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-rw-r--r--third_party/git/builtin/checkout.c1868
1 files changed, 0 insertions, 1868 deletions
diff --git a/third_party/git/builtin/checkout.c b/third_party/git/builtin/checkout.c
deleted file mode 100644
index 0951f8fee5cc..000000000000
--- a/third_party/git/builtin/checkout.c
+++ /dev/null
@@ -1,1868 +0,0 @@
-#define USE_THE_INDEX_COMPATIBILITY_MACROS
-#include "builtin.h"
-#include "advice.h"
-#include "blob.h"
-#include "branch.h"
-#include "cache-tree.h"
-#include "checkout.h"
-#include "commit.h"
-#include "config.h"
-#include "diff.h"
-#include "dir.h"
-#include "ll-merge.h"
-#include "lockfile.h"
-#include "merge-recursive.h"
-#include "object-store.h"
-#include "parse-options.h"
-#include "refs.h"
-#include "remote.h"
-#include "resolve-undo.h"
-#include "revision.h"
-#include "run-command.h"
-#include "submodule.h"
-#include "submodule-config.h"
-#include "tree.h"
-#include "tree-walk.h"
-#include "unpack-trees.h"
-#include "wt-status.h"
-#include "xdiff-interface.h"
-
-static const char * const checkout_usage[] = {
-	N_("git checkout [<options>] <branch>"),
-	N_("git checkout [<options>] [<branch>] -- <file>..."),
-	NULL,
-};
-
-static const char * const switch_branch_usage[] = {
-	N_("git switch [<options>] [<branch>]"),
-	NULL,
-};
-
-static const char * const restore_usage[] = {
-	N_("git restore [<options>] [--source=<branch>] <file>..."),
-	NULL,
-};
-
-struct checkout_opts {
-	int patch_mode;
-	int quiet;
-	int merge;
-	int force;
-	int force_detach;
-	int implicit_detach;
-	int writeout_stage;
-	int overwrite_ignore;
-	int ignore_skipworktree;
-	int ignore_other_worktrees;
-	int show_progress;
-	int count_checkout_paths;
-	int overlay_mode;
-	int dwim_new_local_branch;
-	int discard_changes;
-	int accept_ref;
-	int accept_pathspec;
-	int switch_branch_doing_nothing_is_ok;
-	int only_merge_on_switching_branches;
-	int can_switch_when_in_progress;
-	int orphan_from_empty_tree;
-	int empty_pathspec_ok;
-	int checkout_index;
-	int checkout_worktree;
-	const char *ignore_unmerged_opt;
-	int ignore_unmerged;
-	int pathspec_file_nul;
-	const char *pathspec_from_file;
-
-	const char *new_branch;
-	const char *new_branch_force;
-	const char *new_orphan_branch;
-	int new_branch_log;
-	enum branch_track track;
-	struct diff_options diff_options;
-	char *conflict_style;
-
-	int branch_exists;
-	const char *prefix;
-	struct pathspec pathspec;
-	const char *from_treeish;
-	struct tree *source_tree;
-};
-
-struct branch_info {
-	const char *name; /* The short name used */
-	const char *path; /* The full name of a real branch */
-	struct commit *commit; /* The named commit */
-	char *refname; /* The full name of the ref being checked out. */
-	struct object_id oid; /* The object ID of the commit being checked out. */
-	/*
-	 * if not null the branch is detached because it's already
-	 * checked out in this checkout
-	 */
-	char *checkout;
-};
-
-static int post_checkout_hook(struct commit *old_commit, struct commit *new_commit,
-			      int changed)
-{
-	return run_hook_le(NULL, "post-checkout",
-			   oid_to_hex(old_commit ? &old_commit->object.oid : &null_oid),
-			   oid_to_hex(new_commit ? &new_commit->object.oid : &null_oid),
-			   changed ? "1" : "0", NULL);
-	/* "new_commit" can be NULL when checking out from the index before
-	   a commit exists. */
-
-}
-
-static int update_some(const struct object_id *oid, struct strbuf *base,
-		const char *pathname, unsigned mode, int stage, void *context)
-{
-	int len;
-	struct cache_entry *ce;
-	int pos;
-
-	if (S_ISDIR(mode))
-		return READ_TREE_RECURSIVE;
-
-	len = base->len + strlen(pathname);
-	ce = make_empty_cache_entry(&the_index, len);
-	oidcpy(&ce->oid, oid);
-	memcpy(ce->name, base->buf, base->len);
-	memcpy(ce->name + base->len, pathname, len - base->len);
-	ce->ce_flags = create_ce_flags(0) | CE_UPDATE;
-	ce->ce_namelen = len;
-	ce->ce_mode = create_ce_mode(mode);
-
-	/*
-	 * If the entry is the same as the current index, we can leave the old
-	 * entry in place. Whether it is UPTODATE or not, checkout_entry will
-	 * do the right thing.
-	 */
-	pos = cache_name_pos(ce->name, ce->ce_namelen);
-	if (pos >= 0) {
-		struct cache_entry *old = active_cache[pos];
-		if (ce->ce_mode == old->ce_mode &&
-		    !ce_intent_to_add(old) &&
-		    oideq(&ce->oid, &old->oid)) {
-			old->ce_flags |= CE_UPDATE;
-			discard_cache_entry(ce);
-			return 0;
-		}
-	}
-
-	add_cache_entry(ce, ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE);
-	return 0;
-}
-
-static int read_tree_some(struct tree *tree, const struct pathspec *pathspec)
-{
-	read_tree_recursive(the_repository, tree, "", 0, 0,
-			    pathspec, update_some, NULL);
-
-	/* update the index with the given tree's info
-	 * for all args, expanding wildcards, and exit
-	 * with any non-zero return code.
-	 */
-	return 0;
-}
-
-static int skip_same_name(const struct cache_entry *ce, int pos)
-{
-	while (++pos < active_nr &&
-	       !strcmp(active_cache[pos]->name, ce->name))
-		; /* skip */
-	return pos;
-}
-
-static int check_stage(int stage, const struct cache_entry *ce, int pos,
-		       int overlay_mode)
-{
-	while (pos < active_nr &&
-	       !strcmp(active_cache[pos]->name, ce->name)) {
-		if (ce_stage(active_cache[pos]) == stage)
-			return 0;
-		pos++;
-	}
-	if (!overlay_mode)
-		return 0;
-	if (stage == 2)
-		return error(_("path '%s' does not have our version"), ce->name);
-	else
-		return error(_("path '%s' does not have their version"), ce->name);
-}
-
-static int check_stages(unsigned stages, const struct cache_entry *ce, int pos)
-{
-	unsigned seen = 0;
-	const char *name = ce->name;
-
-	while (pos < active_nr) {
-		ce = active_cache[pos];
-		if (strcmp(name, ce->name))
-			break;
-		seen |= (1 << ce_stage(ce));
-		pos++;
-	}
-	if ((stages & seen) != stages)
-		return error(_("path '%s' does not have all necessary versions"),
-			     name);
-	return 0;
-}
-
-static int checkout_stage(int stage, const struct cache_entry *ce, int pos,
-			  const struct checkout *state, int *nr_checkouts,
-			  int overlay_mode)
-{
-	while (pos < active_nr &&
-	       !strcmp(active_cache[pos]->name, ce->name)) {
-		if (ce_stage(active_cache[pos]) == stage)
-			return checkout_entry(active_cache[pos], state,
-					      NULL, nr_checkouts);
-		pos++;
-	}
-	if (!overlay_mode) {
-		unlink_entry(ce);
-		return 0;
-	}
-	if (stage == 2)
-		return error(_("path '%s' does not have our version"), ce->name);
-	else
-		return error(_("path '%s' does not have their version"), ce->name);
-}
-
-static int checkout_merged(int pos, const struct checkout *state, int *nr_checkouts)
-{
-	struct cache_entry *ce = active_cache[pos];
-	const char *path = ce->name;
-	mmfile_t ancestor, ours, theirs;
-	int status;
-	struct object_id oid;
-	mmbuffer_t result_buf;
-	struct object_id threeway[3];
-	unsigned mode = 0;
-	struct ll_merge_options ll_opts;
-	int renormalize = 0;
-
-	memset(threeway, 0, sizeof(threeway));
-	while (pos < active_nr) {
-		int stage;
-		stage = ce_stage(ce);
-		if (!stage || strcmp(path, ce->name))
-			break;
-		oidcpy(&threeway[stage - 1], &ce->oid);
-		if (stage == 2)
-			mode = create_ce_mode(ce->ce_mode);
-		pos++;
-		ce = active_cache[pos];
-	}
-	if (is_null_oid(&threeway[1]) || is_null_oid(&threeway[2]))
-		return error(_("path '%s' does not have necessary versions"), path);
-
-	read_mmblob(&ancestor, &threeway[0]);
-	read_mmblob(&ours, &threeway[1]);
-	read_mmblob(&theirs, &threeway[2]);
-
-	memset(&ll_opts, 0, sizeof(ll_opts));
-	git_config_get_bool("merge.renormalize", &renormalize);
-	ll_opts.renormalize = renormalize;
-	status = ll_merge(&result_buf, path, &ancestor, "base",
-			  &ours, "ours", &theirs, "theirs",
-			  state->istate, &ll_opts);
-	free(ancestor.ptr);
-	free(ours.ptr);
-	free(theirs.ptr);
-	if (status < 0 || !result_buf.ptr) {
-		free(result_buf.ptr);
-		return error(_("path '%s': cannot merge"), path);
-	}
-
-	/*
-	 * NEEDSWORK:
-	 * There is absolutely no reason to write this as a blob object
-	 * and create a phony cache entry.  This hack is primarily to get
-	 * to the write_entry() machinery that massages the contents to
-	 * work-tree format and writes out which only allows it for a
-	 * cache entry.  The code in write_entry() needs to be refactored
-	 * to allow us to feed a <buffer, size, mode> instead of a cache
-	 * entry.  Such a refactoring would help merge_recursive as well
-	 * (it also writes the merge result to the object database even
-	 * when it may contain conflicts).
-	 */
-	if (write_object_file(result_buf.ptr, result_buf.size, blob_type, &oid))
-		die(_("Unable to add merge result for '%s'"), path);
-	free(result_buf.ptr);
-	ce = make_transient_cache_entry(mode, &oid, path, 2);
-	if (!ce)
-		die(_("make_cache_entry failed for path '%s'"), path);
-	status = checkout_entry(ce, state, NULL, nr_checkouts);
-	discard_cache_entry(ce);
-	return status;
-}
-
-static void mark_ce_for_checkout_overlay(struct cache_entry *ce,
-					 char *ps_matched,
-					 const struct checkout_opts *opts)
-{
-	ce->ce_flags &= ~CE_MATCHED;
-	if (!opts->ignore_skipworktree && ce_skip_worktree(ce))
-		return;
-	if (opts->source_tree && !(ce->ce_flags & CE_UPDATE))
-		/*
-		 * "git checkout tree-ish -- path", but this entry
-		 * is in the original index but is not in tree-ish
-		 * or does not match the pathspec; it will not be
-		 * checked out to the working tree.  We will not do
-		 * anything to this entry at all.
-		 */
-		return;
-	/*
-	 * Either this entry came from the tree-ish we are
-	 * checking the paths out of, or we are checking out
-	 * of the index.
-	 *
-	 * If it comes from the tree-ish, we already know it
-	 * matches the pathspec and could just stamp
-	 * CE_MATCHED to it from update_some(). But we still
-	 * need ps_matched and read_tree_recursive (and
-	 * eventually tree_entry_interesting) cannot fill
-	 * ps_matched yet. Once it can, we can avoid calling
-	 * match_pathspec() for _all_ entries when
-	 * opts->source_tree != NULL.
-	 */
-	if (ce_path_match(&the_index, ce, &opts->pathspec, ps_matched))
-		ce->ce_flags |= CE_MATCHED;
-}
-
-static void mark_ce_for_checkout_no_overlay(struct cache_entry *ce,
-					    char *ps_matched,
-					    const struct checkout_opts *opts)
-{
-	ce->ce_flags &= ~CE_MATCHED;
-	if (!opts->ignore_skipworktree && ce_skip_worktree(ce))
-		return;
-	if (ce_path_match(&the_index, ce, &opts->pathspec, ps_matched)) {
-		ce->ce_flags |= CE_MATCHED;
-		if (opts->source_tree && !(ce->ce_flags & CE_UPDATE))
-			/*
-			 * In overlay mode, but the path is not in
-			 * tree-ish, which means we should remove it
-			 * from the index and the working tree.
-			 */
-			ce->ce_flags |= CE_REMOVE | CE_WT_REMOVE;
-	}
-}
-
-static int checkout_worktree(const struct checkout_opts *opts,
-			     const struct branch_info *info)
-{
-	struct checkout state = CHECKOUT_INIT;
-	int nr_checkouts = 0, nr_unmerged = 0;
-	int errs = 0;
-	int pos;
-
-	state.force = 1;
-	state.refresh_cache = 1;
-	state.istate = &the_index;
-
-	init_checkout_metadata(&state.meta, info->refname,
-			       info->commit ? &info->commit->object.oid : &info->oid,
-			       NULL);
-
-	enable_delayed_checkout(&state);
-	for (pos = 0; pos < active_nr; pos++) {
-		struct cache_entry *ce = active_cache[pos];
-		if (ce->ce_flags & CE_MATCHED) {
-			if (!ce_stage(ce)) {
-				errs |= checkout_entry(ce, &state,
-						       NULL, &nr_checkouts);
-				continue;
-			}
-			if (opts->writeout_stage)
-				errs |= checkout_stage(opts->writeout_stage,
-						       ce, pos,
-						       &state,
-						       &nr_checkouts, opts->overlay_mode);
-			else if (opts->merge)
-				errs |= checkout_merged(pos, &state,
-							&nr_unmerged);
-			pos = skip_same_name(ce, pos) - 1;
-		}
-	}
-	remove_marked_cache_entries(&the_index, 1);
-	remove_scheduled_dirs();
-	errs |= finish_delayed_checkout(&state, &nr_checkouts);
-
-	if (opts->count_checkout_paths) {
-		if (nr_unmerged)
-			fprintf_ln(stderr, Q_("Recreated %d merge conflict",
-					      "Recreated %d merge conflicts",
-					      nr_unmerged),
-				   nr_unmerged);
-		if (opts->source_tree)
-			fprintf_ln(stderr, Q_("Updated %d path from %s",
-					      "Updated %d paths from %s",
-					      nr_checkouts),
-				   nr_checkouts,
-				   find_unique_abbrev(&opts->source_tree->object.oid,
-						      DEFAULT_ABBREV));
-		else if (!nr_unmerged || nr_checkouts)
-			fprintf_ln(stderr, Q_("Updated %d path from the index",
-					      "Updated %d paths from the index",
-					      nr_checkouts),
-				   nr_checkouts);
-	}
-
-	return errs;
-}
-
-static int checkout_paths(const struct checkout_opts *opts,
-			  const struct branch_info *new_branch_info)
-{
-	int pos;
-	static char *ps_matched;
-	struct object_id rev;
-	struct commit *head;
-	int errs = 0;
-	struct lock_file lock_file = LOCK_INIT;
-	int checkout_index;
-
-	trace2_cmd_mode(opts->patch_mode ? "patch" : "path");
-
-	if (opts->track != BRANCH_TRACK_UNSPECIFIED)
-		die(_("'%s' cannot be used with updating paths"), "--track");
-
-	if (opts->new_branch_log)
-		die(_("'%s' cannot be used with updating paths"), "-l");
-
-	if (opts->ignore_unmerged && opts->patch_mode)
-		die(_("'%s' cannot be used with updating paths"),
-		    opts->ignore_unmerged_opt);
-
-	if (opts->force_detach)
-		die(_("'%s' cannot be used with updating paths"), "--detach");
-
-	if (opts->merge && opts->patch_mode)
-		die(_("'%s' cannot be used with %s"), "--merge", "--patch");
-
-	if (opts->ignore_unmerged && opts->merge)
-		die(_("'%s' cannot be used with %s"),
-		    opts->ignore_unmerged_opt, "-m");
-
-	if (opts->new_branch)
-		die(_("Cannot update paths and switch to branch '%s' at the same time."),
-		    opts->new_branch);
-
-	if (!opts->checkout_worktree && !opts->checkout_index)
-		die(_("neither '%s' or '%s' is specified"),
-		    "--staged", "--worktree");
-
-	if (!opts->checkout_worktree && !opts->from_treeish)
-		die(_("'%s' must be used when '%s' is not specified"),
-		    "--worktree", "--source");
-
-	if (opts->checkout_index && !opts->checkout_worktree &&
-	    opts->writeout_stage)
-		die(_("'%s' or '%s' cannot be used with %s"),
-		    "--ours", "--theirs", "--staged");
-
-	if (opts->checkout_index && !opts->checkout_worktree &&
-	    opts->merge)
-		die(_("'%s' or '%s' cannot be used with %s"),
-		    "--merge", "--conflict", "--staged");
-
-	if (opts->patch_mode) {
-		const char *patch_mode;
-
-		if (opts->checkout_index && opts->checkout_worktree)
-			patch_mode = "--patch=checkout";
-		else if (opts->checkout_index && !opts->checkout_worktree)
-			patch_mode = "--patch=reset";
-		else if (!opts->checkout_index && opts->checkout_worktree)
-			patch_mode = "--patch=worktree";
-		else
-			BUG("either flag must have been set, worktree=%d, index=%d",
-			    opts->checkout_worktree, opts->checkout_index);
-		return run_add_interactive(new_branch_info->name, patch_mode, &opts->pathspec);
-	}
-
-	repo_hold_locked_index(the_repository, &lock_file, LOCK_DIE_ON_ERROR);
-	if (read_cache_preload(&opts->pathspec) < 0)
-		return error(_("index file corrupt"));
-
-	if (opts->source_tree)
-		read_tree_some(opts->source_tree, &opts->pathspec);
-
-	ps_matched = xcalloc(opts->pathspec.nr, 1);
-
-	/*
-	 * Make sure all pathspecs participated in locating the paths
-	 * to be checked out.
-	 */
-	for (pos = 0; pos < active_nr; pos++)
-		if (opts->overlay_mode)
-			mark_ce_for_checkout_overlay(active_cache[pos],
-						     ps_matched,
-						     opts);
-		else
-			mark_ce_for_checkout_no_overlay(active_cache[pos],
-							ps_matched,
-							opts);
-
-	if (report_path_error(ps_matched, &opts->pathspec)) {
-		free(ps_matched);
-		return 1;
-	}
-	free(ps_matched);
-
-	/* "checkout -m path" to recreate conflicted state */
-	if (opts->merge)
-		unmerge_marked_index(&the_index);
-
-	/* Any unmerged paths? */
-	for (pos = 0; pos < active_nr; pos++) {
-		const struct cache_entry *ce = active_cache[pos];
-		if (ce->ce_flags & CE_MATCHED) {
-			if (!ce_stage(ce))
-				continue;
-			if (opts->ignore_unmerged) {
-				if (!opts->quiet)
-					warning(_("path '%s' is unmerged"), ce->name);
-			} else if (opts->writeout_stage) {
-				errs |= check_stage(opts->writeout_stage, ce, pos, opts->overlay_mode);
-			} else if (opts->merge) {
-				errs |= check_stages((1<<2) | (1<<3), ce, pos);
-			} else {
-				errs = 1;
-				error(_("path '%s' is unmerged"), ce->name);
-			}
-			pos = skip_same_name(ce, pos) - 1;
-		}
-	}
-	if (errs)
-		return 1;
-
-	/* Now we are committed to check them out */
-	if (opts->checkout_worktree)
-		errs |= checkout_worktree(opts, new_branch_info);
-	else
-		remove_marked_cache_entries(&the_index, 1);
-
-	/*
-	 * Allow updating the index when checking out from the index.
-	 * This is to save new stat info.
-	 */
-	if (opts->checkout_worktree && !opts->checkout_index && !opts->source_tree)
-		checkout_index = 1;
-	else
-		checkout_index = opts->checkout_index;
-
-	if (checkout_index) {
-		if (write_locked_index(&the_index, &lock_file, COMMIT_LOCK))
-			die(_("unable to write new index file"));
-	} else {
-		/*
-		 * NEEDSWORK: if --worktree is not specified, we
-		 * should save stat info of checked out files in the
-		 * index to avoid the next (potentially costly)
-		 * refresh. But it's a bit tricker to do...
-		 */
-		rollback_lock_file(&lock_file);
-	}
-
-	read_ref_full("HEAD", 0, &rev, NULL);
-	head = lookup_commit_reference_gently(the_repository, &rev, 1);
-
-	errs |= post_checkout_hook(head, head, 0);
-	return errs;
-}
-
-static void show_local_changes(struct object *head,
-			       const struct diff_options *opts)
-{
-	struct rev_info rev;
-	/* I think we want full paths, even if we're in a subdirectory. */
-	repo_init_revisions(the_repository, &rev, NULL);
-	rev.diffopt.flags = opts->flags;
-	rev.diffopt.output_format |= DIFF_FORMAT_NAME_STATUS;
-	diff_setup_done(&rev.diffopt);
-	add_pending_object(&rev, head, NULL);
-	run_diff_index(&rev, 0);
-}
-
-static void describe_detached_head(const char *msg, struct commit *commit)
-{
-	struct strbuf sb = STRBUF_INIT;
-
-	if (!parse_commit(commit))
-		pp_commit_easy(CMIT_FMT_ONELINE, commit, &sb);
-	if (print_sha1_ellipsis()) {
-		fprintf(stderr, "%s %s... %s\n", msg,
-			find_unique_abbrev(&commit->object.oid, DEFAULT_ABBREV), sb.buf);
-	} else {
-		fprintf(stderr, "%s %s %s\n", msg,
-			find_unique_abbrev(&commit->object.oid, DEFAULT_ABBREV), sb.buf);
-	}
-	strbuf_release(&sb);
-}
-
-static int reset_tree(struct tree *tree, const struct checkout_opts *o,
-		      int worktree, int *writeout_error,
-		      struct branch_info *info)
-{
-	struct unpack_trees_options opts;
-	struct tree_desc tree_desc;
-
-	memset(&opts, 0, sizeof(opts));
-	opts.head_idx = -1;
-	opts.update = worktree;
-	opts.skip_unmerged = !worktree;
-	opts.reset = 1;
-	opts.merge = 1;
-	opts.fn = oneway_merge;
-	opts.verbose_update = o->show_progress;
-	opts.src_index = &the_index;
-	opts.dst_index = &the_index;
-	init_checkout_metadata(&opts.meta, info->refname,
-			       info->commit ? &info->commit->object.oid : &null_oid,
-			       NULL);
-	parse_tree(tree);
-	init_tree_desc(&tree_desc, tree->buffer, tree->size);
-	switch (unpack_trees(1, &tree_desc, &opts)) {
-	case -2:
-		*writeout_error = 1;
-		/*
-		 * We return 0 nevertheless, as the index is all right
-		 * and more importantly we have made best efforts to
-		 * update paths in the work tree, and we cannot revert
-		 * them.
-		 */
-		/* fallthrough */
-	case 0:
-		return 0;
-	default:
-		return 128;
-	}
-}
-
-static void setup_branch_path(struct branch_info *branch)
-{
-	struct strbuf buf = STRBUF_INIT;
-
-	/*
-	 * If this is a ref, resolve it; otherwise, look up the OID for our
-	 * expression.  Failure here is okay.
-	 */
-	if (!dwim_ref(branch->name, strlen(branch->name), &branch->oid, &branch->refname, 0))
-		repo_get_oid_committish(the_repository, branch->name, &branch->oid);
-
-	strbuf_branchname(&buf, branch->name, INTERPRET_BRANCH_LOCAL);
-	if (strcmp(buf.buf, branch->name))
-		branch->name = xstrdup(buf.buf);
-	strbuf_splice(&buf, 0, 0, "refs/heads/", 11);
-	branch->path = strbuf_detach(&buf, NULL);
-}
-
-static int merge_working_tree(const struct checkout_opts *opts,
-			      struct branch_info *old_branch_info,
-			      struct branch_info *new_branch_info,
-			      int *writeout_error)
-{
-	int ret;
-	struct lock_file lock_file = LOCK_INIT;
-	struct tree *new_tree;
-
-	hold_locked_index(&lock_file, LOCK_DIE_ON_ERROR);
-	if (read_cache_preload(NULL) < 0)
-		return error(_("index file corrupt"));
-
-	resolve_undo_clear();
-	if (opts->new_orphan_branch && opts->orphan_from_empty_tree) {
-		if (new_branch_info->commit)
-			BUG("'switch --orphan' should never accept a commit as starting point");
-		new_tree = parse_tree_indirect(the_hash_algo->empty_tree);
-	} else
-		new_tree = get_commit_tree(new_branch_info->commit);
-	if (opts->discard_changes) {
-		ret = reset_tree(new_tree, opts, 1, writeout_error, new_branch_info);
-		if (ret)
-			return ret;
-	} else {
-		struct tree_desc trees[2];
-		struct tree *tree;
-		struct unpack_trees_options topts;
-
-		memset(&topts, 0, sizeof(topts));
-		topts.head_idx = -1;
-		topts.src_index = &the_index;
-		topts.dst_index = &the_index;
-
-		setup_unpack_trees_porcelain(&topts, "checkout");
-
-		refresh_cache(REFRESH_QUIET);
-
-		if (unmerged_cache()) {
-			error(_("you need to resolve your current index first"));
-			return 1;
-		}
-
-		/* 2-way merge to the new branch */
-		topts.initial_checkout = is_cache_unborn();
-		topts.update = 1;
-		topts.merge = 1;
-		topts.quiet = opts->merge && old_branch_info->commit;
-		topts.verbose_update = opts->show_progress;
-		topts.fn = twoway_merge;
-		init_checkout_metadata(&topts.meta, new_branch_info->refname,
-				       new_branch_info->commit ?
-				       &new_branch_info->commit->object.oid :
-				       &new_branch_info->oid, NULL);
-		if (opts->overwrite_ignore) {
-			topts.dir = xcalloc(1, sizeof(*topts.dir));
-			topts.dir->flags |= DIR_SHOW_IGNORED;
-			setup_standard_excludes(topts.dir);
-		}
-		tree = parse_tree_indirect(old_branch_info->commit ?
-					   &old_branch_info->commit->object.oid :
-					   the_hash_algo->empty_tree);
-		init_tree_desc(&trees[0], tree->buffer, tree->size);
-		parse_tree(new_tree);
-		tree = new_tree;
-		init_tree_desc(&trees[1], tree->buffer, tree->size);
-
-		ret = unpack_trees(2, trees, &topts);
-		clear_unpack_trees_porcelain(&topts);
-		if (ret == -1) {
-			/*
-			 * Unpack couldn't do a trivial merge; either
-			 * give up or do a real merge, depending on
-			 * whether the merge flag was used.
-			 */
-			struct tree *work;
-			struct tree *old_tree;
-			struct merge_options o;
-			struct strbuf sb = STRBUF_INIT;
-			struct strbuf old_commit_shortname = STRBUF_INIT;
-
-			if (!opts->merge)
-				return 1;
-
-			/*
-			 * Without old_branch_info->commit, the below is the same as
-			 * the two-tree unpack we already tried and failed.
-			 */
-			if (!old_branch_info->commit)
-				return 1;
-			old_tree = get_commit_tree(old_branch_info->commit);
-
-			if (repo_index_has_changes(the_repository, old_tree, &sb))
-				die(_("cannot continue with staged changes in "
-				      "the following files:\n%s"), sb.buf);
-			strbuf_release(&sb);
-
-			/* Do more real merge */
-
-			/*
-			 * We update the index fully, then write the
-			 * tree from the index, then merge the new
-			 * branch with the current tree, with the old
-			 * branch as the base. Then we reset the index
-			 * (but not the working tree) to the new
-			 * branch, leaving the working tree as the
-			 * merged version, but skipping unmerged
-			 * entries in the index.
-			 */
-
-			add_files_to_cache(NULL, NULL, 0);
-			init_merge_options(&o, the_repository);
-			o.verbosity = 0;
-			work = write_in_core_index_as_tree(the_repository);
-
-			ret = reset_tree(new_tree,
-					 opts, 1,
-					 writeout_error, new_branch_info);
-			if (ret)
-				return ret;
-			o.ancestor = old_branch_info->name;
-			if (old_branch_info->name == NULL) {
-				strbuf_add_unique_abbrev(&old_commit_shortname,
-							 &old_branch_info->commit->object.oid,
-							 DEFAULT_ABBREV);
-				o.ancestor = old_commit_shortname.buf;
-			}
-			o.branch1 = new_branch_info->name;
-			o.branch2 = "local";
-			ret = merge_trees(&o,
-					  new_tree,
-					  work,
-					  old_tree);
-			if (ret < 0)
-				exit(128);
-			ret = reset_tree(new_tree,
-					 opts, 0,
-					 writeout_error, new_branch_info);
-			strbuf_release(&o.obuf);
-			strbuf_release(&old_commit_shortname);
-			if (ret)
-				return ret;
-		}
-	}
-
-	if (!active_cache_tree)
-		active_cache_tree = cache_tree();
-
-	if (!cache_tree_fully_valid(active_cache_tree))
-		cache_tree_update(&the_index, WRITE_TREE_SILENT | WRITE_TREE_REPAIR);
-
-	if (write_locked_index(&the_index, &lock_file, COMMIT_LOCK))
-		die(_("unable to write new index file"));
-
-	if (!opts->discard_changes && !opts->quiet && new_branch_info->commit)
-		show_local_changes(&new_branch_info->commit->object, &opts->diff_options);
-
-	return 0;
-}
-
-static void report_tracking(struct branch_info *new_branch_info)
-{
-	struct strbuf sb = STRBUF_INIT;
-	struct branch *branch = branch_get(new_branch_info->name);
-
-	if (!format_tracking_info(branch, &sb, AHEAD_BEHIND_FULL))
-		return;
-	fputs(sb.buf, stdout);
-	strbuf_release(&sb);
-}
-
-static void update_refs_for_switch(const struct checkout_opts *opts,
-				   struct branch_info *old_branch_info,
-				   struct branch_info *new_branch_info)
-{
-	struct strbuf msg = STRBUF_INIT;
-	const char *old_desc, *reflog_msg;
-	if (opts->new_branch) {
-		if (opts->new_orphan_branch) {
-			char *refname;
-
-			refname = mkpathdup("refs/heads/%s", opts->new_orphan_branch);
-			if (opts->new_branch_log &&
-			    !should_autocreate_reflog(refname)) {
-				int ret;
-				struct strbuf err = STRBUF_INIT;
-
-				ret = safe_create_reflog(refname, 1, &err);
-				if (ret) {
-					fprintf(stderr, _("Can not do reflog for '%s': %s\n"),
-						opts->new_orphan_branch, err.buf);
-					strbuf_release(&err);
-					free(refname);
-					return;
-				}
-				strbuf_release(&err);
-			}
-			free(refname);
-		}
-		else
-			create_branch(the_repository,
-				      opts->new_branch, new_branch_info->name,
-				      opts->new_branch_force ? 1 : 0,
-				      opts->new_branch_force ? 1 : 0,
-				      opts->new_branch_log,
-				      opts->quiet,
-				      opts->track);
-		new_branch_info->name = opts->new_branch;
-		setup_branch_path(new_branch_info);
-	}
-
-	old_desc = old_branch_info->name;
-	if (!old_desc && old_branch_info->commit)
-		old_desc = oid_to_hex(&old_branch_info->commit->object.oid);
-
-	reflog_msg = getenv("GIT_REFLOG_ACTION");
-	if (!reflog_msg)
-		strbuf_addf(&msg, "checkout: moving from %s to %s",
-			old_desc ? old_desc : "(invalid)", new_branch_info->name);
-	else
-		strbuf_insertstr(&msg, 0, reflog_msg);
-
-	if (!strcmp(new_branch_info->name, "HEAD") && !new_branch_info->path && !opts->force_detach) {
-		/* Nothing to do. */
-	} else if (opts->force_detach || !new_branch_info->path) {	/* No longer on any branch. */
-		update_ref(msg.buf, "HEAD", &new_branch_info->commit->object.oid, NULL,
-			   REF_NO_DEREF, UPDATE_REFS_DIE_ON_ERR);
-		if (!opts->quiet) {
-			if (old_branch_info->path &&
-			    advice_detached_head && !opts->force_detach)
-				detach_advice(new_branch_info->name);
-			describe_detached_head(_("HEAD is now at"), new_branch_info->commit);
-		}
-	} else if (new_branch_info->path) {	/* Switch branches. */
-		if (create_symref("HEAD", new_branch_info->path, msg.buf) < 0)
-			die(_("unable to update HEAD"));
-		if (!opts->quiet) {
-			if (old_branch_info->path && !strcmp(new_branch_info->path, old_branch_info->path)) {
-				if (opts->new_branch_force)
-					fprintf(stderr, _("Reset branch '%s'\n"),
-						new_branch_info->name);
-				else
-					fprintf(stderr, _("Already on '%s'\n"),
-						new_branch_info->name);
-			} else if (opts->new_branch) {
-				if (opts->branch_exists)
-					fprintf(stderr, _("Switched to and reset branch '%s'\n"), new_branch_info->name);
-				else
-					fprintf(stderr, _("Switched to a new branch '%s'\n"), new_branch_info->name);
-			} else {
-				fprintf(stderr, _("Switched to branch '%s'\n"),
-					new_branch_info->name);
-			}
-		}
-		if (old_branch_info->path && old_branch_info->name) {
-			if (!ref_exists(old_branch_info->path) && reflog_exists(old_branch_info->path))
-				delete_reflog(old_branch_info->path);
-		}
-	}
-	remove_branch_state(the_repository, !opts->quiet);
-	strbuf_release(&msg);
-	if (!opts->quiet &&
-	    (new_branch_info->path || (!opts->force_detach && !strcmp(new_branch_info->name, "HEAD"))))
-		report_tracking(new_branch_info);
-}
-
-static int add_pending_uninteresting_ref(const char *refname,
-					 const struct object_id *oid,
-					 int flags, void *cb_data)
-{
-	add_pending_oid(cb_data, refname, oid, UNINTERESTING);
-	return 0;
-}
-
-static void describe_one_orphan(struct strbuf *sb, struct commit *commit)
-{
-	strbuf_addstr(sb, "  ");
-	strbuf_add_unique_abbrev(sb, &commit->object.oid, DEFAULT_ABBREV);
-	strbuf_addch(sb, ' ');
-	if (!parse_commit(commit))
-		pp_commit_easy(CMIT_FMT_ONELINE, commit, sb);
-	strbuf_addch(sb, '\n');
-}
-
-#define ORPHAN_CUTOFF 4
-static void suggest_reattach(struct commit *commit, struct rev_info *revs)
-{
-	struct commit *c, *last = NULL;
-	struct strbuf sb = STRBUF_INIT;
-	int lost = 0;
-	while ((c = get_revision(revs)) != NULL) {
-		if (lost < ORPHAN_CUTOFF)
-			describe_one_orphan(&sb, c);
-		last = c;
-		lost++;
-	}
-	if (ORPHAN_CUTOFF < lost) {
-		int more = lost - ORPHAN_CUTOFF;
-		if (more == 1)
-			describe_one_orphan(&sb, last);
-		else
-			strbuf_addf(&sb, _(" ... and %d more.\n"), more);
-	}
-
-	fprintf(stderr,
-		Q_(
-		/* The singular version */
-		"Warning: you are leaving %d commit behind, "
-		"not connected to\n"
-		"any of your branches:\n\n"
-		"%s\n",
-		/* The plural version */
-		"Warning: you are leaving %d commits behind, "
-		"not connected to\n"
-		"any of your branches:\n\n"
-		"%s\n",
-		/* Give ngettext() the count */
-		lost),
-		lost,
-		sb.buf);
-	strbuf_release(&sb);
-
-	if (advice_detached_head)
-		fprintf(stderr,
-			Q_(
-			/* The singular version */
-			"If you want to keep it by creating a new branch, "
-			"this may be a good time\nto do so with:\n\n"
-			" git branch <new-branch-name> %s\n\n",
-			/* The plural version */
-			"If you want to keep them by creating a new branch, "
-			"this may be a good time\nto do so with:\n\n"
-			" git branch <new-branch-name> %s\n\n",
-			/* Give ngettext() the count */
-			lost),
-			find_unique_abbrev(&commit->object.oid, DEFAULT_ABBREV));
-}
-
-/*
- * We are about to leave commit that was at the tip of a detached
- * HEAD.  If it is not reachable from any ref, this is the last chance
- * for the user to do so without resorting to reflog.
- */
-static void orphaned_commit_warning(struct commit *old_commit, struct commit *new_commit)
-{
-	struct rev_info revs;
-	struct object *object = &old_commit->object;
-
-	repo_init_revisions(the_repository, &revs, NULL);
-	setup_revisions(0, NULL, &revs, NULL);
-
-	object->flags &= ~UNINTERESTING;
-	add_pending_object(&revs, object, oid_to_hex(&object->oid));
-
-	for_each_ref(add_pending_uninteresting_ref, &revs);
-	if (new_commit)
-		add_pending_oid(&revs, "HEAD",
-				&new_commit->object.oid,
-				UNINTERESTING);
-
-	if (prepare_revision_walk(&revs))
-		die(_("internal error in revision walk"));
-	if (!(old_commit->object.flags & UNINTERESTING))
-		suggest_reattach(old_commit, &revs);
-	else
-		describe_detached_head(_("Previous HEAD position was"), old_commit);
-
-	/* Clean up objects used, as they will be reused. */
-	clear_commit_marks_all(ALL_REV_FLAGS);
-}
-
-static int switch_branches(const struct checkout_opts *opts,
-			   struct branch_info *new_branch_info)
-{
-	int ret = 0;
-	struct branch_info old_branch_info;
-	void *path_to_free;
-	struct object_id rev;
-	int flag, writeout_error = 0;
-	int do_merge = 1;
-
-	trace2_cmd_mode("branch");
-
-	memset(&old_branch_info, 0, sizeof(old_branch_info));
-	old_branch_info.path = path_to_free = resolve_refdup("HEAD", 0, &rev, &flag);
-	if (old_branch_info.path)
-		old_branch_info.commit = lookup_commit_reference_gently(the_repository, &rev, 1);
-	if (!(flag & REF_ISSYMREF))
-		old_branch_info.path = NULL;
-
-	if (old_branch_info.path)
-		skip_prefix(old_branch_info.path, "refs/heads/", &old_branch_info.name);
-
-	if (opts->new_orphan_branch && opts->orphan_from_empty_tree) {
-		if (new_branch_info->name)
-			BUG("'switch --orphan' should never accept a commit as starting point");
-		new_branch_info->commit = NULL;
-		new_branch_info->name = "(empty)";
-		do_merge = 1;
-	}
-
-	if (!new_branch_info->name) {
-		new_branch_info->name = "HEAD";
-		new_branch_info->commit = old_branch_info.commit;
-		if (!new_branch_info->commit)
-			die(_("You are on a branch yet to be born"));
-		parse_commit_or_die(new_branch_info->commit);
-
-		if (opts->only_merge_on_switching_branches)
-			do_merge = 0;
-	}
-
-	if (do_merge) {
-		ret = merge_working_tree(opts, &old_branch_info, new_branch_info, &writeout_error);
-		if (ret) {
-			free(path_to_free);
-			return ret;
-		}
-	}
-
-	if (!opts->quiet && !old_branch_info.path && old_branch_info.commit && new_branch_info->commit != old_branch_info.commit)
-		orphaned_commit_warning(old_branch_info.commit, new_branch_info->commit);
-
-	update_refs_for_switch(opts, &old_branch_info, new_branch_info);
-
-	ret = post_checkout_hook(old_branch_info.commit, new_branch_info->commit, 1);
-	free(path_to_free);
-	return ret || writeout_error;
-}
-
-static int git_checkout_config(const char *var, const char *value, void *cb)
-{
-	if (!strcmp(var, "diff.ignoresubmodules")) {
-		struct checkout_opts *opts = cb;
-		handle_ignore_submodules_arg(&opts->diff_options, value);
-		return 0;
-	}
-
-	if (starts_with(var, "submodule."))
-		return git_default_submodule_config(var, value, NULL);
-
-	return git_xmerge_config(var, value, NULL);
-}
-
-static void setup_new_branch_info_and_source_tree(
-	struct branch_info *new_branch_info,
-	struct checkout_opts *opts,
-	struct object_id *rev,
-	const char *arg)
-{
-	struct tree **source_tree = &opts->source_tree;
-	struct object_id branch_rev;
-
-	new_branch_info->name = arg;
-	setup_branch_path(new_branch_info);
-
-	if (!check_refname_format(new_branch_info->path, 0) &&
-	    !read_ref(new_branch_info->path, &branch_rev))
-		oidcpy(rev, &branch_rev);
-	else {
-		free((char *)new_branch_info->path);
-		new_branch_info->path = NULL; /* not an existing branch */
-	}
-
-	new_branch_info->commit = lookup_commit_reference_gently(the_repository, rev, 1);
-	if (!new_branch_info->commit) {
-		/* not a commit */
-		*source_tree = parse_tree_indirect(rev);
-	} else {
-		parse_commit_or_die(new_branch_info->commit);
-		*source_tree = get_commit_tree(new_branch_info->commit);
-	}
-}
-
-static const char *parse_remote_branch(const char *arg,
-				       struct object_id *rev,
-				       int could_be_checkout_paths)
-{
-	int num_matches = 0;
-	const char *remote = unique_tracking_name(arg, rev, &num_matches);
-
-	if (remote && could_be_checkout_paths) {
-		die(_("'%s' could be both a local file and a tracking branch.\n"
-			"Please use -- (and optionally --no-guess) to disambiguate"),
-		    arg);
-	}
-
-	if (!remote && num_matches > 1) {
-	    if (advice_checkout_ambiguous_remote_branch_name) {
-		    advise(_("If you meant to check out a remote tracking branch on, e.g. 'origin',\n"
-			     "you can do so by fully qualifying the name with the --track option:\n"
-			     "\n"
-			     "    git checkout --track origin/<name>\n"
-			     "\n"
-			     "If you'd like to always have checkouts of an ambiguous <name> prefer\n"
-			     "one remote, e.g. the 'origin' remote, consider setting\n"
-			     "checkout.defaultRemote=origin in your config."));
-	    }
-
-	    die(_("'%s' matched multiple (%d) remote tracking branches"),
-		arg, num_matches);
-	}
-
-	return remote;
-}
-
-static int parse_branchname_arg(int argc, const char **argv,
-				int dwim_new_local_branch_ok,
-				struct branch_info *new_branch_info,
-				struct checkout_opts *opts,
-				struct object_id *rev)
-{
-	const char **new_branch = &opts->new_branch;
-	int argcount = 0;
-	const char *arg;
-	int dash_dash_pos;
-	int has_dash_dash = 0;
-	int i;
-
-	/*
-	 * case 1: git checkout <ref> -- [<paths>]
-	 *
-	 *   <ref> must be a valid tree, everything after the '--' must be
-	 *   a path.
-	 *
-	 * case 2: git checkout -- [<paths>]
-	 *
-	 *   everything after the '--' must be paths.
-	 *
-	 * case 3: git checkout <something> [--]
-	 *
-	 *   (a) If <something> is a commit, that is to
-	 *       switch to the branch or detach HEAD at it.  As a special case,
-	 *       if <something> is A...B (missing A or B means HEAD but you can
-	 *       omit at most one side), and if there is a unique merge base
-	 *       between A and B, A...B names that merge base.
-	 *
-	 *   (b) If <something> is _not_ a commit, either "--" is present
-	 *       or <something> is not a path, no -t or -b was given, and
-	 *       and there is a tracking branch whose name is <something>
-	 *       in one and only one remote (or if the branch exists on the
-	 *       remote named in checkout.defaultRemote), then this is a
-	 *       short-hand to fork local <something> from that
-	 *       remote-tracking branch.
-	 *
-	 *   (c) Otherwise, if "--" is present, treat it like case (1).
-	 *
-	 *   (d) Otherwise :
-	 *       - if it's a reference, treat it like case (1)
-	 *       - else if it's a path, treat it like case (2)
-	 *       - else: fail.
-	 *
-	 * case 4: git checkout <something> <paths>
-	 *
-	 *   The first argument must not be ambiguous.
-	 *   - If it's *only* a reference, treat it like case (1).
-	 *   - If it's only a path, treat it like case (2).
-	 *   - else: fail.
-	 *
-	 */
-	if (!argc)
-		return 0;
-
-	if (!opts->accept_pathspec) {
-		if (argc > 1)
-			die(_("only one reference expected"));
-		has_dash_dash = 1; /* helps disambiguate */
-	}
-
-	arg = argv[0];
-	dash_dash_pos = -1;
-	for (i = 0; i < argc; i++) {
-		if (opts->accept_pathspec && !strcmp(argv[i], "--")) {
-			dash_dash_pos = i;
-			break;
-		}
-	}
-	if (dash_dash_pos == 0)
-		return 1; /* case (2) */
-	else if (dash_dash_pos == 1)
-		has_dash_dash = 1; /* case (3) or (1) */
-	else if (dash_dash_pos >= 2)
-		die(_("only one reference expected, %d given."), dash_dash_pos);
-	opts->count_checkout_paths = !opts->quiet && !has_dash_dash;
-
-	if (!strcmp(arg, "-"))
-		arg = "@{-1}";
-
-	if (get_oid_mb(arg, rev)) {
-		/*
-		 * Either case (3) or (4), with <something> not being
-		 * a commit, or an attempt to use case (1) with an
-		 * invalid ref.
-		 *
-		 * It's likely an error, but we need to find out if
-		 * we should auto-create the branch, case (3).(b).
-		 */
-		int recover_with_dwim = dwim_new_local_branch_ok;
-
-		int could_be_checkout_paths = !has_dash_dash &&
-			check_filename(opts->prefix, arg);
-
-		if (!has_dash_dash && !no_wildcard(arg))
-			recover_with_dwim = 0;
-
-		/*
-		 * Accept "git checkout foo", "git checkout foo --"
-		 * and "git switch foo" as candidates for dwim.
-		 */
-		if (!(argc == 1 && !has_dash_dash) &&
-		    !(argc == 2 && has_dash_dash) &&
-		    opts->accept_pathspec)
-			recover_with_dwim = 0;
-
-		if (recover_with_dwim) {
-			const char *remote = parse_remote_branch(arg, rev,
-								 could_be_checkout_paths);
-			if (remote) {
-				*new_branch = arg;
-				arg = remote;
-				/* DWIMmed to create local branch, case (3).(b) */
-			} else {
-				recover_with_dwim = 0;
-			}
-		}
-
-		if (!recover_with_dwim) {
-			if (has_dash_dash)
-				die(_("invalid reference: %s"), arg);
-			return argcount;
-		}
-	}
-
-	/* we can't end up being in (2) anymore, eat the argument */
-	argcount++;
-	argv++;
-	argc--;
-
-	setup_new_branch_info_and_source_tree(new_branch_info, opts, rev, arg);
-
-	if (!opts->source_tree)                   /* case (1): want a tree */
-		die(_("reference is not a tree: %s"), arg);
-
-	if (!has_dash_dash) {	/* case (3).(d) -> (1) */
-		/*
-		 * Do not complain the most common case
-		 *	git checkout branch
-		 * even if there happen to be a file called 'branch';
-		 * it would be extremely annoying.
-		 */
-		if (argc)
-			verify_non_filename(opts->prefix, arg);
-	} else if (opts->accept_pathspec) {
-		argcount++;
-		argv++;
-		argc--;
-	}
-
-	return argcount;
-}
-
-static int switch_unborn_to_new_branch(const struct checkout_opts *opts)
-{
-	int status;
-	struct strbuf branch_ref = STRBUF_INIT;
-
-	trace2_cmd_mode("unborn");
-
-	if (!opts->new_branch)
-		die(_("You are on a branch yet to be born"));
-	strbuf_addf(&branch_ref, "refs/heads/%s", opts->new_branch);
-	status = create_symref("HEAD", branch_ref.buf, "checkout -b");
-	strbuf_release(&branch_ref);
-	if (!opts->quiet)
-		fprintf(stderr, _("Switched to a new branch '%s'\n"),
-			opts->new_branch);
-	return status;
-}
-
-static void die_expecting_a_branch(const struct branch_info *branch_info)
-{
-	struct object_id oid;
-	char *to_free;
-
-	if (dwim_ref(branch_info->name, strlen(branch_info->name), &oid, &to_free, 0) == 1) {
-		const char *ref = to_free;
-
-		if (skip_prefix(ref, "refs/tags/", &ref))
-			die(_("a branch is expected, got tag '%s'"), ref);
-		if (skip_prefix(ref, "refs/remotes/", &ref))
-			die(_("a branch is expected, got remote branch '%s'"), ref);
-		die(_("a branch is expected, got '%s'"), ref);
-	}
-	if (branch_info->commit)
-		die(_("a branch is expected, got commit '%s'"), branch_info->name);
-	/*
-	 * This case should never happen because we already die() on
-	 * non-commit, but just in case.
-	 */
-	die(_("a branch is expected, got '%s'"), branch_info->name);
-}
-
-static void die_if_some_operation_in_progress(void)
-{
-	struct wt_status_state state;
-
-	memset(&state, 0, sizeof(state));
-	wt_status_get_state(the_repository, &state, 0);
-
-	if (state.merge_in_progress)
-		die(_("cannot switch branch while merging\n"
-		      "Consider \"git merge --quit\" "
-		      "or \"git worktree add\"."));
-	if (state.am_in_progress)
-		die(_("cannot switch branch in the middle of an am session\n"
-		      "Consider \"git am --quit\" "
-		      "or \"git worktree add\"."));
-	if (state.rebase_interactive_in_progress || state.rebase_in_progress)
-		die(_("cannot switch branch while rebasing\n"
-		      "Consider \"git rebase --quit\" "
-		      "or \"git worktree add\"."));
-	if (state.cherry_pick_in_progress)
-		die(_("cannot switch branch while cherry-picking\n"
-		      "Consider \"git cherry-pick --quit\" "
-		      "or \"git worktree add\"."));
-	if (state.revert_in_progress)
-		die(_("cannot switch branch while reverting\n"
-		      "Consider \"git revert --quit\" "
-		      "or \"git worktree add\"."));
-	if (state.bisect_in_progress)
-		warning(_("you are switching branch while bisecting"));
-}
-
-static int checkout_branch(struct checkout_opts *opts,
-			   struct branch_info *new_branch_info)
-{
-	if (opts->pathspec.nr)
-		die(_("paths cannot be used with switching branches"));
-
-	if (opts->patch_mode)
-		die(_("'%s' cannot be used with switching branches"),
-		    "--patch");
-
-	if (opts->overlay_mode != -1)
-		die(_("'%s' cannot be used with switching branches"),
-		    "--[no]-overlay");
-
-	if (opts->writeout_stage)
-		die(_("'%s' cannot be used with switching branches"),
-		    "--ours/--theirs");
-
-	if (opts->force && opts->merge)
-		die(_("'%s' cannot be used with '%s'"), "-f", "-m");
-
-	if (opts->discard_changes && opts->merge)
-		die(_("'%s' cannot be used with '%s'"), "--discard-changes", "--merge");
-
-	if (opts->force_detach && opts->new_branch)
-		die(_("'%s' cannot be used with '%s'"),
-		    "--detach", "-b/-B/--orphan");
-
-	if (opts->new_orphan_branch) {
-		if (opts->track != BRANCH_TRACK_UNSPECIFIED)
-			die(_("'%s' cannot be used with '%s'"), "--orphan", "-t");
-		if (opts->orphan_from_empty_tree && new_branch_info->name)
-			die(_("'%s' cannot take <start-point>"), "--orphan");
-	} else if (opts->force_detach) {
-		if (opts->track != BRANCH_TRACK_UNSPECIFIED)
-			die(_("'%s' cannot be used with '%s'"), "--detach", "-t");
-	} else if (opts->track == BRANCH_TRACK_UNSPECIFIED)
-		opts->track = git_branch_track;
-
-	if (new_branch_info->name && !new_branch_info->commit)
-		die(_("Cannot switch branch to a non-commit '%s'"),
-		    new_branch_info->name);
-
-	if (!opts->switch_branch_doing_nothing_is_ok &&
-	    !new_branch_info->name &&
-	    !opts->new_branch &&
-	    !opts->force_detach)
-		die(_("missing branch or commit argument"));
-
-	if (!opts->implicit_detach &&
-	    !opts->force_detach &&
-	    !opts->new_branch &&
-	    !opts->new_branch_force &&
-	    new_branch_info->name &&
-	    !new_branch_info->path)
-		die_expecting_a_branch(new_branch_info);
-
-	if (!opts->can_switch_when_in_progress)
-		die_if_some_operation_in_progress();
-
-	if (new_branch_info->path && !opts->force_detach && !opts->new_branch &&
-	    !opts->ignore_other_worktrees) {
-		int flag;
-		char *head_ref = resolve_refdup("HEAD", 0, NULL, &flag);
-		if (head_ref &&
-		    (!(flag & REF_ISSYMREF) || strcmp(head_ref, new_branch_info->path)))
-			die_if_checked_out(new_branch_info->path, 1);
-		free(head_ref);
-	}
-
-	if (!new_branch_info->commit && opts->new_branch) {
-		struct object_id rev;
-		int flag;
-
-		if (!read_ref_full("HEAD", 0, &rev, &flag) &&
-		    (flag & REF_ISSYMREF) && is_null_oid(&rev))
-			return switch_unborn_to_new_branch(opts);
-	}
-	return switch_branches(opts, new_branch_info);
-}
-
-static struct option *add_common_options(struct checkout_opts *opts,
-					 struct option *prevopts)
-{
-	struct option options[] = {
-		OPT__QUIET(&opts->quiet, N_("suppress progress reporting")),
-		OPT_CALLBACK_F(0, "recurse-submodules", NULL,
-			    "checkout", "control recursive updating of submodules",
-			    PARSE_OPT_OPTARG, option_parse_recurse_submodules_worktree_updater),
-		OPT_BOOL(0, "progress", &opts->show_progress, N_("force progress reporting")),
-		OPT_BOOL('m', "merge", &opts->merge, N_("perform a 3-way merge with the new branch")),
-		OPT_STRING(0, "conflict", &opts->conflict_style, N_("style"),
-			   N_("conflict style (merge or diff3)")),
-		OPT_END()
-	};
-	struct option *newopts = parse_options_concat(prevopts, options);
-	free(prevopts);
-	return newopts;
-}
-
-static struct option *add_common_switch_branch_options(
-	struct checkout_opts *opts, struct option *prevopts)
-{
-	struct option options[] = {
-		OPT_BOOL('d', "detach", &opts->force_detach, N_("detach HEAD at named commit")),
-		OPT_SET_INT('t', "track",  &opts->track, N_("set upstream info for new branch"),
-			BRANCH_TRACK_EXPLICIT),
-		OPT__FORCE(&opts->force, N_("force checkout (throw away local modifications)"),
-			   PARSE_OPT_NOCOMPLETE),
-		OPT_STRING(0, "orphan", &opts->new_orphan_branch, N_("new-branch"), N_("new unparented branch")),
-		OPT_BOOL_F(0, "overwrite-ignore", &opts->overwrite_ignore,
-			   N_("update ignored files (default)"),
-			   PARSE_OPT_NOCOMPLETE),
-		OPT_BOOL(0, "ignore-other-worktrees", &opts->ignore_other_worktrees,
-			 N_("do not check if another worktree is holding the given ref")),
-		OPT_END()
-	};
-	struct option *newopts = parse_options_concat(prevopts, options);
-	free(prevopts);
-	return newopts;
-}
-
-static struct option *add_checkout_path_options(struct checkout_opts *opts,
-						struct option *prevopts)
-{
-	struct option options[] = {
-		OPT_SET_INT_F('2', "ours", &opts->writeout_stage,
-			      N_("checkout our version for unmerged files"),
-			      2, PARSE_OPT_NONEG),
-		OPT_SET_INT_F('3', "theirs", &opts->writeout_stage,
-			      N_("checkout their version for unmerged files"),
-			      3, PARSE_OPT_NONEG),
-		OPT_BOOL('p', "patch", &opts->patch_mode, N_("select hunks interactively")),
-		OPT_BOOL(0, "ignore-skip-worktree-bits", &opts->ignore_skipworktree,
-			 N_("do not limit pathspecs to sparse entries only")),
-		OPT_PATHSPEC_FROM_FILE(&opts->pathspec_from_file),
-		OPT_PATHSPEC_FILE_NUL(&opts->pathspec_file_nul),
-		OPT_END()
-	};
-	struct option *newopts = parse_options_concat(prevopts, options);
-	free(prevopts);
-	return newopts;
-}
-
-/* create-branch option (either b or c) */
-static char cb_option = 'b';
-
-static int checkout_main(int argc, const char **argv, const char *prefix,
-			 struct checkout_opts *opts, struct option *options,
-			 const char * const usagestr[])
-{
-	struct branch_info new_branch_info;
-	int parseopt_flags = 0;
-
-	memset(&new_branch_info, 0, sizeof(new_branch_info));
-	opts->overwrite_ignore = 1;
-	opts->prefix = prefix;
-	opts->show_progress = -1;
-
-	git_config(git_checkout_config, opts);
-
-	opts->track = BRANCH_TRACK_UNSPECIFIED;
-
-	if (!opts->accept_pathspec && !opts->accept_ref)
-		BUG("make up your mind, you need to take _something_");
-	if (opts->accept_pathspec && opts->accept_ref)
-		parseopt_flags = PARSE_OPT_KEEP_DASHDASH;
-
-	argc = parse_options(argc, argv, prefix, options,
-			     usagestr, parseopt_flags);
-
-	if (opts->show_progress < 0) {
-		if (opts->quiet)
-			opts->show_progress = 0;
-		else
-			opts->show_progress = isatty(2);
-	}
-
-	if (opts->conflict_style) {
-		opts->merge = 1; /* implied */
-		git_xmerge_config("merge.conflictstyle", opts->conflict_style, NULL);
-	}
-	if (opts->force) {
-		opts->discard_changes = 1;
-		opts->ignore_unmerged_opt = "--force";
-		opts->ignore_unmerged = 1;
-	}
-
-	if ((!!opts->new_branch + !!opts->new_branch_force + !!opts->new_orphan_branch) > 1)
-		die(_("-%c, -%c and --orphan are mutually exclusive"),
-				cb_option, toupper(cb_option));
-
-	if (opts->overlay_mode == 1 && opts->patch_mode)
-		die(_("-p and --overlay are mutually exclusive"));
-
-	if (opts->checkout_index >= 0 || opts->checkout_worktree >= 0) {
-		if (opts->checkout_index < 0)
-			opts->checkout_index = 0;
-		if (opts->checkout_worktree < 0)
-			opts->checkout_worktree = 0;
-	} else {
-		if (opts->checkout_index < 0)
-			opts->checkout_index = -opts->checkout_index - 1;
-		if (opts->checkout_worktree < 0)
-			opts->checkout_worktree = -opts->checkout_worktree - 1;
-	}
-	if (opts->checkout_index < 0 || opts->checkout_worktree < 0)
-		BUG("these flags should be non-negative by now");
-	/*
-	 * convenient shortcut: "git restore --staged [--worktree]" equals
-	 * "git restore --staged [--worktree] --source HEAD"
-	 */
-	if (!opts->from_treeish && opts->checkout_index)
-		opts->from_treeish = "HEAD";
-
-	/*
-	 * From here on, new_branch will contain the branch to be checked out,
-	 * and new_branch_force and new_orphan_branch will tell us which one of
-	 * -b/-B/-c/-C/--orphan is being used.
-	 */
-	if (opts->new_branch_force)
-		opts->new_branch = opts->new_branch_force;
-
-	if (opts->new_orphan_branch)
-		opts->new_branch = opts->new_orphan_branch;
-
-	/* --track without -c/-C/-b/-B/--orphan should DWIM */
-	if (opts->track != BRANCH_TRACK_UNSPECIFIED && !opts->new_branch) {
-		const char *argv0 = argv[0];
-		if (!argc || !strcmp(argv0, "--"))
-			die(_("--track needs a branch name"));
-		skip_prefix(argv0, "refs/", &argv0);
-		skip_prefix(argv0, "remotes/", &argv0);
-		argv0 = strchr(argv0, '/');
-		if (!argv0 || !argv0[1])
-			die(_("missing branch name; try -%c"), cb_option);
-		opts->new_branch = argv0 + 1;
-	}
-
-	/*
-	 * Extract branch name from command line arguments, so
-	 * all that is left is pathspecs.
-	 *
-	 * Handle
-	 *
-	 *  1) git checkout <tree> -- [<paths>]
-	 *  2) git checkout -- [<paths>]
-	 *  3) git checkout <something> [<paths>]
-	 *
-	 * including "last branch" syntax and DWIM-ery for names of
-	 * remote branches, erroring out for invalid or ambiguous cases.
-	 */
-	if (argc && opts->accept_ref) {
-		struct object_id rev;
-		int dwim_ok =
-			!opts->patch_mode &&
-			opts->dwim_new_local_branch &&
-			opts->track == BRANCH_TRACK_UNSPECIFIED &&
-			!opts->new_branch;
-		int n = parse_branchname_arg(argc, argv, dwim_ok,
-					     &new_branch_info, opts, &rev);
-		argv += n;
-		argc -= n;
-	} else if (!opts->accept_ref && opts->from_treeish) {
-		struct object_id rev;
-
-		if (get_oid_mb(opts->from_treeish, &rev))
-			die(_("could not resolve %s"), opts->from_treeish);
-
-		setup_new_branch_info_and_source_tree(&new_branch_info,
-						      opts, &rev,
-						      opts->from_treeish);
-
-		if (!opts->source_tree)
-			die(_("reference is not a tree: %s"), opts->from_treeish);
-	}
-
-	if (argc) {
-		parse_pathspec(&opts->pathspec, 0,
-			       opts->patch_mode ? PATHSPEC_PREFIX_ORIGIN : 0,
-			       prefix, argv);
-
-		if (!opts->pathspec.nr)
-			die(_("invalid path specification"));
-
-		/*
-		 * Try to give more helpful suggestion.
-		 * new_branch && argc > 1 will be caught later.
-		 */
-		if (opts->new_branch && argc == 1 && !new_branch_info.commit)
-			die(_("'%s' is not a commit and a branch '%s' cannot be created from it"),
-				argv[0], opts->new_branch);
-
-		if (opts->force_detach)
-			die(_("git checkout: --detach does not take a path argument '%s'"),
-			    argv[0]);
-	}
-
-	if (opts->pathspec_from_file) {
-		if (opts->pathspec.nr)
-			die(_("--pathspec-from-file is incompatible with pathspec arguments"));
-
-		if (opts->force_detach)
-			die(_("--pathspec-from-file is incompatible with --detach"));
-
-		if (opts->patch_mode)
-			die(_("--pathspec-from-file is incompatible with --patch"));
-
-		parse_pathspec_file(&opts->pathspec, 0,
-				    0,
-				    prefix, opts->pathspec_from_file, opts->pathspec_file_nul);
-	} else if (opts->pathspec_file_nul) {
-		die(_("--pathspec-file-nul requires --pathspec-from-file"));
-	}
-
-	opts->pathspec.recursive = 1;
-
-	if (opts->pathspec.nr) {
-		if (1 < !!opts->writeout_stage + !!opts->force + !!opts->merge)
-			die(_("git checkout: --ours/--theirs, --force and --merge are incompatible when\n"
-			      "checking out of the index."));
-	} else {
-		if (opts->accept_pathspec && !opts->empty_pathspec_ok &&
-		    !opts->patch_mode)	/* patch mode is special */
-			die(_("you must specify path(s) to restore"));
-	}
-
-	if (opts->new_branch) {
-		struct strbuf buf = STRBUF_INIT;
-
-		if (opts->new_branch_force)
-			opts->branch_exists = validate_branchname(opts->new_branch, &buf);
-		else
-			opts->branch_exists =
-				validate_new_branchname(opts->new_branch, &buf, 0);
-		strbuf_release(&buf);
-	}
-
-	UNLEAK(opts);
-	if (opts->patch_mode || opts->pathspec.nr)
-		return checkout_paths(opts, &new_branch_info);
-	else
-		return checkout_branch(opts, &new_branch_info);
-}
-
-int cmd_checkout(int argc, const char **argv, const char *prefix)
-{
-	struct checkout_opts opts;
-	struct option *options;
-	struct option checkout_options[] = {
-		OPT_STRING('b', NULL, &opts.new_branch, N_("branch"),
-			   N_("create and checkout a new branch")),
-		OPT_STRING('B', NULL, &opts.new_branch_force, N_("branch"),
-			   N_("create/reset and checkout a branch")),
-		OPT_BOOL('l', NULL, &opts.new_branch_log, N_("create reflog for new branch")),
-		OPT_BOOL(0, "guess", &opts.dwim_new_local_branch,
-			 N_("second guess 'git checkout <no-such-branch>' (default)")),
-		OPT_BOOL(0, "overlay", &opts.overlay_mode, N_("use overlay mode (default)")),
-		OPT_END()
-	};
-	int ret;
-
-	memset(&opts, 0, sizeof(opts));
-	opts.dwim_new_local_branch = 1;
-	opts.switch_branch_doing_nothing_is_ok = 1;
-	opts.only_merge_on_switching_branches = 0;
-	opts.accept_ref = 1;
-	opts.accept_pathspec = 1;
-	opts.implicit_detach = 1;
-	opts.can_switch_when_in_progress = 1;
-	opts.orphan_from_empty_tree = 0;
-	opts.empty_pathspec_ok = 1;
-	opts.overlay_mode = -1;
-	opts.checkout_index = -2;    /* default on */
-	opts.checkout_worktree = -2; /* default on */
-
-	if (argc == 3 && !strcmp(argv[1], "-b")) {
-		/*
-		 * User ran 'git checkout -b <branch>' and expects
-		 * the same behavior as 'git switch -c <branch>'.
-		 */
-		opts.switch_branch_doing_nothing_is_ok = 0;
-		opts.only_merge_on_switching_branches = 1;
-	}
-
-	options = parse_options_dup(checkout_options);
-	options = add_common_options(&opts, options);
-	options = add_common_switch_branch_options(&opts, options);
-	options = add_checkout_path_options(&opts, options);
-
-	ret = checkout_main(argc, argv, prefix, &opts,
-			    options, checkout_usage);
-	FREE_AND_NULL(options);
-	return ret;
-}
-
-int cmd_switch(int argc, const char **argv, const char *prefix)
-{
-	struct checkout_opts opts;
-	struct option *options = NULL;
-	struct option switch_options[] = {
-		OPT_STRING('c', "create", &opts.new_branch, N_("branch"),
-			   N_("create and switch to a new branch")),
-		OPT_STRING('C', "force-create", &opts.new_branch_force, N_("branch"),
-			   N_("create/reset and switch to a branch")),
-		OPT_BOOL(0, "guess", &opts.dwim_new_local_branch,
-			 N_("second guess 'git switch <no-such-branch>'")),
-		OPT_BOOL(0, "discard-changes", &opts.discard_changes,
-			 N_("throw away local modifications")),
-		OPT_END()
-	};
-	int ret;
-
-	memset(&opts, 0, sizeof(opts));
-	opts.dwim_new_local_branch = 1;
-	opts.accept_ref = 1;
-	opts.accept_pathspec = 0;
-	opts.switch_branch_doing_nothing_is_ok = 0;
-	opts.only_merge_on_switching_branches = 1;
-	opts.implicit_detach = 0;
-	opts.can_switch_when_in_progress = 0;
-	opts.orphan_from_empty_tree = 1;
-	opts.overlay_mode = -1;
-
-	options = parse_options_dup(switch_options);
-	options = add_common_options(&opts, options);
-	options = add_common_switch_branch_options(&opts, options);
-
-	cb_option = 'c';
-
-	ret = checkout_main(argc, argv, prefix, &opts,
-			    options, switch_branch_usage);
-	FREE_AND_NULL(options);
-	return ret;
-}
-
-int cmd_restore(int argc, const char **argv, const char *prefix)
-{
-	struct checkout_opts opts;
-	struct option *options;
-	struct option restore_options[] = {
-		OPT_STRING('s', "source", &opts.from_treeish, "<tree-ish>",
-			   N_("which tree-ish to checkout from")),
-		OPT_BOOL('S', "staged", &opts.checkout_index,
-			   N_("restore the index")),
-		OPT_BOOL('W', "worktree", &opts.checkout_worktree,
-			   N_("restore the working tree (default)")),
-		OPT_BOOL(0, "ignore-unmerged", &opts.ignore_unmerged,
-			 N_("ignore unmerged entries")),
-		OPT_BOOL(0, "overlay", &opts.overlay_mode, N_("use overlay mode")),
-		OPT_END()
-	};
-	int ret;
-
-	memset(&opts, 0, sizeof(opts));
-	opts.accept_ref = 0;
-	opts.accept_pathspec = 1;
-	opts.empty_pathspec_ok = 0;
-	opts.overlay_mode = 0;
-	opts.checkout_index = -1;    /* default off */
-	opts.checkout_worktree = -2; /* default on */
-	opts.ignore_unmerged_opt = "--ignore-unmerged";
-
-	options = parse_options_dup(restore_options);
-	options = add_common_options(&opts, options);
-	options = add_checkout_path_options(&opts, options);
-
-	ret = checkout_main(argc, argv, prefix, &opts,
-			    options, restore_usage);
-	FREE_AND_NULL(options);
-	return ret;
-}