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-rw-r--r--builtin/checkout.c1521
1 files changed, 1521 insertions, 0 deletions
diff --git a/builtin/checkout.c b/builtin/checkout.c
new file mode 100644
index 0000000000..0e6037b296
--- /dev/null
+++ b/builtin/checkout.c
@@ -0,0 +1,1521 @@
+#define USE_THE_INDEX_COMPATIBILITY_MACROS
+#include "builtin.h"
+#include "config.h"
+#include "checkout.h"
+#include "lockfile.h"
+#include "parse-options.h"
+#include "refs.h"
+#include "object-store.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-config.h"
+#include "submodule.h"
+#include "advice.h"
+
+static int checkout_optimize_new_branch;
+
+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;
+ int show_progress;
+ int count_checkout_paths;
+ int overlay_mode;
+ /*
+ * If new checkout options are added, skip_merge_working_tree
+ * should be updated accordingly.
+ */
+
+ 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;
+};
+
+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 &&
+ 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;
+
+ 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]);
+
+ /*
+ * NEEDSWORK: re-create conflicts from merges with
+ * merge.renormalize set, too
+ */
+ status = ll_merge(&result_buf, path, &ancestor, "base",
+ &ours, "ours", &theirs, "theirs",
+ state->istate, 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. 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_paths(const struct checkout_opts *opts,
+ const char *revision)
+{
+ int pos;
+ struct checkout state = CHECKOUT_INIT;
+ static char *ps_matched;
+ struct object_id rev;
+ struct commit *head;
+ int errs = 0;
+ struct lock_file lock_file = LOCK_INIT;
+ int nr_checkouts = 0, nr_unmerged = 0;
+
+ 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->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->patch_mode)
+ return run_add_interactive(revision, "--patch=checkout",
+ &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, 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, 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 */
+ state.force = 1;
+ state.refresh_cache = 1;
+ state.istate = &the_index;
+
+ 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);
+ }
+
+ if (write_locked_index(&the_index, &lock_file, COMMIT_LOCK))
+ die(_("unable to write new index 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 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;
+ 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;
+ }
+}
+
+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, 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);
+}
+
+/*
+ * Skip merging the trees, updating the index and working directory if and
+ * only if we are creating a new branch via "git checkout -b <new_branch>."
+ */
+static int skip_merge_working_tree(const struct checkout_opts *opts,
+ const struct branch_info *old_branch_info,
+ const struct branch_info *new_branch_info)
+{
+ /*
+ * Do the merge if sparse checkout is on and the user has not opted in
+ * to the optimized behavior
+ */
+ if (core_apply_sparse_checkout && !checkout_optimize_new_branch)
+ return 0;
+
+ /*
+ * We must do the merge if we are actually moving to a new commit.
+ */
+ if (!old_branch_info->commit || !new_branch_info->commit ||
+ !oideq(&old_branch_info->commit->object.oid,
+ &new_branch_info->commit->object.oid))
+ return 0;
+
+ /*
+ * opts->patch_mode cannot be used with switching branches so is
+ * not tested here
+ */
+
+ /*
+ * opts->quiet only impacts output so doesn't require a merge
+ */
+
+ /*
+ * Honor the explicit request for a three-way merge or to throw away
+ * local changes
+ */
+ if (opts->merge || opts->force)
+ return 0;
+
+ /*
+ * --detach is documented as "updating the index and the files in the
+ * working tree" but this optimization skips those steps so fall through
+ * to the regular code path.
+ */
+ if (opts->force_detach)
+ return 0;
+
+ /*
+ * opts->writeout_stage cannot be used with switching branches so is
+ * not tested here
+ */
+
+ /*
+ * Honor the explicit ignore requests
+ */
+ if (!opts->overwrite_ignore || opts->ignore_skipworktree ||
+ opts->ignore_other_worktrees)
+ return 0;
+
+ /*
+ * opts->show_progress only impacts output so doesn't require a merge
+ */
+
+ /*
+ * opts->overlay_mode cannot be used with switching branches so is
+ * not tested here
+ */
+
+ /*
+ * If we aren't creating a new branch any changes or updates will
+ * happen in the existing branch. Since that could only be updating
+ * the index and working directory, we don't want to skip those steps
+ * or we've defeated any purpose in running the command.
+ */
+ if (!opts->new_branch)
+ return 0;
+
+ /*
+ * new_branch_force is defined to "create/reset and checkout a branch"
+ * so needs to go through the merge to do the reset
+ */
+ if (opts->new_branch_force)
+ return 0;
+
+ /*
+ * A new orphaned branch requrires the index and the working tree to be
+ * adjusted to <start_point>
+ */
+ if (opts->new_orphan_branch)
+ return 0;
+
+ /*
+ * Remaining variables are not checkout options but used to track state
+ */
+
+ /*
+ * Do the merge if this is the initial checkout. We cannot use
+ * is_cache_unborn() here because the index hasn't been loaded yet
+ * so cache_nr and timestamp.sec are always zero.
+ */
+ if (!file_exists(get_index_file()))
+ return 0;
+
+ return 1;
+}
+
+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;
+
+ 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->force) {
+ ret = reset_tree(get_commit_tree(new_branch_info->commit),
+ 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_branch_info->commit;
+ topts.verbose_update = opts->show_progress;
+ 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_branch_info->commit ?
+ &old_branch_info->commit->object.oid :
+ the_hash_algo->empty_tree);
+ init_tree_desc(&trees[0], tree->buffer, tree->size);
+ tree = parse_tree_indirect(&new_branch_info->commit->object.oid);
+ 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 *result;
+ struct tree *work;
+ struct merge_options o;
+ 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;
+
+ /* 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, the_repository);
+ o.verbosity = 0;
+ work = write_tree_from_memory(&o);
+
+ ret = reset_tree(get_commit_tree(new_branch_info->commit),
+ opts, 1,
+ writeout_error);
+ if (ret)
+ return ret;
+ o.ancestor = old_branch_info->name;
+ o.branch1 = new_branch_info->name;
+ o.branch2 = "local";
+ ret = merge_trees(&o,
+ get_commit_tree(new_branch_info->commit),
+ work,
+ get_commit_tree(old_branch_info->commit),
+ &result);
+ if (ret < 0)
+ exit(128);
+ ret = reset_tree(get_commit_tree(new_branch_info->commit),
+ opts, 0,
+ writeout_error);
+ strbuf_release(&o.obuf);
+ 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_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_insert(&msg, 0, reflog_msg, strlen(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);
+ 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);
+ 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;
+
+ 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 (!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);
+ }
+
+ /* optimize the "checkout -b <new_branch> path */
+ if (skip_merge_working_tree(opts, &old_branch_info, new_branch_info)) {
+ if (!checkout_optimize_new_branch && !opts->quiet) {
+ if (read_cache_preload(NULL) < 0)
+ return error(_("index file corrupt"));
+ show_local_changes(&new_branch_info->commit->object, &opts->diff_options);
+ }
+ } else {
+ 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, "checkout.optimizenewbranch")) {
+ checkout_optimize_new_branch = git_config_bool(var, value);
+ return 0;
+ }
+
+ 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 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,
+ int *dwim_remotes_matched)
+{
+ struct tree **source_tree = &opts->source_tree;
+ const char **new_branch = &opts->new_branch;
+ int argcount = 0;
+ struct object_id branch_rev;
+ 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;
+
+ 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);
+ 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" 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,
+ dwim_remotes_matched);
+ if (remote) {
+ if (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);
+ *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_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
+ 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);
+ }
+
+ 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(opts->prefix, 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;
+
+ 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 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)
+ 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->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_branch_info->name && !new_branch_info->commit)
+ die(_("Cannot switch branch to a non-commit '%s'"),
+ new_branch_info->name);
+
+ 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);
+}
+
+int cmd_checkout(int argc, const char **argv, const char *prefix)
+{
+ struct checkout_opts opts;
+ struct branch_info new_branch_info;
+ char *conflict_style = NULL;
+ int dwim_new_local_branch, no_dwim_new_local_branch = 0;
+ int dwim_remotes_matched = 0;
+ 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 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_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__FORCE(&opts.force, N_("force checkout (throw away local modifications)"),
+ PARSE_OPT_NOCOMPLETE),
+ OPT_BOOL('m', "merge", &opts.merge, N_("perform a 3-way merge with the new branch")),
+ OPT_BOOL_F(0, "overwrite-ignore", &opts.overwrite_ignore,
+ N_("update ignored files (default)"),
+ PARSE_OPT_NOCOMPLETE),
+ 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_BOOL(0, "no-guess", &no_dwim_new_local_branch,
+ N_("do not second guess 'git checkout <no-such-branch>'")),
+ OPT_BOOL(0, "ignore-other-worktrees", &opts.ignore_other_worktrees,
+ N_("do not check if another worktree is holding the given ref")),
+ { OPTION_CALLBACK, 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(0, "overlay", &opts.overlay_mode, N_("use overlay mode (default)")),
+ OPT_END(),
+ };
+
+ memset(&opts, 0, sizeof(opts));
+ memset(&new_branch_info, 0, sizeof(new_branch_info));
+ opts.overwrite_ignore = 1;
+ opts.prefix = prefix;
+ opts.show_progress = -1;
+ opts.overlay_mode = -1;
+
+ git_config(git_checkout_config, &opts);
+
+ opts.track = BRANCH_TRACK_UNSPECIFIED;
+
+ argc = parse_options(argc, argv, prefix, options, checkout_usage,
+ PARSE_OPT_KEEP_DASHDASH);
+
+ dwim_new_local_branch = !no_dwim_new_local_branch;
+ if (opts.show_progress < 0) {
+ if (opts.quiet)
+ opts.show_progress = 0;
+ else
+ opts.show_progress = isatty(2);
+ }
+
+ 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"));
+
+ if (opts.overlay_mode == 1 && opts.patch_mode)
+ die(_("-p and --overlay 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) {
+ struct object_id rev;
+ 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_branch_info, &opts, &rev,
+ &dwim_remotes_matched);
+ 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(_("'%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 (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;
+
+ 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) {
+ int ret = checkout_paths(&opts, new_branch_info.name);
+ if (ret && dwim_remotes_matched > 1 &&
+ advice_checkout_ambiguous_remote_branch_name)
+ advise(_("'%s' matched more than one remote tracking branch.\n"
+ "We found %d remotes with a reference that matched. So we fell back\n"
+ "on trying to resolve the argument as a path, but failed there too!\n"
+ "\n"
+ "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."),
+ argv[0],
+ dwim_remotes_matched);
+ return ret;
+ } else {
+ return checkout_branch(&opts, &new_branch_info);
+ }
+}