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-rw-r--r--builtin/checkout.c1499
1 files changed, 1499 insertions, 0 deletions
diff --git a/builtin/checkout.c b/builtin/checkout.c
new file mode 100644
index 0000000000..2f92328db4
--- /dev/null
+++ b/builtin/checkout.c
@@ -0,0 +1,1499 @@
+#include "builtin.h"
+#include "lockfile.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"
+#include "argv-array.h"
+#include "sigchain.h"
+
+static const char * const checkout_usage[] = {
+ N_("git checkout [<options>] <branch>"),
+ N_("git checkout [<options>] [<branch>] -- <file>..."),
+ NULL,
+};
+
+struct checkout_opts {
+ int patch_mode;
+ int quiet;
+ int merge;
+ int force;
+ int force_detach;
+ int writeout_stage;
+ int overwrite_ignore;
+ int ignore_skipworktree;
+ int ignore_other_worktrees;
+
+ 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;
+
+ int branch_exists;
+ const char *prefix;
+ struct pathspec pathspec;
+ struct tree *source_tree;
+
+ const char *new_worktree;
+ const char **saved_argv;
+ int new_worktree_mode;
+};
+
+static int post_checkout_hook(struct commit *old, struct commit *new,
+ int changed)
+{
+ return run_hook_le(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, 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 = xcalloc(1, cache_entry_size(len));
+ hashcpy(ce->sha1, sha1);
+ 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 &&
+ !hashcmp(ce->sha1, old->sha1)) {
+ old->ce_flags |= CE_UPDATE;
+ free(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(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)
+{
+ 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_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, 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;
+ unsigned char threeway[3][20];
+ unsigned mode = 0;
+
+ memset(threeway, 0, sizeof(threeway));
+ while (pos < active_nr) {
+ int stage;
+ stage = ce_stage(ce);
+ if (!stage || strcmp(path, ce->name))
+ break;
+ hashcpy(threeway[stage - 1], ce->sha1);
+ if (stage == 2)
+ mode = create_ce_mode(ce->ce_mode);
+ pos++;
+ ce = active_cache[pos];
+ }
+ if (is_null_sha1(threeway[1]) || is_null_sha1(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]);
+
+ /*
+ * 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(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(const struct checkout_opts *opts,
+ const char *revision)
+{
+ int pos;
+ struct checkout state;
+ static char *ps_matched;
+ unsigned char rev[20];
+ int flag;
+ struct commit *head;
+ int errs = 0;
+ struct lock_file *lock_file;
+
+ 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->force && opts->patch_mode)
+ die(_("'%s' cannot be used with updating paths"), "-f");
+
+ 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->force && opts->merge)
+ die(_("'%s' cannot be used with %s"), "-f", "-m");
+
+ if (opts->new_branch)
+ die(_("Cannot update paths and switch to branch '%s' at the same time."),
+ opts->new_branch);
+
+ if (opts->new_worktree)
+ die(_("'%s' cannot be used with updating paths"), "--to");
+
+ if (opts->patch_mode)
+ return run_add_interactive(revision, "--patch=checkout",
+ &opts->pathspec);
+
+ lock_file = xcalloc(1, sizeof(struct lock_file));
+
+ hold_locked_index(lock_file, 1);
+ if (read_cache_preload(&opts->pathspec) < 0)
+ return error(_("corrupt index file"));
+
+ if (opts->source_tree)
+ read_tree_some(opts->source_tree, &opts->pathspec);
+
+ ps_matched = xcalloc(1, opts->pathspec.nr);
+
+ /*
+ * Make sure all pathspecs participated in locating the paths
+ * to be checked out.
+ */
+ for (pos = 0; pos < active_nr; pos++) {
+ struct cache_entry *ce = active_cache[pos];
+ ce->ce_flags &= ~CE_MATCHED;
+ if (!opts->ignore_skipworktree && ce_skip_worktree(ce))
+ continue;
+ if (opts->source_tree && !(ce->ce_flags & CE_UPDATE))
+ /*
+ * "git checkout tree-ish -- path", but this entry
+ * is in the original index; it will not be checked
+ * out to the working tree and it does not matter
+ * if pathspec matched this entry. We will not do
+ * anything to this entry at all.
+ */
+ continue;
+ /*
+ * 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(ce, &opts->pathspec, ps_matched))
+ ce->ce_flags |= CE_MATCHED;
+ }
+
+ if (report_path_error(ps_matched, &opts->pathspec, opts->prefix)) {
+ 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->force) {
+ warning(_("path '%s' is unmerged"), ce->name);
+ } else if (opts->writeout_stage) {
+ errs |= check_stage(opts->writeout_stage, ce, pos);
+ } 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 */
+ memset(&state, 0, sizeof(state));
+ state.force = 1;
+ state.refresh_cache = 1;
+ state.istate = &the_index;
+ 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);
+ continue;
+ }
+ if (opts->writeout_stage)
+ errs |= checkout_stage(opts->writeout_stage, ce, pos, &state);
+ else if (opts->merge)
+ errs |= checkout_merged(pos, &state);
+ pos = skip_same_name(ce, pos) - 1;
+ }
+ }
+
+ if (write_locked_index(&the_index, lock_file, COMMIT_LOCK))
+ die(_("unable to write new index file"));
+
+ read_ref_full("HEAD", 0, rev, &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,
+ const 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;
+ 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);
+ 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, const struct checkout_opts *o,
+ int worktree, int *writeout_error)
+{
+ 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 && isatty(2);
+ 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:
+ *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 */
+ /*
+ * if not null the branch is detached because it's already
+ * checked out in this checkout
+ */
+ char *checkout;
+};
+
+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(const struct checkout_opts *opts,
+ struct branch_info *old,
+ struct branch_info *new,
+ int *writeout_error)
+{
+ int ret;
+ struct lock_file *lock_file = xcalloc(1, sizeof(struct lock_file));
+
+ 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, writeout_error);
+ 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 && isatty(2);
+ topts.fn = twoway_merge;
+ 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->commit && !opts->new_worktree_mode ?
+ 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,
+ writeout_error);
+ 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,
+ writeout_error);
+ 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->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 update_refs_for_switch(const struct checkout_opts *opts,
+ struct branch_info *old,
+ struct branch_info *new)
+{
+ struct strbuf msg = STRBUF_INIT;
+ const char *old_desc, *reflog_msg;
+ if (opts->new_branch) {
+ if (opts->new_orphan_branch) {
+ if (opts->new_branch_log && !log_all_ref_updates) {
+ int temp;
+ struct strbuf log_file = STRBUF_INIT;
+ int ret;
+ const char *ref_name;
+
+ ref_name = mkpath("refs/heads/%s", opts->new_orphan_branch);
+ temp = log_all_ref_updates;
+ log_all_ref_updates = 1;
+ ret = log_ref_setup(ref_name, &log_file);
+ log_all_ref_updates = temp;
+ strbuf_release(&log_file);
+ if (ret) {
+ fprintf(stderr, _("Can not do reflog for '%s'\n"),
+ opts->new_orphan_branch);
+ return;
+ }
+ }
+ }
+ else
+ create_branch(old->name, opts->new_branch, new->name,
+ opts->new_branch_force ? 1 : 0,
+ opts->new_branch_log,
+ opts->new_branch_force ? 1 : 0,
+ opts->quiet,
+ 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);
+
+ reflog_msg = getenv("GIT_REFLOG_ACTION");
+ if (!reflog_msg)
+ strbuf_addf(&msg, "checkout: moving from %s to %s",
+ old_desc ? old_desc : "(invalid)", new->name);
+ else
+ strbuf_insert(&msg, 0, reflog_msg, strlen(reflog_msg));
+
+ 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, UPDATE_REFS_DIE_ON_ERR);
+ if (!opts->quiet) {
+ if (old->path && advice_detached_head)
+ detach_advice(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)) {
+ if (opts->new_branch_force)
+ fprintf(stderr, _("Reset branch '%s'\n"),
+ new->name);
+ else
+ 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) {
+ if (!ref_exists(old->path) && reflog_exists(old->path))
+ delete_reflog(old->path);
+ }
+ }
+ remove_branch_state();
+ strbuf_release(&msg);
+ if (!opts->quiet &&
+ (new->path || (!opts->force_detach && !strcmp(new->name, "HEAD"))))
+ report_tracking(new);
+}
+
+static int add_pending_uninteresting_ref(const char *refname,
+ const unsigned char *sha1,
+ int flags, void *cb_data)
+{
+ add_pending_sha1(cb_data, refname, sha1, UNINTERESTING);
+ return 0;
+}
+
+static void describe_one_orphan(struct strbuf *sb, struct commit *commit)
+{
+ strbuf_addstr(sb, " ");
+ strbuf_addstr(sb,
+ find_unique_abbrev(commit->object.sha1, 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.sha1, 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, struct commit *new)
+{
+ struct rev_info revs;
+ struct object *object = &old->object;
+ struct object_array refs;
+
+ init_revisions(&revs, NULL);
+ setup_revisions(0, NULL, &revs, NULL);
+
+ object->flags &= ~UNINTERESTING;
+ add_pending_object(&revs, object, sha1_to_hex(object->sha1));
+
+ for_each_ref(add_pending_uninteresting_ref, &revs);
+ add_pending_sha1(&revs, "HEAD", new->object.sha1, UNINTERESTING);
+
+ refs = revs.pending;
+ revs.leak_pending = 1;
+
+ if (prepare_revision_walk(&revs))
+ die(_("internal error in revision walk"));
+ if (!(old->object.flags & UNINTERESTING))
+ suggest_reattach(old, &revs);
+ else
+ describe_detached_head(_("Previous HEAD position was"), old);
+
+ clear_commit_marks_for_object_array(&refs, ALL_REV_FLAGS);
+ free(refs.objects);
+}
+
+static int switch_branches(const struct checkout_opts *opts,
+ struct branch_info *new)
+{
+ int ret = 0;
+ struct branch_info old;
+ void *path_to_free;
+ unsigned char rev[20];
+ int flag, writeout_error = 0;
+ memset(&old, 0, sizeof(old));
+ old.path = path_to_free = resolve_refdup("HEAD", 0, rev, &flag);
+ old.commit = lookup_commit_reference_gently(rev, 1);
+ if (!(flag & REF_ISSYMREF))
+ old.path = NULL;
+
+ if (old.path)
+ skip_prefix(old.path, "refs/heads/", &old.name);
+
+ 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_or_die(new->commit);
+ }
+
+ ret = merge_working_tree(opts, &old, new, &writeout_error);
+ if (ret) {
+ free(path_to_free);
+ return ret;
+ }
+
+ if (!opts->quiet && !old.path && old.commit &&
+ new->commit != old.commit && !opts->new_worktree_mode)
+ orphaned_commit_warning(old.commit, new->commit);
+
+ update_refs_for_switch(opts, &old, new);
+
+ ret = post_checkout_hook(old.commit, new->commit, 1);
+ free(path_to_free);
+ return ret || writeout_error;
+}
+
+static char *junk_work_tree;
+static char *junk_git_dir;
+static int is_junk;
+static pid_t junk_pid;
+
+static void remove_junk(void)
+{
+ struct strbuf sb = STRBUF_INIT;
+ if (!is_junk || getpid() != junk_pid)
+ return;
+ if (junk_git_dir) {
+ strbuf_addstr(&sb, junk_git_dir);
+ remove_dir_recursively(&sb, 0);
+ strbuf_reset(&sb);
+ }
+ if (junk_work_tree) {
+ strbuf_addstr(&sb, junk_work_tree);
+ remove_dir_recursively(&sb, 0);
+ }
+ strbuf_release(&sb);
+}
+
+static void remove_junk_on_signal(int signo)
+{
+ remove_junk();
+ sigchain_pop(signo);
+ raise(signo);
+}
+
+static int prepare_linked_checkout(const struct checkout_opts *opts,
+ struct branch_info *new)
+{
+ struct strbuf sb_git = STRBUF_INIT, sb_repo = STRBUF_INIT;
+ struct strbuf sb = STRBUF_INIT;
+ const char *path = opts->new_worktree, *name;
+ struct stat st;
+ struct child_process cp;
+ int counter = 0, len, ret;
+
+ if (!new->commit)
+ die(_("no branch specified"));
+ if (file_exists(path) && !is_empty_dir(path))
+ die(_("'%s' already exists"), path);
+
+ len = strlen(path);
+ while (len && is_dir_sep(path[len - 1]))
+ len--;
+
+ for (name = path + len - 1; name > path; name--)
+ if (is_dir_sep(*name)) {
+ name++;
+ break;
+ }
+ strbuf_addstr(&sb_repo,
+ git_path("worktrees/%.*s", (int)(path + len - name), name));
+ len = sb_repo.len;
+ if (safe_create_leading_directories_const(sb_repo.buf))
+ die_errno(_("could not create leading directories of '%s'"),
+ sb_repo.buf);
+ while (!stat(sb_repo.buf, &st)) {
+ counter++;
+ strbuf_setlen(&sb_repo, len);
+ strbuf_addf(&sb_repo, "%d", counter);
+ }
+ name = strrchr(sb_repo.buf, '/') + 1;
+
+ junk_pid = getpid();
+ atexit(remove_junk);
+ sigchain_push_common(remove_junk_on_signal);
+
+ if (mkdir(sb_repo.buf, 0777))
+ die_errno(_("could not create directory of '%s'"), sb_repo.buf);
+ junk_git_dir = xstrdup(sb_repo.buf);
+ is_junk = 1;
+
+ /*
+ * lock the incomplete repo so prune won't delete it, unlock
+ * after the preparation is over.
+ */
+ strbuf_addf(&sb, "%s/locked", sb_repo.buf);
+ write_file(sb.buf, 1, "initializing\n");
+
+ strbuf_addf(&sb_git, "%s/.git", path);
+ if (safe_create_leading_directories_const(sb_git.buf))
+ die_errno(_("could not create leading directories of '%s'"),
+ sb_git.buf);
+ junk_work_tree = xstrdup(path);
+
+ strbuf_reset(&sb);
+ strbuf_addf(&sb, "%s/gitdir", sb_repo.buf);
+ write_file(sb.buf, 1, "%s\n", real_path(sb_git.buf));
+ write_file(sb_git.buf, 1, "gitdir: %s/worktrees/%s\n",
+ real_path(get_git_common_dir()), name);
+ /*
+ * This is to keep resolve_ref() happy. We need a valid HEAD
+ * or is_git_directory() will reject the directory. Any valid
+ * value would do because this value will be ignored and
+ * replaced at the next (real) checkout.
+ */
+ strbuf_reset(&sb);
+ strbuf_addf(&sb, "%s/HEAD", sb_repo.buf);
+ write_file(sb.buf, 1, "%s\n", sha1_to_hex(new->commit->object.sha1));
+ strbuf_reset(&sb);
+ strbuf_addf(&sb, "%s/commondir", sb_repo.buf);
+ write_file(sb.buf, 1, "../..\n");
+
+ if (!opts->quiet)
+ fprintf_ln(stderr, _("Enter %s (identifier %s)"), path, name);
+
+ setenv("GIT_CHECKOUT_NEW_WORKTREE", "1", 1);
+ setenv(GIT_DIR_ENVIRONMENT, sb_git.buf, 1);
+ setenv(GIT_WORK_TREE_ENVIRONMENT, path, 1);
+ memset(&cp, 0, sizeof(cp));
+ cp.git_cmd = 1;
+ cp.argv = opts->saved_argv;
+ ret = run_command(&cp);
+ if (!ret) {
+ is_junk = 0;
+ free(junk_work_tree);
+ free(junk_git_dir);
+ junk_work_tree = NULL;
+ junk_git_dir = NULL;
+ }
+ strbuf_reset(&sb);
+ strbuf_addf(&sb, "%s/locked", sb_repo.buf);
+ unlink_or_warn(sb.buf);
+ strbuf_release(&sb);
+ strbuf_release(&sb_repo);
+ strbuf_release(&sb_git);
+ return ret;
+}
+
+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 parse_submodule_config_option(var, value);
+
+ return git_xmerge_config(var, value, NULL);
+}
+
+struct tracking_name_data {
+ /* const */ char *src_ref;
+ char *dst_ref;
+ unsigned char *dst_sha1;
+ int unique;
+};
+
+static int check_tracking_name(struct remote *remote, void *cb_data)
+{
+ struct tracking_name_data *cb = cb_data;
+ struct refspec query;
+ memset(&query, 0, sizeof(struct refspec));
+ query.src = cb->src_ref;
+ if (remote_find_tracking(remote, &query) ||
+ get_sha1(query.dst, cb->dst_sha1)) {
+ free(query.dst);
+ return 0;
+ }
+ if (cb->dst_ref) {
+ free(query.dst);
+ cb->unique = 0;
+ return 0;
+ }
+ cb->dst_ref = query.dst;
+ return 0;
+}
+
+static const char *unique_tracking_name(const char *name, unsigned char *sha1)
+{
+ struct tracking_name_data cb_data = { NULL, NULL, NULL, 1 };
+ char src_ref[PATH_MAX];
+ snprintf(src_ref, PATH_MAX, "refs/heads/%s", name);
+ cb_data.src_ref = src_ref;
+ cb_data.dst_sha1 = sha1;
+ for_each_remote(check_tracking_name, &cb_data);
+ if (cb_data.unique)
+ return cb_data.dst_ref;
+ free(cb_data.dst_ref);
+ return NULL;
+}
+
+static void check_linked_checkout(struct branch_info *new, const char *id)
+{
+ struct strbuf sb = STRBUF_INIT;
+ struct strbuf path = STRBUF_INIT;
+ struct strbuf gitdir = STRBUF_INIT;
+ const char *start, *end;
+
+ if (id)
+ strbuf_addf(&path, "%s/worktrees/%s/HEAD", get_git_common_dir(), id);
+ else
+ strbuf_addf(&path, "%s/HEAD", get_git_common_dir());
+
+ if (strbuf_read_file(&sb, path.buf, 0) < 0 ||
+ !skip_prefix(sb.buf, "ref:", &start))
+ goto done;
+ while (isspace(*start))
+ start++;
+ end = start;
+ while (*end && !isspace(*end))
+ end++;
+ if (strncmp(start, new->path, end - start) || new->path[end - start] != '\0')
+ goto done;
+ if (id) {
+ strbuf_reset(&path);
+ strbuf_addf(&path, "%s/worktrees/%s/gitdir", get_git_common_dir(), id);
+ if (strbuf_read_file(&gitdir, path.buf, 0) <= 0)
+ goto done;
+ strbuf_rtrim(&gitdir);
+ } else
+ strbuf_addstr(&gitdir, get_git_common_dir());
+ die(_("'%s' is already checked out at '%s'"), new->name, gitdir.buf);
+done:
+ strbuf_release(&path);
+ strbuf_release(&sb);
+ strbuf_release(&gitdir);
+}
+
+static void check_linked_checkouts(struct branch_info *new)
+{
+ struct strbuf path = STRBUF_INIT;
+ DIR *dir;
+ struct dirent *d;
+
+ strbuf_addf(&path, "%s/worktrees", get_git_common_dir());
+ if ((dir = opendir(path.buf)) == NULL) {
+ strbuf_release(&path);
+ return;
+ }
+
+ /*
+ * $GIT_COMMON_DIR/HEAD is practically outside
+ * $GIT_DIR so resolve_ref_unsafe() won't work (it
+ * uses git_path). Parse the ref ourselves.
+ */
+ check_linked_checkout(new, NULL);
+
+ while ((d = readdir(dir)) != NULL) {
+ if (!strcmp(d->d_name, ".") || !strcmp(d->d_name, ".."))
+ continue;
+ check_linked_checkout(new, d->d_name);
+ }
+ strbuf_release(&path);
+ closedir(dir);
+}
+
+static int parse_branchname_arg(int argc, const char **argv,
+ int dwim_new_local_branch_ok,
+ struct branch_info *new,
+ struct checkout_opts *opts,
+ unsigned char rev[20])
+{
+ struct tree **source_tree = &opts->source_tree;
+ const char **new_branch = &opts->new_branch;
+ int force_detach = opts->force_detach;
+ int argcount = 0;
+ unsigned char branch_rev[20];
+ 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, 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;
+
+ arg = argv[0];
+ dash_dash_pos = -1;
+ for (i = 0; i < argc; i++) {
+ if (!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);
+
+ if (!strcmp(arg, "-"))
+ arg = "@{-1}";
+
+ if (get_sha1_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;
+
+ if (check_filename(NULL, arg) && !has_dash_dash)
+ recover_with_dwim = 0;
+ /*
+ * Accept "git checkout foo" and "git checkout foo --"
+ * as candidates for dwim.
+ */
+ if (!(argc == 1 && !has_dash_dash) &&
+ !(argc == 2 && has_dash_dash))
+ recover_with_dwim = 0;
+
+ if (recover_with_dwim) {
+ const char *remote = unique_tracking_name(arg, rev);
+ 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--;
+
+ new->name = arg;
+ setup_branch_path(new);
+
+ if (!check_refname_format(new->path, 0) &&
+ !read_ref(new->path, branch_rev))
+ hashcpy(rev, branch_rev);
+ else
+ new->path = NULL; /* not an existing branch */
+
+ if (new->path && !force_detach && !*new_branch) {
+ unsigned char sha1[20];
+ int flag;
+ char *head_ref = resolve_refdup("HEAD", 0, sha1, &flag);
+ if (head_ref &&
+ (!(flag & REF_ISSYMREF) || strcmp(head_ref, new->path)) &&
+ !opts->ignore_other_worktrees)
+ check_linked_checkouts(new);
+ free(head_ref);
+ }
+
+ new->commit = lookup_commit_reference_gently(rev, 1);
+ if (!new->commit) {
+ /* not a commit */
+ *source_tree = parse_tree_indirect(rev);
+ } else {
+ parse_commit_or_die(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).(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(NULL, arg);
+ } else {
+ 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;
+
+ 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 int checkout_branch(struct checkout_opts *opts,
+ struct branch_info *new)
+{
+ 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->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->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");
+ } 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->name && !new->commit)
+ die(_("Cannot switch branch to a non-commit '%s'"),
+ new->name);
+
+ if (opts->new_worktree)
+ return prepare_linked_checkout(opts, new);
+
+ if (!new->commit && opts->new_branch) {
+ unsigned char rev[20];
+ int flag;
+
+ if (!read_ref_full("HEAD", 0, rev, &flag) &&
+ (flag & REF_ISSYMREF) && is_null_sha1(rev))
+ return switch_unborn_to_new_branch(opts);
+ }
+ return switch_branches(opts, new);
+}
+
+int cmd_checkout(int argc, const char **argv, const char *prefix)
+{
+ struct checkout_opts opts;
+ struct branch_info new;
+ char *conflict_style = NULL;
+ int dwim_new_local_branch = 1;
+ struct option options[] = {
+ OPT__QUIET(&opts.quiet, N_("suppress progress reporting")),
+ 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, "detach", &opts.force_detach, N_("detach the HEAD at named commit")),
+ OPT_SET_INT('t', "track", &opts.track, N_("set upstream info for new branch"),
+ BRANCH_TRACK_EXPLICIT),
+ OPT_STRING(0, "orphan", &opts.new_orphan_branch, N_("new-branch"), N_("new unparented branch")),
+ OPT_SET_INT('2', "ours", &opts.writeout_stage, N_("checkout our version for unmerged files"),
+ 2),
+ OPT_SET_INT('3', "theirs", &opts.writeout_stage, N_("checkout their version for unmerged files"),
+ 3),
+ OPT__FORCE(&opts.force, N_("force checkout (throw away local modifications)")),
+ OPT_BOOL('m', "merge", &opts.merge, N_("perform a 3-way merge with the new branch")),
+ OPT_BOOL(0, "overwrite-ignore", &opts.overwrite_ignore, N_("update ignored files (default)")),
+ OPT_STRING(0, "conflict", &conflict_style, N_("style"),
+ N_("conflict style (merge or diff3)")),
+ 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_HIDDEN_BOOL(0, "guess", &dwim_new_local_branch,
+ N_("second guess 'git checkout <no-such-branch>'")),
+ OPT_FILENAME(0, "to", &opts.new_worktree,
+ N_("check a branch out in a separate working directory")),
+ OPT_BOOL(0, "ignore-other-worktrees", &opts.ignore_other_worktrees,
+ N_("do not check if another worktree is holding the given ref")),
+ OPT_END(),
+ };
+
+ memset(&opts, 0, sizeof(opts));
+ memset(&new, 0, sizeof(new));
+ opts.overwrite_ignore = 1;
+ opts.prefix = prefix;
+
+ opts.saved_argv = xmalloc(sizeof(const char *) * (argc + 2));
+ memcpy(opts.saved_argv, argv, sizeof(const char *) * (argc + 1));
+
+ 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);
+
+ /* recursive execution from checkout_new_worktree() */
+ opts.new_worktree_mode = getenv("GIT_CHECKOUT_NEW_WORKTREE") != NULL;
+ if (opts.new_worktree_mode)
+ opts.new_worktree = NULL;
+
+ if (!opts.new_worktree)
+ setup_work_tree();
+
+ if (conflict_style) {
+ opts.merge = 1; /* implied */
+ git_xmerge_config("merge.conflictstyle", conflict_style, NULL);
+ }
+
+ if ((!!opts.new_branch + !!opts.new_branch_force + !!opts.new_orphan_branch) > 1)
+ die(_("-b, -B and --orphan are mutually exclusive"));
+
+ /*
+ * 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/--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 -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 -b"));
+ 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) {
+ unsigned char rev[20];
+ int dwim_ok =
+ !opts.patch_mode &&
+ dwim_new_local_branch &&
+ opts.track == BRANCH_TRACK_UNSPECIFIED &&
+ !opts.new_branch;
+ int n = parse_branchname_arg(argc, argv, dwim_ok,
+ &new, &opts, rev);
+ argv += n;
+ argc -= n;
+ }
+
+ 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)
+ die(_("Cannot update paths and switch to branch '%s' at the same time.\n"
+ "Did you intend to checkout '%s' which can not be resolved as commit?"),
+ opts.new_branch, argv[0]);
+
+ if (opts.force_detach)
+ die(_("git checkout: --detach does not take a path argument '%s'"),
+ argv[0]);
+
+ 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."));
+ }
+
+ if (opts.new_branch) {
+ struct strbuf buf = STRBUF_INIT;
+
+ opts.branch_exists =
+ validate_new_branchname(opts.new_branch, &buf,
+ !!opts.new_branch_force,
+ !!opts.new_branch_force);
+
+ strbuf_release(&buf);
+ }
+
+ if (opts.patch_mode || opts.pathspec.nr)
+ return checkout_paths(&opts, new.name);
+ else
+ return checkout_branch(&opts, &new);
+}