
 		/* create ADDED, TRACKED, or IGNORED records for new items not
 		 * matched in old (and/or descend into directories as needed)
 		 */
-		else if (nitem && (!oitem || entry_compare(oitem, nitem) > 0)) {
+		else if (nitem && (!oitem || diff->entrycomp(oitem, nitem) > 0)) {
 			git_delta_t delta_type = GIT_DELTA_UNTRACKED;
 
 			/* check if contained in ignored parent directory */
 			if (git_buf_len(&ignore_prefix) &&
-				ITERATOR_PREFIXCMP(*old_iter, nitem->path,
-					git_buf_cstr(&ignore_prefix)) == 0)
+				diff->pfxcomp(nitem->path, git_buf_cstr(&ignore_prefix)) == 0)
 				delta_type = GIT_DELTA_IGNORED;
 
 			if (S_ISDIR(nitem->mode)) {
@@ -725,7 +648,7 @@ static int diff_from_iterators(
 				 * directories and it is not under an ignored directory.
 				 */
 				bool contains_tracked =
-					entry_is_prefixed(nitem, old_iter, oitem);
+					entry_is_prefixed(diff, nitem, oitem);
 				bool recurse_untracked =
 					(delta_type == GIT_DELTA_UNTRACKED &&
 					 (diff->opts.flags & GIT_DIFF_RECURSE_UNTRACKED_DIRS) != 0);
@@ -789,7 +712,7 @@ static int diff_from_iterators(
 			 */
 			if (delta_type != GIT_DELTA_IGNORED &&
 				(diff->opts.flags & GIT_DIFF_INCLUDE_TYPECHANGE_TREES) != 0 &&
-				entry_is_prefixed(nitem, old_iter, oitem))
+				entry_is_prefixed(diff, nitem, oitem))
 			{
 				/* this entry was a tree! convert to TYPECHANGE */
 				git_diff_delta *last = diff_delta__last_for_item(diff, oitem);
@@ -807,7 +730,7 @@ static int diff_from_iterators(
 		 * (or ADDED and DELETED pair if type changed)
 		 */
 		else {
-			assert(oitem && nitem && entry_compare(oitem, nitem) == 0);
+			assert(oitem && nitem && diff->entrycomp(oitem, nitem) == 0);
 
 			if (maybe_modified(old_iter, oitem, new_iter, nitem, diff) < 0 ||
 				git_iterator_advance(old_iter, &oitem) < 0 ||
@@ -816,21 +739,19 @@ static int diff_from_iterators(
 		}
 	}
 
-	git_iterator_free(old_iter);
-	git_iterator_free(new_iter);
-	git_buf_free(&ignore_prefix);
-
 	*diff_ptr = diff;
-	return 0;
 
 fail:
+	if (!*diff_ptr) {
+		git_diff_list_free(diff);
+		error = -1;
+	}
+
 	git_iterator_free(old_iter);
 	git_iterator_free(new_iter);
 	git_buf_free(&ignore_prefix);
 
-	git_diff_list_free(diff);
-	*diff_ptr = NULL;
-	return -1;
+	return error;
 }
 
 
@@ -842,15 +763,15 @@ int git_diff_tree_to_tree(
 	git_diff_list **diff)
 {
 	git_iterator *a = NULL, *b = NULL;
-	char *prefix = opts ? diff_prefix_from_pathspec(&opts->pathspec) : NULL;
+	char *pfx = opts ? git_pathspec_prefix(&opts->pathspec) : NULL;
 
 	assert(repo && old_tree && new_tree && diff);
 
-	if (git_iterator_for_tree_range(&a, repo, old_tree, prefix, prefix) < 0 ||
-		git_iterator_for_tree_range(&b, repo, new_tree, prefix, prefix) < 0)
+	if (git_iterator_for_tree_range(&a, repo, old_tree, pfx, pfx) < 0 ||
+		git_iterator_for_tree_range(&b, repo, new_tree, pfx, pfx) < 0)
 		return -1;
 
-	git__free(prefix);
+	git__free(pfx);
 
 	return diff_from_iterators(repo, opts, a, b, diff);
 }
@@ -862,20 +783,20 @@ int git_diff_index_to_tree(
 	git_diff_list **diff)
 {
 	git_iterator *a = NULL, *b = NULL;
-	char *prefix = opts ? diff_prefix_from_pathspec(&opts->pathspec) : NULL;
+	char *pfx = opts ? git_pathspec_prefix(&opts->pathspec) : NULL;
 
 	assert(repo && diff);
 
-	if (git_iterator_for_tree_range(&a, repo, old_tree, prefix, prefix) < 0 ||
-	    git_iterator_for_index_range(&b, repo, prefix, prefix) < 0)
+	if (git_iterator_for_tree_range(&a, repo, old_tree, pfx, pfx) < 0 ||
+	    git_iterator_for_index_range(&b, repo, pfx, pfx) < 0)
 		goto on_error;
 
-	git__free(prefix);
+	git__free(pfx);
 
 	return diff_from_iterators(repo, opts, a, b, diff);
 
 on_error:
-	git__free(prefix);
+	git__free(pfx);
 	git_iterator_free(a);
 	return -1;
 }
@@ -885,23 +806,22 @@ int git_diff_workdir_to_index(
 	const git_diff_options *opts,
 	git_diff_list **diff)
 {
-	git_iterator *a = NULL, *b = NULL;
 	int error;
-
-	char *prefix = opts ? diff_prefix_from_pathspec(&opts->pathspec) : NULL;
+	git_iterator *a = NULL, *b = NULL;
+	char *pfx = opts ? git_pathspec_prefix(&opts->pathspec) : NULL;
 
 	assert(repo && diff);
 
-	if ((error = git_iterator_for_index_range(&a, repo, prefix, prefix)) < 0 ||
-	    (error = git_iterator_for_workdir_range(&b, repo, prefix, prefix)) < 0)
+	if ((error = git_iterator_for_index_range(&a, repo, pfx, pfx)) < 0 ||
+	    (error = git_iterator_for_workdir_range(&b, repo, pfx, pfx)) < 0)
 		goto on_error;
 
-	git__free(prefix);
+	git__free(pfx);
 
 	return diff_from_iterators(repo, opts, a, b, diff);
 
 on_error:
-	git__free(prefix);
+	git__free(pfx);
 	git_iterator_free(a);
 	return error;
 }
@@ -910,26 +830,25 @@ on_error:
 int git_diff_workdir_to_tree(
 	git_repository *repo,
 	const git_diff_options *opts,
-	git_tree *old_tree,
+	git_tree *tree,
 	git_diff_list **diff)
 {
-	git_iterator *a = NULL, *b = NULL;
 	int error;
+	git_iterator *a = NULL, *b = NULL;
+	char *pfx = opts ? git_pathspec_prefix(&opts->pathspec) : NULL;
 
-	char *prefix = opts ? diff_prefix_from_pathspec(&opts->pathspec) : NULL;
-
-	assert(repo && old_tree && diff);
+	assert(repo && tree && diff);
 
-	if ((error = git_iterator_for_tree_range(&a, repo, old_tree, prefix, prefix)) < 0 ||
-	    (error = git_iterator_for_workdir_range(&b, repo, prefix, prefix)) < 0)
+	if ((error = git_iterator_for_tree_range(&a, repo, tree, pfx, pfx)) < 0 ||
+	    (error = git_iterator_for_workdir_range(&b, repo, pfx, pfx)) < 0)
 		goto on_error;
 
-	git__free(prefix);
+	git__free(pfx);
 
 	return diff_from_iterators(repo, opts, a, b, diff);
 
 on_error:
-	git__free(prefix);
+	git__free(pfx);
 	git_iterator_free(a);
 	return error;
 }
diff --git a/src/diff.h b/src/diff.h
index ed66439bf..1e3be7593 100644
--- a/src/diff.h
+++ b/src/diff.h
@@ -41,6 +41,11 @@ struct git_diff_list {
 	git_iterator_type_t old_src;
 	git_iterator_type_t new_src;
 	uint32_t diffcaps;
+
+	int (*strcomp)(const char *, const char *);
+	int (*strncomp)(const char *, const char *, size_t);
+	int (*pfxcomp)(const char *str, const char *pfx);
+	int (*entrycomp)(const void *a, const void *b);
 };
 
 extern void git_diff__cleanup_modes(
@@ -53,5 +58,8 @@ extern int git_diff_delta__cmp(const void *a, const void *b);
 extern bool git_diff_delta__should_skip(
 	const git_diff_options *opts, const git_diff_delta *delta);
 
+extern int git_diff__oid_for_file(
+	git_repository *, const char *, uint16_t, git_off_t, git_oid *);
+
 #endif
 
diff --git a/src/diff_output.c b/src/diff_output.c
index e678ec857..46a9e02bf 100644
--- a/src/diff_output.c
+++ b/src/diff_output.c
@@ -120,7 +120,7 @@ static int diff_delta_is_binary_by_attr(
 		return -1;
 
 	mirror_new = (delta->new_file.path == delta->old_file.path ||
-				  strcmp(delta->new_file.path, delta->old_file.path) == 0);
+		ctxt->diff->strcomp(delta->new_file.path, delta->old_file.path) == 0);
 	if (mirror_new)
 		delta->new_file.flags |= (delta->old_file.flags & KNOWN_BINARY_FLAGS);
 	else
@@ -1002,7 +1002,7 @@ static int print_compact(
 	git_buf_clear(pi->buf);
 
 	if (delta->old_file.path != delta->new_file.path &&
-		strcmp(delta->old_file.path,delta->new_file.path) != 0)
+		pi->diff->strcomp(delta->old_file.path,delta->new_file.path) != 0)
 		git_buf_printf(pi->buf, "%c\t%s%c -> %s%c\n", code,
 			delta->old_file.path, old_suffix, delta->new_file.path, new_suffix);
 	else if (delta->old_file.mode != delta->new_file.mode &&
@@ -1573,3 +1573,58 @@ int git_diff_patch_to_str(
 
 	return error;
 }
+
+int git_diff__paired_foreach(
+	git_diff_list *idx2head,
+	git_diff_list *wd2idx,
+	int (*cb)(void *cbref, git_diff_delta *i2h, git_diff_delta *w2i),
+	void *cbref)
+{
+	int cmp;
+	git_diff_delta *i2h, *w2i;
+	size_t i, j, i_max, j_max;
+	bool icase = false;
+
+	i_max = idx2head ? idx2head->deltas.length : 0;
+	j_max = wd2idx   ? wd2idx->deltas.length   : 0;
+
+	if (idx2head && wd2idx &&
+		(0 != (idx2head->opts.flags & GIT_DIFF_DELTAS_ARE_ICASE) ||
+		 0 != (wd2idx->opts.flags & GIT_DIFF_DELTAS_ARE_ICASE)))
+	{
+		/* Then use the ignore-case sorter... */
+		icase = true;
+
+		/* and assert that both are ignore-case sorted. If this function
+		 * ever needs to support merge joining result sets that are not sorted
+		 * by the same function, then it will need to be extended to do a spool
+		 * and sort on one of the results before merge joining */
+		assert(0 != (idx2head->opts.flags & GIT_DIFF_DELTAS_ARE_ICASE) &&
+			0 != (wd2idx->opts.flags & GIT_DIFF_DELTAS_ARE_ICASE));
+	}
+
+	for (i = 0, j = 0; i < i_max || j < j_max; ) {
+		i2h = idx2head ? GIT_VECTOR_GET(&idx2head->deltas,i) : NULL;
+		w2i = wd2idx   ? GIT_VECTOR_GET(&wd2idx->deltas,j)   : NULL;
+
+		cmp = !w2i ? -1 : !i2h ? 1 :
+			STRCMP_CASESELECT(icase, i2h->old_file.path, w2i->old_file.path);
+
+		if (cmp < 0) {
+			if (cb(cbref, i2h, NULL))
+				return GIT_EUSER;
+			i++;
+		} else if (cmp > 0) {
+			if (cb(cbref, NULL, w2i))
+				return GIT_EUSER;
+			j++;
+		} else {
+			if (cb(cbref, i2h, w2i))
+				return GIT_EUSER;
+			i++; j++;
+		}
+	}
+
+	return 0;
+}
+
diff --git a/src/diff_output.h b/src/diff_output.h
index 5fed1d998..f74dd3a71 100644
--- a/src/diff_output.h
+++ b/src/diff_output.h
@@ -83,4 +83,10 @@ typedef struct {
 	uint32_t diffed   : 1;
 } diff_delta_context;
 
+extern int git_diff__paired_foreach(
+	git_diff_list *idx2head,
+	git_diff_list *wd2idx,
+	int (*cb)(void *cbref, git_diff_delta *i2h, git_diff_delta *w2i),
+	void *cbref);
+
 #endif
diff --git a/src/fileops.c b/src/fileops.c
index 2aceb112a..5eebc5057 100644
--- a/src/fileops.c
+++ b/src/fileops.c
@@ -14,7 +14,8 @@
 int git_futils_mkpath2file(const char *file_path, const mode_t mode)
 {
 	return git_futils_mkdir(
-		file_path, NULL, mode, GIT_MKDIR_PATH | GIT_MKDIR_SKIP_LAST);
+		file_path, NULL, mode,
+		GIT_MKDIR_PATH | GIT_MKDIR_SKIP_LAST | GIT_MKDIR_VERIFY_DIR);
 }
 
 int git_futils_mktmp(git_buf *path_out, const char *filename)
@@ -250,6 +251,7 @@ int git_futils_mkdir(
 	mode_t mode,
 	uint32_t flags)
 {
+	int error = -1;
 	git_buf make_path = GIT_BUF_INIT;
 	ssize_t root = 0;
 	char lastch, *tail;
@@ -297,12 +299,28 @@ int git_futils_mkdir(
 		*tail = '\0';
 
 		/* make directory */
-		if (p_mkdir(make_path.ptr, mode) < 0 &&
-			(errno != EEXIST || (flags & GIT_MKDIR_EXCL) != 0))
-		{
-			giterr_set(GITERR_OS, "Failed to make directory '%s'",
-				make_path.ptr);
-			goto fail;
+		if (p_mkdir(make_path.ptr, mode) < 0) {
+			if (errno == EEXIST) {
+				if (!lastch && (flags & GIT_MKDIR_VERIFY_DIR) != 0) {
+					if (!git_path_isdir(make_path.ptr)) {
+						giterr_set(
+							GITERR_OS, "Existing path is not a directory '%s'",
+							make_path.ptr);
+						error = GIT_ENOTFOUND;
+						goto fail;
+					}
+				}
+				if ((flags & GIT_MKDIR_EXCL) != 0) {
+					giterr_set(GITERR_OS, "Directory already exists '%s'",
+						make_path.ptr);
+					error = GIT_EEXISTS;
+					goto fail;
+				}
+			} else {
+				giterr_set(GITERR_OS, "Failed to make directory '%s'",
+					make_path.ptr);
+				goto fail;
+			}
 		}
 
 		/* chmod if requested */
@@ -324,7 +342,7 @@ int git_futils_mkdir(
 
 fail:
 	git_buf_free(&make_path);
-	return -1;
+	return error;
 }
 
 int git_futils_mkdir_r(const char *path, const char *base, const mode_t mode)
@@ -332,57 +350,145 @@ int git_futils_mkdir_r(const char *path, const char *base, const mode_t mode)
 	return git_futils_mkdir(path, base, mode, GIT_MKDIR_PATH);
 }
 
-static int _rmdir_recurs_foreach(void *opaque, git_buf *path)
+typedef struct {
+	const char *base;
+	uint32_t flags;
+	int error;
+} futils__rmdir_data;
+
+static int futils__error_cannot_rmdir(const char *path, const char *filemsg)
 {
-	git_directory_removal_type removal_type = *(git_directory_removal_type *)opaque;
+	if (filemsg)
+		giterr_set(GITERR_OS, "Could not remove directory. File '%s' %s",
+				   path, filemsg);
+	else
+		giterr_set(GITERR_OS, "Could not remove directory '%s'", path);
 
-	if (git_path_isdir(path->ptr) == true) {
-		if (git_path_direach(path, _rmdir_recurs_foreach, opaque) < 0)
-			return -1;
+	return -1;
+}
 
-		if (p_rmdir(path->ptr) < 0) {
-			if (removal_type == GIT_DIRREMOVAL_ONLY_EMPTY_DIRS && (errno == ENOTEMPTY || errno == EEXIST))
-				return 0;
+static int futils__rm_first_parent(git_buf *path, const char *ceiling)
+{
+	int error = GIT_ENOTFOUND;
+	struct stat st;
 
-			giterr_set(GITERR_OS, "Could not remove directory '%s'", path->ptr);
-			return -1;
-		}
+	while (error == GIT_ENOTFOUND) {
+		git_buf_rtruncate_at_char(path, '/');
+
+		if (!path->size || git__prefixcmp(path->ptr, ceiling) != 0)
+			error = 0;
+		else if (p_lstat(path->ptr, &st) == 0) {
+			if (S_ISREG(st.st_mode) || S_ISLNK(st.st_mode))
+				error = p_unlink(path->ptr);
+			else if (!S_ISDIR(st.st_mode))
+				error = -1; /* fail to remove non-regular file */
+		} else if (errno != ENOTDIR)
+			error = -1;
+	}
 
-		return 0;
+	if (error)
+		futils__error_cannot_rmdir(path->ptr, "cannot remove parent");
+
+	return error;
+}
+
+static int futils__rmdir_recurs_foreach(void *opaque, git_buf *path)
+{
+	struct stat st;
+	futils__rmdir_data *data = opaque;
+
+	if ((data->error = p_lstat(path->ptr, &st)) < 0) {
+		if (errno == ENOENT)
+			data->error = 0;
+		else if (errno == ENOTDIR) {
+			/* asked to remove a/b/c/d/e and a/b is a normal file */
+			if ((data->flags & GIT_RMDIR_REMOVE_BLOCKERS) != 0)
+				data->error = futils__rm_first_parent(path, data->base);
+			else
+				futils__error_cannot_rmdir(
+					path->ptr, "parent is not directory");
+		}
+		else
+			futils__error_cannot_rmdir(path->ptr, "cannot access");
 	}
 
-	if (removal_type == GIT_DIRREMOVAL_FILES_AND_DIRS) {
-		if (p_unlink(path->ptr) < 0) {
-			giterr_set(GITERR_OS, "Could not remove directory.  File '%s' cannot be removed", path->ptr);
-			return -1;
+	else if (S_ISDIR(st.st_mode)) {
+		int error = git_path_direach(path, futils__rmdir_recurs_foreach, data);
+		if (error < 0)
+			return (error == GIT_EUSER) ? data->error : error;
+
+		data->error = p_rmdir(path->ptr);
+
+		if (data->error < 0) {
+			if ((data->flags & GIT_RMDIR_SKIP_NONEMPTY) != 0 &&
+				(errno == ENOTEMPTY || errno == EEXIST))
+				data->error = 0;
+			else
+				futils__error_cannot_rmdir(path->ptr, NULL);
 		}
+	}
 
-		return 0;
+	else if ((data->flags & GIT_RMDIR_REMOVE_FILES) != 0) {
+		data->error = p_unlink(path->ptr);
+
+		if (data->error < 0)
+			futils__error_cannot_rmdir(path->ptr, "cannot be removed");
 	}
 
-	if (removal_type == GIT_DIRREMOVAL_EMPTY_HIERARCHY) {
-		giterr_set(GITERR_OS, "Could not remove directory. File '%s' still present", path->ptr);
-		return -1;
+	else if ((data->flags & GIT_RMDIR_SKIP_NONEMPTY) == 0)
+		data->error = futils__error_cannot_rmdir(path->ptr, "still present");
+
+	return data->error;
+}
+
+static int futils__rmdir_empty_parent(void *opaque, git_buf *path)
+{
+	int error = p_rmdir(path->ptr);
+
+	GIT_UNUSED(opaque);
+
+	if (error) {
+		int en = errno;
+
+		if (en == ENOENT || en == ENOTDIR) {
+			giterr_clear();
+			error = 0;
+		} else if (en == ENOTEMPTY || en == EEXIST) {
+			giterr_clear();
+			error = GIT_ITEROVER;
+		} else {
+			futils__error_cannot_rmdir(path->ptr, NULL);
+		}
 	}
 
-	return 0;
+	return error;
 }
 
 int git_futils_rmdir_r(
-	const char *path, const char *base, git_directory_removal_type removal_type)
+	const char *path, const char *base, uint32_t flags)
 {
 	int error;
 	git_buf fullpath = GIT_BUF_INIT;
-
-	assert(removal_type == GIT_DIRREMOVAL_EMPTY_HIERARCHY
-		|| removal_type == GIT_DIRREMOVAL_FILES_AND_DIRS
-		|| removal_type == GIT_DIRREMOVAL_ONLY_EMPTY_DIRS);
+	futils__rmdir_data data;
 
 	/* build path and find "root" where we should start calling mkdir */
 	if (git_path_join_unrooted(&fullpath, path, base, NULL) < 0)
 		return -1;
 
-	error = _rmdir_recurs_foreach(&removal_type, &fullpath);
+	data.base  = base ? base : "";
+	data.flags = flags;
+	data.error = 0;
+
+	error = futils__rmdir_recurs_foreach(&data, &fullpath);
+
+	/* remove now-empty parents if requested */
+	if (!error && (flags & GIT_RMDIR_EMPTY_PARENTS) != 0) {
+		error = git_path_walk_up(
+			&fullpath, base, futils__rmdir_empty_parent, &data);
+
+		if (error == GIT_ITEROVER)
+			error = 0;
+	}
 
 	git_buf_free(&fullpath);
 
diff --git a/src/fileops.h b/src/fileops.h
index 25e62c504..a74f8b758 100644
--- a/src/fileops.h
+++ b/src/fileops.h
@@ -65,6 +65,7 @@ extern int git_futils_mkdir_r(const char *path, const char *base, const mode_t m
  * * GIT_MKDIR_CHMOD says to chmod the final directory entry after creation
  * * GIT_MKDIR_CHMOD_PATH says to chmod each directory component in the path
  * * GIT_MKDIR_SKIP_LAST says to leave off the last element of the path
+ * * GIT_MKDIR_VERIFY_DIR says confirm final item is a dir, not just EEXIST
  *
  * Note that the chmod options will be executed even if the directory already
  * exists, unless GIT_MKDIR_EXCL is given.
@@ -74,7 +75,8 @@ typedef enum {
 	GIT_MKDIR_PATH = 2,
 	GIT_MKDIR_CHMOD = 4,
 	GIT_MKDIR_CHMOD_PATH = 8,
-	GIT_MKDIR_SKIP_LAST = 16
+	GIT_MKDIR_SKIP_LAST = 16,
+	GIT_MKDIR_VERIFY_DIR = 32,
 } git_futils_mkdir_flags;
 
 /**
@@ -98,27 +100,40 @@ extern int git_futils_mkdir(const char *path, const char *base, mode_t mode, uin
  */
 extern int git_futils_mkpath2file(const char *path, const mode_t mode);
 
+/**
+ * Flags to pass to `git_futils_rmdir_r`.
+ *
+ * * GIT_RMDIR_EMPTY_HIERARCHY - the default; remove hierarchy of empty
+ *       dirs and generate error if any files are found.
+ * * GIT_RMDIR_REMOVE_FILES    - attempt to remove files in the hierarchy.
+ * * GIT_RMDIR_SKIP_NONEMPTY   - skip non-empty directories with no error.
+ * * GIT_RMDIR_EMPTY_PARENTS   - remove containing directories up to base
+ *       if removing this item leaves them empty
+ * * GIT_RMDIR_REMOVE_BLOCKERS - remove blocking file that causes ENOTDIR
+ *
+ * The old values translate into the new as follows:
+ *
+ * * GIT_DIRREMOVAL_EMPTY_HIERARCHY == GIT_RMDIR_EMPTY_HIERARCHY
+ * * GIT_DIRREMOVAL_FILES_AND_DIRS  ~= GIT_RMDIR_REMOVE_FILES
+ * * GIT_DIRREMOVAL_ONLY_EMPTY_DIRS == GIT_RMDIR_SKIP_NONEMPTY
+ */
 typedef enum {
-	GIT_DIRREMOVAL_EMPTY_HIERARCHY = 0,
-	GIT_DIRREMOVAL_FILES_AND_DIRS = 1,
-	GIT_DIRREMOVAL_ONLY_EMPTY_DIRS = 2,
-} git_directory_removal_type;
+	GIT_RMDIR_EMPTY_HIERARCHY = 0,
+	GIT_RMDIR_REMOVE_FILES    = (1 << 0),
+	GIT_RMDIR_SKIP_NONEMPTY   = (1 << 1),
+	GIT_RMDIR_EMPTY_PARENTS   = (1 << 2),
+	GIT_RMDIR_REMOVE_BLOCKERS = (1 << 3),
+} git_futils_rmdir_flags;
 
 /**
  * Remove path and any files and directories beneath it.
  *
  * @param path Path to to top level directory to process.
  * @param base Root for relative path.
- * @param removal_type GIT_DIRREMOVAL_EMPTY_HIERARCHY to remove a hierarchy
- *                     of empty directories (will fail if any file is found),
- *                     GIT_DIRREMOVAL_FILES_AND_DIRS to remove a hierarchy of
- *                     files and folders,
- *                     GIT_DIRREMOVAL_ONLY_EMPTY_DIRS to only remove empty
- *                     directories (no failure on file encounter).
- *
+ * @param flags Combination of git_futils_rmdir_flags values
  * @return 0 on success; -1 on error.
  */
-extern int git_futils_rmdir_r(const char *path, const char *base, git_directory_removal_type removal_type);
+extern int git_futils_rmdir_r(const char *path, const char *base, uint32_t flags);
 
 /**
  * Create and open a temporary file with a `_git2_` suffix.
diff --git a/src/index.c b/src/index.c
index 06bbcacee..5a3532926 100644
--- a/src/index.c
+++ b/src/index.c
@@ -13,6 +13,8 @@
 #include "tree.h"
 #include "tree-cache.h"
 #include "hash.h"
+#include "iterator.h"
+#include "pathspec.h"
 #include "git2/odb.h"
 #include "git2/oid.h"
 #include "git2/blob.h"
@@ -403,7 +405,7 @@ int git_index_read(git_index *index)
 {
 	int error = 0, updated;
 	git_buf buffer = GIT_BUF_INIT;
-	git_futils_filestamp stamp;
+	git_futils_filestamp stamp = {0};
 
 	if (!index->index_file_path)
 		return create_index_error(-1,
@@ -513,7 +515,7 @@ git_index_entry *git_index_get_bypath(git_index *index, const char *path, int st
 	return git_index_get_byindex(index, pos);
 }
 
-void git_index__init_entry_from_stat(struct stat *st, git_index_entry *entry)
+void git_index_entry__init_from_stat(git_index_entry *entry, struct stat *st)
 {
 	entry->ctime.seconds = (git_time_t)st->st_ctime;
 	entry->mtime.seconds = (git_time_t)st->st_mtime;
@@ -527,6 +529,22 @@ void git_index__init_entry_from_stat(struct stat *st, git_index_entry *entry)
 	entry->file_size = st->st_size;
 }
 
+int git_index_entry__cmp(const void *a, const void *b)
+{
+	const git_index_entry *entry_a = a;
+	const git_index_entry *entry_b = b;
+
+	return strcmp(entry_a->path, entry_b->path);
+}
+
+int git_index_entry__cmp_icase(const void *a, const void *b)
+{
+	const git_index_entry *entry_a = a;
+	const git_index_entry *entry_b = b;
+
+	return strcasecmp(entry_a->path, entry_b->path);
+}
+
 static int index_entry_init(git_index_entry **entry_out, git_index *index, const char *rel_path)
 {
 	git_index_entry *entry = NULL;
@@ -568,7 +586,7 @@ static int index_entry_init(git_index_entry **entry_out, git_index *index, const
 	entry = git__calloc(1, sizeof(git_index_entry));
 	GITERR_CHECK_ALLOC(entry);
 
-	git_index__init_entry_from_stat(&st, entry);
+	git_index_entry__init_from_stat(entry, &st);
 
 	entry->oid = oid;
 	entry->path = git__strdup(rel_path);
@@ -1589,3 +1607,54 @@ git_repository *git_index_owner(const git_index *index)
 {
 	return INDEX_OWNER(index);
 }
+
+int git_index_read_tree_match(
+	git_index *index, git_tree *tree, git_strarray *strspec)
+{
+#if 0
+	git_iterator *iter = NULL;
+	const git_index_entry *entry;
+	char *pfx = NULL;
+	git_vector pathspec = GIT_VECTOR_INIT;
+	git_pool pathpool = GIT_POOL_INIT_STRINGPOOL;
+#endif
+
+	if (!git_pathspec_is_interesting(strspec))
+		return git_index_read_tree(index, tree);
+
+	return git_index_read_tree(index, tree);
+
+#if 0
+	/* The following loads the matches into the index, but doesn't
+	 * erase obsoleted entries (e.g. you load a blob at "a/b" which
+	 * should obsolete a blob at "a/b/c/d" since b is no longer a tree)
+	 */
+
+	if (git_pathspec_init(&pathspec, strspec, &pathpool) < 0)
+		return -1;
+
+	pfx = git_pathspec_prefix(strspec);
+
+	if ((error = git_iterator_for_tree_range(
+			 &iter, INDEX_OWNER(index), tree, pfx, pfx)) < 0 ||
+		(error = git_iterator_current(iter, &entry)) < 0)
+		goto cleanup;
+
+	while (entry != NULL) {
+		if (git_pathspec_match_path(&pathspec, entry->path, false, false) &&
+			(error = git_index_add(index, entry)) < 0)
+			goto cleanup;
+
+		if ((error = git_iterator_advance(iter, &entry)) < 0)
+			goto cleanup;
+	}
+
+cleanup:
+	git_iterator_free(iter);
+	git_pathspec_free(&pathspec);
+	git_pool_clear(&pathpool);
+	git__free(pfx);
+
+	return error;
+#endif
+}
diff --git a/src/index.h b/src/index.h
index 86158eb84..f0dcd64d5 100644
--- a/src/index.h
+++ b/src/index.h
@@ -41,8 +41,14 @@ struct git_index {
 	git_vector_cmp reuc_search;
 };
 
-extern void git_index__init_entry_from_stat(struct stat *st, git_index_entry *entry);
+extern void git_index_entry__init_from_stat(git_index_entry *entry, struct stat *st);
 
 extern unsigned int git_index__prefix_position(git_index *index, const char *path);
 
+extern int git_index_entry__cmp(const void *a, const void *b);
+extern int git_index_entry__cmp_icase(const void *a, const void *b);
+
+extern int git_index_read_tree_match(
+	git_index *index, git_tree *tree, git_strarray *strspec);
+
 #endif
diff --git a/src/iterator.c b/src/iterator.c
index 5fac41046..33b775ce1 100644
--- a/src/iterator.c
+++ b/src/iterator.c
@@ -641,26 +641,23 @@ static int workdir_iterator__update_entry(workdir_iterator *wi)
 
 	wi->entry.path = ps->path;
 
-	/* skip over .git entry */
+	/* skip over .git entries */
 	if (STRCMP_CASESELECT(wi->base.ignore_case, ps->path, DOT_GIT "/") == 0 ||
 		STRCMP_CASESELECT(wi->base.ignore_case, ps->path, DOT_GIT) == 0)
 		return workdir_iterator__advance((git_iterator *)wi, NULL);
 
-	/* if there is an error processing the entry, treat as ignored */
-	wi->is_ignored = 1;
+	wi->is_ignored = -1;
 
-	git_index__init_entry_from_stat(&ps->st, &wi->entry);
+	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)
+	if (wi->entry.mode == 0) {
+		wi->is_ignored = 1;
 		return 0;
-
-	/* okay, we are far enough along to look up real ignore rule */
-	if (git_ignore__lookup(&wi->ignores, wi->entry.path, &wi->is_ignored) < 0)
-		return 0; /* if error, ignore it and ignore file */
+	}
 
 	/* detect submodules */
 	if (S_ISDIR(wi->entry.mode)) {
@@ -908,8 +905,18 @@ notfound:
 
 int git_iterator_current_is_ignored(git_iterator *iter)
 {
-	return (iter->type != GIT_ITERATOR_WORKDIR) ? 0 :
-		((workdir_iterator *)iter)->is_ignored;
+	workdir_iterator *wi = (workdir_iterator *)iter;
+
+	if (iter->type != GIT_ITERATOR_WORKDIR)
+		return 0;
+
+	if (wi->is_ignored != -1)
+		return wi->is_ignored;
+
+	if (git_ignore__lookup(&wi->ignores, wi->entry.path, &wi->is_ignored) < 0)
+		wi->is_ignored = 1;
+
+	return wi->is_ignored;
 }
 
 int git_iterator_advance_into_directory(
diff --git a/src/pack-objects.c b/src/pack-objects.c
index f75267629..a146dc048 100644
--- a/src/pack-objects.c
+++ b/src/pack-objects.c
@@ -73,16 +73,16 @@ static int packbuilder_config(git_packbuilder *pb)
 {
 	git_config *config;
 	int ret;
+	int64_t val;
 
 	if (git_repository_config__weakptr(&config, pb->repo) < 0)
 		return -1;
 
-#define config_get(key, dst, default) \
-	ret = git_config_get_int64((int64_t *)&dst, config, key); \
-	if (ret == GIT_ENOTFOUND) \
-		dst = default; \
-	else if (ret < 0) \
-		return -1;
+#define config_get(KEY,DST,DFLT) do { \
+	ret = git_config_get_int64(&val, config, KEY); \
+	if (!ret) (DST) = val; \
+	else if (ret == GIT_ENOTFOUND) (DST) = (DFLT); \
+	else if (ret < 0) return -1; } while (0)
 
 	config_get("pack.deltaCacheSize", pb->max_delta_cache_size,
 		   GIT_PACK_DELTA_CACHE_SIZE);
diff --git a/src/path.c b/src/path.c
index 09556bd3f..98351bec3 100644
--- a/src/path.c
+++ b/src/path.c
@@ -382,9 +382,10 @@ int git_path_walk_up(
 	iter.asize = path->asize;
 
 	while (scan >= stop) {
-		if ((error = cb(data, &iter)) < 0)
-			break;
+		error = cb(data, &iter);
 		iter.ptr[scan] = oldc;
+		if (error < 0)
+			break;
 		scan = git_buf_rfind_next(&iter, '/');
 		if (scan >= 0) {
 			scan++;
diff --git a/src/pathspec.c b/src/pathspec.c
new file mode 100644
index 000000000..9632f5f13
--- /dev/null
+++ b/src/pathspec.c
@@ -0,0 +1,151 @@
+/*
+ * Copyright (C) 2009-2012 the libgit2 contributors
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "pathspec.h"
+#include "attr_file.h"
+
+/* what is the common non-wildcard prefix for all items in the pathspec */
+char *git_pathspec_prefix(const git_strarray *pathspec)
+{
+	git_buf prefix = GIT_BUF_INIT;
+	const char *scan;
+
+	if (!pathspec || !pathspec->count ||
+		git_buf_common_prefix(&prefix, pathspec) < 0)
+		return NULL;
+
+	/* diff prefix will only be leading non-wildcards */
+	for (scan = prefix.ptr; *scan; ++scan) {
+		if (git__iswildcard(*scan) &&
+			(scan == prefix.ptr || (*(scan - 1) != '\\')))
+			break;
+	}
+	git_buf_truncate(&prefix, scan - prefix.ptr);
+
+	if (prefix.size <= 0) {
+		git_buf_free(&prefix);
+		return NULL;
+	}
+
+	git_buf_unescape(&prefix);
+
+	return git_buf_detach(&prefix);
+}
+
+/* is there anything in the spec that needs to be filtered on */
+bool git_pathspec_is_interesting(const git_strarray *pathspec)
+{
+	const char *str;
+
+	if (pathspec == NULL || pathspec->count == 0)
+		return false;
+	if (pathspec->count > 1)
+		return true;
+
+	str = pathspec->strings[0];
+	if (!str || !str[0] || (!str[1] && (str[0] == '*' || str[0] == '.')))
+		return false;
+	return true;
+}
+
+/* build a vector of fnmatch patterns to evaluate efficiently */
+int git_pathspec_init(
+	git_vector *vspec, const git_strarray *strspec, git_pool *strpool)
+{
+	size_t i;
+
+	memset(vspec, 0, sizeof(*vspec));
+
+	if (!git_pathspec_is_interesting(strspec))
+		return 0;
+
+	if (git_vector_init(vspec, strspec->count, NULL) < 0)
+		return -1;
+
+	for (i = 0; i < strspec->count; ++i) {
+		int ret;
+		const char *pattern = strspec->strings[i];
+		git_attr_fnmatch *match = git__calloc(1, sizeof(git_attr_fnmatch));
+		if (!match)
+			return -1;
+
+		match->flags = GIT_ATTR_FNMATCH_ALLOWSPACE;
+
+		ret = git_attr_fnmatch__parse(match, strpool, NULL, &pattern);
+		if (ret == GIT_ENOTFOUND) {
+			git__free(match);
+			continue;
+		} else if (ret < 0)
+			return ret;
+
+		if (git_vector_insert(vspec, match) < 0)
+			return -1;
+	}
+
+	return 0;
+}
+
+/* free data from the pathspec vector */
+void git_pathspec_free(git_vector *vspec)
+{
+	git_attr_fnmatch *match;
+	unsigned int i;
+
+	git_vector_foreach(vspec, i, match) {
+		git__free(match);
+		vspec->contents[i] = NULL;
+	}
+
+	git_vector_free(vspec);
+}
+
+/* match a path against the vectorized pathspec */
+bool git_pathspec_match_path(
+	git_vector *vspec, const char *path, bool disable_fnmatch, bool casefold)
+{
+	unsigned int i;
+	git_attr_fnmatch *match;
+	int fnmatch_flags = 0;
+	int (*use_strcmp)(const char *, const char *);
+	int (*use_strncmp)(const char *, const char *, size_t);
+
+	if (!vspec || !vspec->length)
+		return true;
+
+	if (disable_fnmatch)
+		fnmatch_flags = -1;
+	else if (casefold)
+		fnmatch_flags = FNM_CASEFOLD;
+
+	if (casefold) {
+		use_strcmp  = strcasecmp;
+		use_strncmp = strncasecmp;
+	} else {
+		use_strcmp  = strcmp;
+		use_strncmp = strncmp;
+	}
+
+	git_vector_foreach(vspec, i, match) {
+		int result = use_strcmp(match->pattern, path) ? FNM_NOMATCH : 0;
+
+		if (fnmatch_flags >= 0 && result == FNM_NOMATCH)
+			result = p_fnmatch(match->pattern, path, fnmatch_flags);
+
+		/* if we didn't match, look for exact dirname prefix match */
+		if (result == FNM_NOMATCH &&
+			(match->flags & GIT_ATTR_FNMATCH_HASWILD) == 0 &&
+			use_strncmp(path, match->pattern, match->length) == 0 &&
+			path[match->length] == '/')
+			result = 0;
+
+		if (result == 0)
+			return (match->flags & GIT_ATTR_FNMATCH_NEGATIVE) ? false : true;
+	}
+
+	return false;
+}
+
diff --git a/src/pathspec.h b/src/pathspec.h
new file mode 100644
index 000000000..31a1cdad9
--- /dev/null
+++ b/src/pathspec.h
@@ -0,0 +1,32 @@
+/*
+ * Copyright (C) 2011-2012 the libgit2 contributors
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_pathspec_h__
+#define INCLUDE_pathspec_h__
+
+#include "common.h"
+#include "buffer.h"
+#include "vector.h"
+#include "pool.h"
+
+/* what is the common non-wildcard prefix for all items in the pathspec */
+extern char *git_pathspec_prefix(const git_strarray *pathspec);
+
+/* is there anything in the spec that needs to be filtered on */
+extern bool git_pathspec_is_interesting(const git_strarray *pathspec);
+
+/* build a vector of fnmatch patterns to evaluate efficiently */
+extern int git_pathspec_init(
+	git_vector *vspec, const git_strarray *strspec, git_pool *strpool);
+
+/* free data from the pathspec vector */
+extern void git_pathspec_free(git_vector *vspec);
+
+/* match a path against the vectorized pathspec */
+extern bool git_pathspec_match_path(
+	git_vector *vspec, const char *path, bool disable_fnmatch, bool casefold);
+
+#endif
diff --git a/src/reflog.c b/src/reflog.c
index 5d1465eca..0e333aa6f 100644
--- a/src/reflog.c
+++ b/src/reflog.c
@@ -378,7 +378,7 @@ int git_reflog_rename(git_reference *ref, const char *new_name)
 		goto cleanup;
 
 	if (git_path_isdir(git_buf_cstr(&new_path)) && 
-		(git_futils_rmdir_r(git_buf_cstr(&new_path), NULL, GIT_DIRREMOVAL_ONLY_EMPTY_DIRS) < 0))
+		(git_futils_rmdir_r(git_buf_cstr(&new_path), NULL, GIT_RMDIR_SKIP_NONEMPTY) < 0))
 		goto cleanup;
 
 	if (git_futils_mkpath2file(git_buf_cstr(&new_path), GIT_REFLOG_DIR_MODE) < 0)
diff --git a/src/refs.c b/src/refs.c
index bbf30ed9e..97c97563e 100644
--- a/src/refs.c
+++ b/src/refs.c
@@ -274,18 +274,15 @@ static int loose_write(git_reference *ref)
 	git_buf ref_path = GIT_BUF_INIT;
 	struct stat st;
 
-	if (git_buf_joinpath(&ref_path, ref->owner->path_repository, ref->name) < 0)
-		return -1;
-
 	/* Remove a possibly existing empty directory hierarchy
 	 * which name would collide with the reference name
 	 */
-	if (git_path_isdir(git_buf_cstr(&ref_path)) &&
-		git_futils_rmdir_r(git_buf_cstr(&ref_path), NULL,
-			GIT_DIRREMOVAL_ONLY_EMPTY_DIRS) < 0) {
-		git_buf_free(&ref_path);
+	if (git_futils_rmdir_r(ref->name, ref->owner->path_repository,
+		GIT_RMDIR_SKIP_NONEMPTY) < 0)
+		return -1;
+
+	if (git_buf_joinpath(&ref_path, ref->owner->path_repository, ref->name) < 0)
 		return -1;
-	}
 
 	if (git_filebuf_open(&file, ref_path.ptr, GIT_FILEBUF_FORCE) < 0) {
 		git_buf_free(&ref_path);
diff --git a/src/reset.c b/src/reset.c
index 7df1c1a57..69a9c4f04 100644
--- a/src/reset.c
+++ b/src/reset.c
@@ -137,10 +137,7 @@ int git_reset(
 	}
 
 	memset(&opts, 0, sizeof(opts));
-	opts.checkout_strategy =
-		GIT_CHECKOUT_CREATE_MISSING
-		| GIT_CHECKOUT_OVERWRITE_MODIFIED
-		| GIT_CHECKOUT_REMOVE_UNTRACKED;
+	opts.checkout_strategy = GIT_CHECKOUT_FORCE;
 
 	if (git_checkout_index(repo, &opts) < 0) {
 		giterr_set(GITERR_INDEX, "%s - Failed to checkout the index.", ERROR_MSG);
diff --git a/src/stash.c b/src/stash.c
index 1d6940e3c..7bff466d1 100644
--- a/src/stash.c
+++ b/src/stash.c
@@ -501,8 +501,8 @@ static int reset_index_and_workdir(
 
 	memset(&opts, 0, sizeof(git_checkout_opts));
 
-	opts.checkout_strategy = 
-		GIT_CHECKOUT_CREATE_MISSING | GIT_CHECKOUT_OVERWRITE_MODIFIED;
+	opts.checkout_strategy =
+		GIT_CHECKOUT_UPDATE_MODIFIED | GIT_CHECKOUT_UPDATE_UNTRACKED;
 
 	if (remove_untracked)
 		opts.checkout_strategy |= GIT_CHECKOUT_REMOVE_UNTRACKED;
diff --git a/src/status.c b/src/status.c
index 2d022bfda..0bd170e6d 100644
--- a/src/status.c
+++ b/src/status.c
@@ -17,6 +17,7 @@
 
 #include "git2/diff.h"
 #include "diff.h"
+#include "diff_output.h"
 
 static unsigned int index_delta2status(git_delta_t index_status)
 {
@@ -76,21 +77,43 @@ static unsigned int workdir_delta2status(git_delta_t workdir_status)
 	return st;
 }
 
+typedef struct {
+	int (*cb)(const char *, unsigned int, void *);
+	void *cbdata;
+} status_user_callback;
+
+static int status_invoke_cb(
+	void *cbref, git_diff_delta *i2h, git_diff_delta *w2i)
+{
+	status_user_callback *usercb = cbref;
+	const char *path = NULL;
+	unsigned int status = 0;
+
+	if (w2i) {
+		path = w2i->old_file.path;
+		status |= workdir_delta2status(w2i->status);
+	}
+	if (i2h) {
+		path = i2h->old_file.path;
+		status |= index_delta2status(i2h->status);
+	}
+
+	return usercb->cb(path, status, usercb->cbdata);
+}
+
 int git_status_foreach_ext(
 	git_repository *repo,
 	const git_status_options *opts,
 	int (*cb)(const char *, unsigned int, void *),
 	void *cbdata)
 {
-	int err = 0, cmp;
+	int err = 0;
 	git_diff_options diffopt;
 	git_diff_list *idx2head = NULL, *wd2idx = NULL;
 	git_tree *head = NULL;
 	git_status_show_t show =
 		opts ? opts->show : GIT_STATUS_SHOW_INDEX_AND_WORKDIR;
-	git_diff_delta *i2h, *w2i;
-	size_t i, j, i_max, j_max;
-	bool ignore_case = false;
+	status_user_callback usercb;
 
 	assert(show <= GIT_STATUS_SHOW_INDEX_THEN_WORKDIR);
 
@@ -126,55 +149,19 @@ int git_status_foreach_ext(
 		(err = git_diff_workdir_to_index(repo, &diffopt, &wd2idx)) < 0)
 		goto cleanup;
 
+	usercb.cb = cb;
+	usercb.cbdata = cbdata;
+
 	if (show == GIT_STATUS_SHOW_INDEX_THEN_WORKDIR) {
-		for (i = 0; !err && i < idx2head->deltas.length; i++) {
-			i2h = GIT_VECTOR_GET(&idx2head->deltas, i);
-			if (cb(i2h->old_file.path, index_delta2status(i2h->status), cbdata))
-				err = GIT_EUSER;
-		}
+		if ((err = git_diff__paired_foreach(
+				 idx2head, NULL, status_invoke_cb, &usercb)) < 0)
+			goto cleanup;
+
 		git_diff_list_free(idx2head);
 		idx2head = NULL;
 	}
 
-	i_max = idx2head ? idx2head->deltas.length : 0;
-	j_max = wd2idx   ? wd2idx->deltas.length   : 0;
-
-	if (idx2head && wd2idx &&
-		(0 != (idx2head->opts.flags & GIT_DIFF_DELTAS_ARE_ICASE) ||
-		 0 != (wd2idx->opts.flags & GIT_DIFF_DELTAS_ARE_ICASE)))
-	{
-		/* Then use the ignore-case sorter... */
-		ignore_case = true;
-
-		/* and assert that both are ignore-case sorted. If this function
-		 * ever needs to support merge joining result sets that are not sorted
-		 * by the same function, then it will need to be extended to do a spool
-		 * and sort on one of the results before merge joining */
-		assert(0 != (idx2head->opts.flags & GIT_DIFF_DELTAS_ARE_ICASE) &&
-			0 != (wd2idx->opts.flags & GIT_DIFF_DELTAS_ARE_ICASE));
-	}
-
-	for (i = 0, j = 0; !err && (i < i_max || j < j_max); ) {
-		i2h = idx2head ? GIT_VECTOR_GET(&idx2head->deltas,i) : NULL;
-		w2i = wd2idx   ? GIT_VECTOR_GET(&wd2idx->deltas,j)   : NULL;
-
-		cmp = !w2i ? -1 : !i2h ? 1 : STRCMP_CASESELECT(ignore_case, i2h->old_file.path, w2i->old_file.path);
-
-		if (cmp < 0) {
-			if (cb(i2h->old_file.path, index_delta2status(i2h->status), cbdata))
-				err = GIT_EUSER;
-			i++;
-		} else if (cmp > 0) {
-			if (cb(w2i->old_file.path, workdir_delta2status(w2i->status), cbdata))
-				err = GIT_EUSER;
-			j++;
-		} else {
-			if (cb(i2h->old_file.path, index_delta2status(i2h->status) |
-				   workdir_delta2status(w2i->status), cbdata))
-				err = GIT_EUSER;
-			i++; j++;
-		}
-	}
+	err = git_diff__paired_foreach(idx2head, wd2idx, status_invoke_cb, &usercb);
 
 cleanup:
 	git_tree_free(head);
diff --git a/src/submodule.c b/src/submodule.c
index d69559dc2..1364b6881 100644
--- a/src/submodule.c
+++ b/src/submodule.c
@@ -371,7 +371,7 @@ int git_submodule_add_to_index(git_submodule *sm, int write_index)
 
 	memset(&entry, 0, sizeof(entry));
 	entry.path = sm->path;
-	git_index__init_entry_from_stat(&st, &entry);
+	git_index_entry__init_from_stat(&entry, &st);
 
 	/* calling git_submodule_open will have set sm->wd_oid if possible */
 	if ((sm->flags & GIT_SUBMODULE_STATUS__WD_OID_VALID) == 0) {
diff --git a/src/transports/http.c b/src/transports/http.c
index 113c7edda..66cad619b 100644
--- a/src/transports/http.c
+++ b/src/transports/http.c
@@ -628,6 +628,8 @@ int git_smart_subtransport_http(git_smart_subtransport **out,
 {
 	http_subtransport *t;
 
+	(void)flags;
+
 	if (!out)
 		return -1;
 
diff --git a/src/util.h b/src/util.h
index 3d00e9c85..23d4bc6e9 100644
--- a/src/util.h
+++ b/src/util.h
@@ -81,6 +81,11 @@ extern int git__prefixcmp(const char *str, const char *prefix);
 extern int git__prefixcmp_icase(const char *str, const char *prefix);
 extern int git__suffixcmp(const char *str, const char *suffix);
 
+GIT_INLINE(int) git__signum(int val)
+{
+	return ((val > 0) - (val < 0));
+}
+
 extern int git__strtol32(int32_t *n, const char *buff, const char **end_buf, int base);
 extern int git__strtol64(int64_t *n, const char *buff, const char **end_buf, int base);