From: Junio C Hamano <gitster@pobox.com>
Date: Wed, 6 Jul 2011 22:38:28 +0000 (-0700)
Subject: Merge commit 'v1.7.6' into jc/checkout-reflog-fix
X-Git-Tag: v1.7.6.1~19^2
X-Git-Url: https://git.tokkee.org/?a=commitdiff_plain;h=25d33546d474c7c28b72013c262fc23337cb3b21;p=git.git

Merge commit 'v1.7.6' into jc/checkout-reflog-fix

* commit 'v1.7.6': (3211 commits)
  Git 1.7.6
  completion: replace core.abbrevguard to core.abbrev
  Git 1.7.6-rc3
  Documentation: git diff --check respects core.whitespace
  gitweb: 'pickaxe' and 'grep' features requires 'search' to be enabled
  t7810: avoid unportable use of "echo"
  plug a few coverity-spotted leaks
  builtin/gc.c: add missing newline in message
  tests: link shell libraries into valgrind directory
  t/Makefile: pass test opts to valgrind target properly
  sh-i18n--envsubst.c: do not #include getopt.h
  Fix typo: existant->existent
  Git 1.7.6-rc2
  gitweb: do not misparse nonnumeric content tag files that contain a digit
  Git 1.7.6-rc1
  fetch: do not leak a refspec
  t3703: skip more tests using colons in file names on Windows
  gitweb: Fix usability of $prevent_xss
  gitweb: Move "Requirements" up in gitweb/INSTALL
  gitweb: Describe CSSMIN and JSMIN in gitweb/INSTALL
  ...
---

25d33546d474c7c28b72013c262fc23337cb3b21
diff --cc builtin/checkout.c
index 000000000,28cdc51b8..48de146b7
mode 000000,100644..100644
--- a/builtin/checkout.c
+++ b/builtin/checkout.c
@@@ -1,0 -1,1090 +1,1093 @@@
+ #include "cache.h"
+ #include "builtin.h"
+ #include "parse-options.h"
+ #include "refs.h"
+ #include "commit.h"
+ #include "tree.h"
+ #include "tree-walk.h"
+ #include "cache-tree.h"
+ #include "unpack-trees.h"
+ #include "dir.h"
+ #include "run-command.h"
+ #include "merge-recursive.h"
+ #include "branch.h"
+ #include "diff.h"
+ #include "revision.h"
+ #include "remote.h"
+ #include "blob.h"
+ #include "xdiff-interface.h"
+ #include "ll-merge.h"
+ #include "resolve-undo.h"
+ #include "submodule.h"
+ 
+ static const char * const checkout_usage[] = {
+ 	"git checkout [options] <branch>",
+ 	"git checkout [options] [<branch>] -- <file>...",
+ 	NULL,
+ };
+ 
+ struct checkout_opts {
+ 	int quiet;
+ 	int merge;
+ 	int force;
+ 	int force_detach;
+ 	int writeout_stage;
+ 	int writeout_error;
+ 
+ 	/* not set by parse_options */
+ 	int branch_exists;
+ 
+ 	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;
+ };
+ 
+ static int post_checkout_hook(struct commit *old, struct commit *new,
+ 			      int changed)
+ {
+ 	return run_hook(NULL, "post-checkout",
+ 			sha1_to_hex(old ? old->object.sha1 : null_sha1),
+ 			sha1_to_hex(new ? new->object.sha1 : null_sha1),
+ 			changed ? "1" : "0", NULL);
+ 	/* "new" can be NULL when checking out from the index before
+ 	   a commit exists. */
+ 
+ }
+ 
+ static int update_some(const unsigned char *sha1, const char *base, int baselen,
+ 		const char *pathname, unsigned mode, int stage, void *context)
+ {
+ 	int len;
+ 	struct cache_entry *ce;
+ 
+ 	if (S_ISDIR(mode))
+ 		return READ_TREE_RECURSIVE;
+ 
+ 	len = baselen + strlen(pathname);
+ 	ce = xcalloc(1, cache_entry_size(len));
+ 	hashcpy(ce->sha1, sha1);
+ 	memcpy(ce->name, base, baselen);
+ 	memcpy(ce->name + baselen, pathname, len - baselen);
+ 	ce->ce_flags = create_ce_flags(len, 0);
+ 	ce->ce_mode = create_ce_mode(mode);
+ 	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 char **pathspec)
+ {
+ 	struct pathspec ps;
+ 	init_pathspec(&ps, pathspec);
+ 	read_tree_recursive(tree, "", 0, 0, &ps, update_some, NULL);
+ 	free_pathspec(&ps);
+ 
+ 	/* 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(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, struct cache_entry *ce, int pos)
+ {
+ 	while (pos < active_nr &&
+ 	       !strcmp(active_cache[pos]->name, ce->name)) {
+ 		if (ce_stage(active_cache[pos]) == stage)
+ 			return 0;
+ 		pos++;
+ 	}
+ 	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_all_stages(struct cache_entry *ce, int pos)
+ {
+ 	if (ce_stage(ce) != 1 ||
+ 	    active_nr <= pos + 2 ||
+ 	    strcmp(active_cache[pos+1]->name, ce->name) ||
+ 	    ce_stage(active_cache[pos+1]) != 2 ||
+ 	    strcmp(active_cache[pos+2]->name, ce->name) ||
+ 	    ce_stage(active_cache[pos+2]) != 3)
+ 		return error(_("path '%s' does not have all three versions"),
+ 			     ce->name);
+ 	return 0;
+ }
+ 
+ static int checkout_stage(int stage, struct cache_entry *ce, int pos,
+ 			  struct checkout *state)
+ {
+ 	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);
+ 		pos++;
+ 	}
+ 	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, struct checkout *state)
+ {
+ 	struct cache_entry *ce = active_cache[pos];
+ 	const char *path = ce->name;
+ 	mmfile_t ancestor, ours, theirs;
+ 	int status;
+ 	unsigned char sha1[20];
+ 	mmbuffer_t result_buf;
+ 
+ 	if (ce_stage(ce) != 1 ||
+ 	    active_nr <= pos + 2 ||
+ 	    strcmp(active_cache[pos+1]->name, path) ||
+ 	    ce_stage(active_cache[pos+1]) != 2 ||
+ 	    strcmp(active_cache[pos+2]->name, path) ||
+ 	    ce_stage(active_cache[pos+2]) != 3)
+ 		return error(_("path '%s' does not have all 3 versions"), path);
+ 
+ 	read_mmblob(&ancestor, active_cache[pos]->sha1);
+ 	read_mmblob(&ours, active_cache[pos+1]->sha1);
+ 	read_mmblob(&theirs, active_cache[pos+2]->sha1);
+ 
+ 	/*
+ 	 * NEEDSWORK: re-create conflicts from merges with
+ 	 * merge.renormalize set, too
+ 	 */
+ 	status = ll_merge(&result_buf, path, &ancestor, "base",
+ 			  &ours, "ours", &theirs, "theirs", NULL);
+ 	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 just to leak.  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_sha1_file(result_buf.ptr, result_buf.size,
+ 			    blob_type, sha1))
+ 		die(_("Unable to add merge result for '%s'"), path);
+ 	ce = make_cache_entry(create_ce_mode(active_cache[pos+1]->ce_mode),
+ 			      sha1,
+ 			      path, 2, 0);
+ 	if (!ce)
+ 		die(_("make_cache_entry failed for path '%s'"), path);
+ 	status = checkout_entry(ce, state, NULL);
+ 	return status;
+ }
+ 
+ static int checkout_paths(struct tree *source_tree, const char **pathspec,
+ 			  struct checkout_opts *opts)
+ {
+ 	int pos;
+ 	struct checkout state;
+ 	static char *ps_matched;
+ 	unsigned char rev[20];
+ 	int flag;
+ 	struct commit *head;
+ 	int errs = 0;
+ 	int stage = opts->writeout_stage;
+ 	int merge = opts->merge;
+ 	int newfd;
+ 	struct lock_file *lock_file = xcalloc(1, sizeof(struct lock_file));
+ 
+ 	newfd = hold_locked_index(lock_file, 1);
+ 	if (read_cache_preload(pathspec) < 0)
+ 		return error(_("corrupt index file"));
+ 
+ 	if (source_tree)
+ 		read_tree_some(source_tree, pathspec);
+ 
+ 	for (pos = 0; pathspec[pos]; pos++)
+ 		;
+ 	ps_matched = xcalloc(1, pos);
+ 
+ 	for (pos = 0; pos < active_nr; pos++) {
+ 		struct cache_entry *ce = active_cache[pos];
+ 		match_pathspec(pathspec, ce->name, ce_namelen(ce), 0, ps_matched);
+ 	}
+ 
+ 	if (report_path_error(ps_matched, pathspec, 0))
+ 		return 1;
+ 
+ 	/* "checkout -m path" to recreate conflicted state */
+ 	if (opts->merge)
+ 		unmerge_cache(pathspec);
+ 
+ 	/* Any unmerged paths? */
+ 	for (pos = 0; pos < active_nr; pos++) {
+ 		struct cache_entry *ce = active_cache[pos];
+ 		if (match_pathspec(pathspec, ce->name, ce_namelen(ce), 0, NULL)) {
+ 			if (!ce_stage(ce))
+ 				continue;
+ 			if (opts->force) {
+ 				warning(_("path '%s' is unmerged"), ce->name);
+ 			} else if (stage) {
+ 				errs |= check_stage(stage, ce, pos);
+ 			} else if (opts->merge) {
+ 				errs |= check_all_stages(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 */
+ 	memset(&state, 0, sizeof(state));
+ 	state.force = 1;
+ 	state.refresh_cache = 1;
+ 	for (pos = 0; pos < active_nr; pos++) {
+ 		struct cache_entry *ce = active_cache[pos];
+ 		if (match_pathspec(pathspec, ce->name, ce_namelen(ce), 0, NULL)) {
+ 			if (!ce_stage(ce)) {
+ 				errs |= checkout_entry(ce, &state, NULL);
+ 				continue;
+ 			}
+ 			if (stage)
+ 				errs |= checkout_stage(stage, ce, pos, &state);
+ 			else if (merge)
+ 				errs |= checkout_merged(pos, &state);
+ 			pos = skip_same_name(ce, pos) - 1;
+ 		}
+ 	}
+ 
+ 	if (write_cache(newfd, active_cache, active_nr) ||
+ 	    commit_locked_index(lock_file))
+ 		die(_("unable to write new index file"));
+ 
+ 	resolve_ref("HEAD", rev, 0, &flag);
+ 	head = lookup_commit_reference_gently(rev, 1);
+ 
+ 	errs |= post_checkout_hook(head, head, 0);
+ 	return errs;
+ }
+ 
+ static void show_local_changes(struct object *head, struct diff_options *opts)
+ {
+ 	struct rev_info rev;
+ 	/* I think we want full paths, even if we're in a subdirectory. */
+ 	init_revisions(&rev, NULL);
+ 	rev.diffopt.flags = opts->flags;
+ 	rev.diffopt.output_format |= DIFF_FORMAT_NAME_STATUS;
+ 	if (diff_setup_done(&rev.diffopt) < 0)
+ 		die(_("diff_setup_done failed"));
+ 	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;
+ 	parse_commit(commit);
+ 	pp_commit_easy(CMIT_FMT_ONELINE, commit, &sb);
+ 	fprintf(stderr, "%s %s... %s\n", msg,
+ 		find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV), sb.buf);
+ 	strbuf_release(&sb);
+ }
+ 
+ static int reset_tree(struct tree *tree, struct checkout_opts *o, int worktree)
+ {
+ 	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->quiet;
+ 	opts.src_index = &the_index;
+ 	opts.dst_index = &the_index;
+ 	parse_tree(tree);
+ 	init_tree_desc(&tree_desc, tree->buffer, tree->size);
+ 	switch (unpack_trees(1, &tree_desc, &opts)) {
+ 	case -2:
+ 		o->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.
+ 		 */
+ 	case 0:
+ 		return 0;
+ 	default:
+ 		return 128;
+ 	}
+ }
+ 
+ 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 */
+ };
+ 
+ static void setup_branch_path(struct branch_info *branch)
+ {
+ 	struct strbuf buf = STRBUF_INIT;
+ 
+ 	strbuf_branchname(&buf, branch->name);
+ 	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(struct checkout_opts *opts,
+ 			      struct branch_info *old, struct branch_info *new)
+ {
+ 	int ret;
+ 	struct lock_file *lock_file = xcalloc(1, sizeof(struct lock_file));
+ 	int newfd = hold_locked_index(lock_file, 1);
+ 
+ 	if (read_cache_preload(NULL) < 0)
+ 		return error(_("corrupt index file"));
+ 
+ 	resolve_undo_clear();
+ 	if (opts->force) {
+ 		ret = reset_tree(new->commit->tree, opts, 1);
+ 		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.gently = opts->merge && old->commit;
+ 		topts.verbose_update = !opts->quiet;
+ 		topts.fn = twoway_merge;
+ 		topts.dir = xcalloc(1, sizeof(*topts.dir));
+ 		topts.dir->flags |= DIR_SHOW_IGNORED;
+ 		topts.dir->exclude_per_dir = ".gitignore";
+ 		tree = parse_tree_indirect(old->commit ?
+ 					   old->commit->object.sha1 :
+ 					   EMPTY_TREE_SHA1_BIN);
+ 		init_tree_desc(&trees[0], tree->buffer, tree->size);
+ 		tree = parse_tree_indirect(new->commit->object.sha1);
+ 		init_tree_desc(&trees[1], tree->buffer, tree->size);
+ 
+ 		ret = unpack_trees(2, trees, &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 *result;
+ 			struct tree *work;
+ 			struct merge_options o;
+ 			if (!opts->merge)
+ 				return 1;
+ 
+ 			/*
+ 			 * Without old->commit, the below is the same as
+ 			 * the two-tree unpack we already tried and failed.
+ 			 */
+ 			if (!old->commit)
+ 				return 1;
+ 
+ 			/* 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);
+ 			/*
+ 			 * NEEDSWORK: carrying over local changes
+ 			 * when branches have different end-of-line
+ 			 * normalization (or clean+smudge rules) is
+ 			 * a pain; plumb in an option to set
+ 			 * o.renormalize?
+ 			 */
+ 			init_merge_options(&o);
+ 			o.verbosity = 0;
+ 			work = write_tree_from_memory(&o);
+ 
+ 			ret = reset_tree(new->commit->tree, opts, 1);
+ 			if (ret)
+ 				return ret;
+ 			o.ancestor = old->name;
+ 			o.branch1 = new->name;
+ 			o.branch2 = "local";
+ 			merge_trees(&o, new->commit->tree, work,
+ 				old->commit->tree, &result);
+ 			ret = reset_tree(new->commit->tree, opts, 0);
+ 			if (ret)
+ 				return ret;
+ 		}
+ 	}
+ 
+ 	if (write_cache(newfd, active_cache, active_nr) ||
+ 	    commit_locked_index(lock_file))
+ 		die(_("unable to write new index file"));
+ 
+ 	if (!opts->force && !opts->quiet)
+ 		show_local_changes(&new->commit->object, &opts->diff_options);
+ 
+ 	return 0;
+ }
+ 
+ static void report_tracking(struct branch_info *new)
+ {
+ 	struct strbuf sb = STRBUF_INIT;
+ 	struct branch *branch = branch_get(new->name);
+ 
+ 	if (!format_tracking_info(branch, &sb))
+ 		return;
+ 	fputs(sb.buf, stdout);
+ 	strbuf_release(&sb);
+ }
+ 
+ static void detach_advice(const char *old_path, const char *new_name)
+ {
+ 	const char fmt[] =
+ 	"Note: checking out '%s'.\n\n"
+ 	"You are in 'detached HEAD' state. You can look around, make experimental\n"
+ 	"changes and commit them, and you can discard any commits you make in this\n"
+ 	"state without impacting any branches by performing another checkout.\n\n"
+ 	"If you want to create a new branch to retain commits you create, you may\n"
+ 	"do so (now or later) by using -b with the checkout command again. Example:\n\n"
+ 	"  git checkout -b new_branch_name\n\n";
+ 
+ 	fprintf(stderr, fmt, new_name);
+ }
+ 
+ static void update_refs_for_switch(struct checkout_opts *opts,
+ 				   struct branch_info *old,
+ 				   struct branch_info *new)
+ {
+ 	struct strbuf msg = STRBUF_INIT;
+ 	const char *old_desc;
+ 	if (opts->new_branch) {
+ 		if (opts->new_orphan_branch) {
+ 			if (opts->new_branch_log && !log_all_ref_updates) {
+ 				int temp;
+ 				char log_file[PATH_MAX];
+ 				char *ref_name = mkpath("refs/heads/%s", opts->new_orphan_branch);
+ 
+ 				temp = log_all_ref_updates;
+ 				log_all_ref_updates = 1;
+ 				if (log_ref_setup(ref_name, log_file, sizeof(log_file))) {
+ 					fprintf(stderr, _("Can not do reflog for '%s'\n"),
+ 					    opts->new_orphan_branch);
+ 					log_all_ref_updates = temp;
+ 					return;
+ 				}
+ 				log_all_ref_updates = temp;
+ 			}
+ 		}
+ 		else
+ 			create_branch(old->name, opts->new_branch, new->name,
+ 				      opts->new_branch_force ? 1 : 0,
+ 				      opts->new_branch_log, opts->track);
+ 		new->name = opts->new_branch;
+ 		setup_branch_path(new);
+ 	}
+ 
+ 	old_desc = old->name;
+ 	if (!old_desc && old->commit)
+ 		old_desc = sha1_to_hex(old->commit->object.sha1);
+ 	strbuf_addf(&msg, "checkout: moving from %s to %s",
+ 		    old_desc ? old_desc : "(invalid)", new->name);
+ 
+ 	if (!strcmp(new->name, "HEAD") && !new->path && !opts->force_detach) {
+ 		/* Nothing to do. */
+ 	} else if (opts->force_detach || !new->path) {	/* No longer on any branch. */
+ 		update_ref(msg.buf, "HEAD", new->commit->object.sha1, NULL,
+ 			   REF_NODEREF, DIE_ON_ERR);
+ 		if (!opts->quiet) {
+ 			if (old->path && advice_detached_head)
+ 				detach_advice(old->path, new->name);
+ 			describe_detached_head(_("HEAD is now at"), new->commit);
+ 		}
+ 	} else if (new->path) {	/* Switch branches. */
+ 		create_symref("HEAD", new->path, msg.buf);
+ 		if (!opts->quiet) {
+ 			if (old->path && !strcmp(new->path, old->path)) {
+ 				fprintf(stderr, _("Already on '%s'\n"),
+ 					new->name);
+ 			} else if (opts->new_branch) {
+ 				if (opts->branch_exists)
+ 					fprintf(stderr, _("Switched to and reset branch '%s'\n"), new->name);
+ 				else
+ 					fprintf(stderr, _("Switched to a new branch '%s'\n"), new->name);
+ 			} else {
+ 				fprintf(stderr, _("Switched to branch '%s'\n"),
+ 					new->name);
+ 			}
+ 		}
+ 		if (old->path && old->name) {
+ 			char log_file[PATH_MAX], ref_file[PATH_MAX];
+ 
+ 			git_snpath(log_file, sizeof(log_file), "logs/%s", old->path);
+ 			git_snpath(ref_file, sizeof(ref_file), "%s", old->path);
+ 			if (!file_exists(ref_file) && file_exists(log_file))
+ 				remove_path(log_file);
+ 		}
+ 	}
+ 	remove_branch_state();
+ 	strbuf_release(&msg);
+ 	if (!opts->quiet &&
+ 	    (new->path || (!opts->force_detach && !strcmp(new->name, "HEAD"))))
+ 		report_tracking(new);
+ }
+ 
+ struct rev_list_args {
+ 	int argc;
+ 	int alloc;
+ 	const char **argv;
+ };
+ 
+ static void add_one_rev_list_arg(struct rev_list_args *args, const char *s)
+ {
+ 	ALLOC_GROW(args->argv, args->argc + 1, args->alloc);
+ 	args->argv[args->argc++] = s;
+ }
+ 
+ static int add_one_ref_to_rev_list_arg(const char *refname,
+ 				       const unsigned char *sha1,
+ 				       int flags,
+ 				       void *cb_data)
+ {
+ 	add_one_rev_list_arg(cb_data, refname);
+ 	return 0;
+ }
+ 
+ static int clear_commit_marks_from_one_ref(const char *refname,
+ 				      const unsigned char *sha1,
+ 				      int flags,
+ 				      void *cb_data)
+ {
+ 	struct commit *commit = lookup_commit_reference_gently(sha1, 1);
+ 	if (commit)
+ 		clear_commit_marks(commit, -1);
+ 	return 0;
+ }
+ 
+ static void describe_one_orphan(struct strbuf *sb, struct commit *commit)
+ {
+ 	parse_commit(commit);
+ 	strbuf_addstr(sb, "  ");
+ 	strbuf_addstr(sb,
+ 		find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV));
+ 	strbuf_addch(sb, ' ');
+ 	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"
+ 		"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 */
+ 		"Warning: you are leaving %d commits behind, "
+ 		"not connected to\n"
+ 		"any of your branches:\n\n"
+ 		"%s\n"
+ 		"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),
+ 		lost,
+ 		sb.buf,
+ 		sha1_to_hex(commit->object.sha1));
+ 	strbuf_release(&sb);
+ }
+ 
+ /*
+  * 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 *commit)
+ {
+ 	struct rev_list_args args = { 0, 0, NULL };
+ 	struct rev_info revs;
+ 
+ 	add_one_rev_list_arg(&args, "(internal)");
+ 	add_one_rev_list_arg(&args, sha1_to_hex(commit->object.sha1));
+ 	add_one_rev_list_arg(&args, "--not");
+ 	for_each_ref(add_one_ref_to_rev_list_arg, &args);
+ 	add_one_rev_list_arg(&args, "--");
+ 	add_one_rev_list_arg(&args, NULL);
+ 
+ 	init_revisions(&revs, NULL);
+ 	if (setup_revisions(args.argc - 1, args.argv, &revs, NULL) != 1)
+ 		die(_("internal error: only -- alone should have been left"));
+ 	if (prepare_revision_walk(&revs))
+ 		die(_("internal error in revision walk"));
+ 	if (!(commit->object.flags & UNINTERESTING))
+ 		suggest_reattach(commit, &revs);
+ 	else
+ 		describe_detached_head(_("Previous HEAD position was"), commit);
+ 
+ 	clear_commit_marks(commit, -1);
+ 	for_each_ref(clear_commit_marks_from_one_ref, NULL);
+ }
+ 
+ static int switch_branches(struct checkout_opts *opts, struct branch_info *new)
+ {
+ 	int ret = 0;
+ 	struct branch_info old;
+ 	unsigned char rev[20];
+ 	int flag;
+ 	memset(&old, 0, sizeof(old));
 -	old.path = resolve_ref("HEAD", rev, 0, &flag);
++	old.path = xstrdup(resolve_ref("HEAD", rev, 0, &flag));
+ 	old.commit = lookup_commit_reference_gently(rev, 1);
 -	if (!(flag & REF_ISSYMREF))
++	if (!(flag & REF_ISSYMREF)) {
++		free((char *)old.path);
+ 		old.path = NULL;
++	}
+ 
+ 	if (old.path && !prefixcmp(old.path, "refs/heads/"))
+ 		old.name = old.path + strlen("refs/heads/");
+ 
+ 	if (!new->name) {
+ 		new->name = "HEAD";
+ 		new->commit = old.commit;
+ 		if (!new->commit)
+ 			die(_("You are on a branch yet to be born"));
+ 		parse_commit(new->commit);
+ 	}
+ 
+ 	ret = merge_working_tree(opts, &old, new);
+ 	if (ret)
+ 		return ret;
+ 
+ 	if (!opts->quiet && !old.path && old.commit && new->commit != old.commit)
+ 		orphaned_commit_warning(old.commit);
+ 
+ 	update_refs_for_switch(opts, &old, new);
+ 
+ 	ret = post_checkout_hook(old.commit, new->commit, 1);
++	free((char *)old.path);
+ 	return ret || opts->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 (!prefixcmp(var, "submodule."))
+ 		return parse_submodule_config_option(var, value);
+ 
+ 	return git_xmerge_config(var, value, NULL);
+ }
+ 
+ static int interactive_checkout(const char *revision, const char **pathspec,
+ 				struct checkout_opts *opts)
+ {
+ 	return run_add_interactive(revision, "--patch=checkout", pathspec);
+ }
+ 
+ struct tracking_name_data {
+ 	const char *name;
+ 	char *remote;
+ 	int unique;
+ };
+ 
+ static int check_tracking_name(const char *refname, const unsigned char *sha1,
+ 			       int flags, void *cb_data)
+ {
+ 	struct tracking_name_data *cb = cb_data;
+ 	const char *slash;
+ 
+ 	if (prefixcmp(refname, "refs/remotes/"))
+ 		return 0;
+ 	slash = strchr(refname + 13, '/');
+ 	if (!slash || strcmp(slash + 1, cb->name))
+ 		return 0;
+ 	if (cb->remote) {
+ 		cb->unique = 0;
+ 		return 0;
+ 	}
+ 	cb->remote = xstrdup(refname);
+ 	return 0;
+ }
+ 
+ static const char *unique_tracking_name(const char *name)
+ {
+ 	struct tracking_name_data cb_data = { NULL, NULL, 1 };
+ 	cb_data.name = name;
+ 	for_each_ref(check_tracking_name, &cb_data);
+ 	if (cb_data.unique)
+ 		return cb_data.remote;
+ 	free(cb_data.remote);
+ 	return NULL;
+ }
+ 
+ static int parse_branchname_arg(int argc, const char **argv,
+ 				int dwim_new_local_branch_ok,
+ 				struct branch_info *new,
+ 				struct tree **source_tree,
+ 				unsigned char rev[20],
+ 				const char **new_branch)
+ {
+ 	int argcount = 0;
+ 	unsigned char branch_rev[20];
+ 	const char *arg;
+ 	int has_dash_dash;
+ 
+ 	/*
+ 	 * 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> [<paths>]
+ 	 *
+ 	 *   With no paths, 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.
+ 	 *
+ 	 *   With no paths, if <something> is _not_ a commit, no -t nor -b
+ 	 *   was given, and there is a tracking branch whose name is
+ 	 *   <something> in one and only one remote, then this is a short-hand
+ 	 *   to fork local <something> from that remote-tracking branch.
+ 	 *
+ 	 *   Otherwise <something> shall 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 (!strcmp(argv[0], "--"))	/* case (2) */
+ 		return 1;
+ 
+ 	arg = argv[0];
+ 	has_dash_dash = (argc > 1) && !strcmp(argv[1], "--");
+ 
+ 	if (!strcmp(arg, "-"))
+ 		arg = "@{-1}";
+ 
+ 	if (get_sha1_mb(arg, rev)) {
+ 		if (has_dash_dash)          /* case (1) */
+ 			die(_("invalid reference: %s"), arg);
+ 		if (dwim_new_local_branch_ok &&
+ 		    !check_filename(NULL, arg) &&
+ 		    argc == 1) {
+ 			const char *remote = unique_tracking_name(arg);
+ 			if (!remote || get_sha1(remote, rev))
+ 				return argcount;
+ 			*new_branch = arg;
+ 			arg = remote;
+ 			/* DWIMmed to create local branch */
+ 		} else {
+ 			return argcount;
+ 		}
+ 	}
+ 
+ 	/* we can't end up being in (2) anymore, eat the argument */
+ 	argcount++;
+ 	argv++;
+ 	argc--;
+ 
+ 	new->name = arg;
+ 	setup_branch_path(new);
+ 
+ 	if (check_ref_format(new->path) == CHECK_REF_FORMAT_OK &&
+ 	    resolve_ref(new->path, branch_rev, 1, NULL))
+ 		hashcpy(rev, branch_rev);
+ 	else
+ 		new->path = NULL; /* not an existing branch */
+ 
+ 	new->commit = lookup_commit_reference_gently(rev, 1);
+ 	if (!new->commit) {
+ 		/* not a commit */
+ 		*source_tree = parse_tree_indirect(rev);
+ 	} else {
+ 		parse_commit(new->commit);
+ 		*source_tree = new->commit->tree;
+ 	}
+ 
+ 	if (!*source_tree)                   /* case (1): want a tree */
+ 		die(_("reference is not a tree: %s"), arg);
+ 	if (!has_dash_dash) {/* case (3 -> 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(NULL, arg);
+ 	} else {
+ 		argcount++;
+ 		argv++;
+ 		argc--;
+ 	}
+ 
+ 	return argcount;
+ }
+ 
+ int cmd_checkout(int argc, const char **argv, const char *prefix)
+ {
+ 	struct checkout_opts opts;
+ 	unsigned char rev[20];
+ 	struct branch_info new;
+ 	struct tree *source_tree = NULL;
+ 	char *conflict_style = NULL;
+ 	int patch_mode = 0;
+ 	int dwim_new_local_branch = 1;
+ 	struct option options[] = {
+ 		OPT__QUIET(&opts.quiet, "suppress progress reporting"),
+ 		OPT_STRING('b', NULL, &opts.new_branch, "branch",
+ 			   "create and checkout a new branch"),
+ 		OPT_STRING('B', NULL, &opts.new_branch_force, "branch",
+ 			   "create/reset and checkout a branch"),
+ 		OPT_BOOLEAN('l', NULL, &opts.new_branch_log, "create reflog for new branch"),
+ 		OPT_BOOLEAN(0, "detach", &opts.force_detach, "detach the HEAD at named commit"),
+ 		OPT_SET_INT('t', "track",  &opts.track, "set upstream info for new branch",
+ 			BRANCH_TRACK_EXPLICIT),
+ 		OPT_STRING(0, "orphan", &opts.new_orphan_branch, "new branch", "new unparented branch"),
+ 		OPT_SET_INT('2', "ours", &opts.writeout_stage, "checkout our version for unmerged files",
+ 			    2),
+ 		OPT_SET_INT('3', "theirs", &opts.writeout_stage, "checkout their version for unmerged files",
+ 			    3),
+ 		OPT__FORCE(&opts.force, "force checkout (throw away local modifications)"),
+ 		OPT_BOOLEAN('m', "merge", &opts.merge, "perform a 3-way merge with the new branch"),
+ 		OPT_STRING(0, "conflict", &conflict_style, "style",
+ 			   "conflict style (merge or diff3)"),
+ 		OPT_BOOLEAN('p', "patch", &patch_mode, "select hunks interactively"),
+ 		{ OPTION_BOOLEAN, 0, "guess", &dwim_new_local_branch, NULL,
+ 		  "second guess 'git checkout no-such-branch'",
+ 		  PARSE_OPT_NOARG | PARSE_OPT_HIDDEN },
+ 		OPT_END(),
+ 	};
+ 
+ 	memset(&opts, 0, sizeof(opts));
+ 	memset(&new, 0, sizeof(new));
+ 
+ 	gitmodules_config();
+ 	git_config(git_checkout_config, &opts);
+ 
+ 	opts.track = BRANCH_TRACK_UNSPECIFIED;
+ 
+ 	argc = parse_options(argc, argv, prefix, options, checkout_usage,
+ 			     PARSE_OPT_KEEP_DASHDASH);
+ 
+ 	/* we can assume from now on new_branch = !new_branch_force */
+ 	if (opts.new_branch && opts.new_branch_force)
+ 		die(_("-B cannot be used with -b"));
+ 
+ 	/* copy -B over to -b, so that we can just check the latter */
+ 	if (opts.new_branch_force)
+ 		opts.new_branch = opts.new_branch_force;
+ 
+ 	if (patch_mode && (opts.track > 0 || opts.new_branch
+ 			   || opts.new_branch_log || opts.merge || opts.force
+ 			   || opts.force_detach))
+ 		die (_("--patch is incompatible with all other options"));
+ 
+ 	if (opts.force_detach && (opts.new_branch || opts.new_orphan_branch))
+ 		die(_("--detach cannot be used with -b/-B/--orphan"));
+ 	if (opts.force_detach && 0 < opts.track)
+ 		die(_("--detach cannot be used with -t"));
+ 
+ 	/* --track without -b should DWIM */
+ 	if (0 < opts.track && !opts.new_branch) {
+ 		const char *argv0 = argv[0];
+ 		if (!argc || !strcmp(argv0, "--"))
+ 			die (_("--track needs a branch name"));
+ 		if (!prefixcmp(argv0, "refs/"))
+ 			argv0 += 5;
+ 		if (!prefixcmp(argv0, "remotes/"))
+ 			argv0 += 8;
+ 		argv0 = strchr(argv0, '/');
+ 		if (!argv0 || !argv0[1])
+ 			die (_("Missing branch name; try -b"));
+ 		opts.new_branch = argv0 + 1;
+ 	}
+ 
+ 	if (opts.new_orphan_branch) {
+ 		if (opts.new_branch)
+ 			die(_("--orphan and -b|-B are mutually exclusive"));
+ 		if (opts.track > 0)
+ 			die(_("--orphan cannot be used with -t"));
+ 		opts.new_branch = opts.new_orphan_branch;
+ 	}
+ 
+ 	if (conflict_style) {
+ 		opts.merge = 1; /* implied */
+ 		git_xmerge_config("merge.conflictstyle", conflict_style, NULL);
+ 	}
+ 
+ 	if (opts.force && opts.merge)
+ 		die(_("git checkout: -f and -m are incompatible"));
+ 
+ 	/*
+ 	 * 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) {
+ 		int dwim_ok =
+ 			!patch_mode &&
+ 			dwim_new_local_branch &&
+ 			opts.track == BRANCH_TRACK_UNSPECIFIED &&
+ 			!opts.new_branch;
+ 		int n = parse_branchname_arg(argc, argv, dwim_ok,
+ 				&new, &source_tree, rev, &opts.new_branch);
+ 		argv += n;
+ 		argc -= n;
+ 	}
+ 
+ 	if (opts.track == BRANCH_TRACK_UNSPECIFIED)
+ 		opts.track = git_branch_track;
+ 
+ 	if (argc) {
+ 		const char **pathspec = get_pathspec(prefix, argv);
+ 
+ 		if (!pathspec)
+ 			die(_("invalid path specification"));
+ 
+ 		if (patch_mode)
+ 			return interactive_checkout(new.name, pathspec, &opts);
+ 
+ 		/* Checkout paths */
+ 		if (opts.new_branch) {
+ 			if (argc == 1) {
+ 				die(_("git checkout: updating paths is incompatible with switching branches.\nDid you intend to checkout '%s' which can not be resolved as commit?"), argv[0]);
+ 			} else {
+ 				die(_("git checkout: updating paths is incompatible with switching branches."));
+ 			}
+ 		}
+ 
+ 		if (opts.force_detach)
+ 			die(_("git checkout: --detach does not take a path argument"));
+ 
+ 		if (1 < !!opts.writeout_stage + !!opts.force + !!opts.merge)
+ 			die(_("git checkout: --ours/--theirs, --force and --merge are incompatible when\nchecking out of the index."));
+ 
+ 		return checkout_paths(source_tree, pathspec, &opts);
+ 	}
+ 
+ 	if (patch_mode)
+ 		return interactive_checkout(new.name, NULL, &opts);
+ 
+ 	if (opts.new_branch) {
+ 		struct strbuf buf = STRBUF_INIT;
+ 		if (strbuf_check_branch_ref(&buf, opts.new_branch))
+ 			die(_("git checkout: we do not like '%s' as a branch name."),
+ 			    opts.new_branch);
+ 		if (!get_sha1(buf.buf, rev)) {
+ 			opts.branch_exists = 1;
+ 			if (!opts.new_branch_force)
+ 				die(_("git checkout: branch %s already exists"),
+ 				    opts.new_branch);
+ 		}
+ 		strbuf_release(&buf);
+ 	}
+ 
+ 	if (new.name && !new.commit) {
+ 		die(_("Cannot switch branch to a non-commit."));
+ 	}
+ 	if (opts.writeout_stage)
+ 		die(_("--ours/--theirs is incompatible with switching branches."));
+ 
+ 	return switch_branches(&opts, &new);
+ }