diff options
Diffstat (limited to 'builtin/checkout.c')
| -rw-r--r-- | builtin/checkout.c | 919 |
1 files changed, 919 insertions, 0 deletions
diff --git a/builtin/checkout.c b/builtin/checkout.c new file mode 100644 index 0000000000..757f9a08dd --- /dev/null +++ b/builtin/checkout.c @@ -0,0 +1,919 @@ +#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 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) +{ + 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(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++; + } + return error("path '%s' does not have %s version", + ce->name, + (stage == 2) ? "our" : "their"); +} + +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++; + } + return error("path '%s' does not have %s version", + ce->name, + (stage == 2) ? "our" : "their"); +} + +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(char *msg, struct commit *commit) +{ + struct strbuf sb = STRBUF_INIT; + struct pretty_print_context ctx = {0}; + parse_commit(commit); + pretty_print_commit(CMIT_FMT_ONELINE, commit, &sb, &ctx); + 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 : + (unsigned char *)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 (new->path) { + 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) + fprintf(stderr, "Switched to%s branch '%s'\n", + opts->branch_exists ? " and reset" : " a new", + 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); + } + } else if (strcmp(new->name, "HEAD")) { + 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); + } + } + remove_branch_state(); + strbuf_release(&msg); + if (!opts->quiet && (new->path || !strcmp(new->name, "HEAD"))) + report_tracking(new); +} + +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.commit = lookup_commit_reference_gently(rev, 1); + if (!(flag & REF_ISSYMREF)) + 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 we were on a detached HEAD, but have now moved to + * a new commit, we want to mention the old commit once more + * to remind the user that it might be lost. + */ + if (!opts->quiet && !old.path && old.commit && new->commit != old.commit) + describe_detached_head("Previous HEAD position was", old.commit); + + update_refs_for_switch(opts, &old, new); + + ret = post_checkout_hook(old.commit, new->commit, 1); + 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; +} + +int cmd_checkout(int argc, const char **argv, const char *prefix) +{ + struct checkout_opts opts; + unsigned char rev[20]; + const char *arg; + 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_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(), + }; + int has_dash_dash; + + 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)) + die ("--patch is incompatible with all other options"); + + /* --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"); + + /* + * 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 remote-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) { + if (!strcmp(argv[0], "--")) { /* case (2) */ + argv++; + argc--; + goto no_reference; + } + + 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 (!patch_mode && + dwim_new_local_branch && + opts.track == BRANCH_TRACK_UNSPECIFIED && + !opts.new_branch && + !check_filename(NULL, arg) && + argc == 1) { + const char *remote = unique_tracking_name(arg); + if (!remote || get_sha1(remote, rev)) + goto no_reference; + opts.new_branch = arg; + arg = remote; + /* DWIMmed to create local branch */ + } + else + goto no_reference; + } + + /* we can't end up being in (2) anymore, eat the argument */ + argv++; + argc--; + + new.name = arg; + if ((new.commit = lookup_commit_reference_gently(rev, 1))) { + setup_branch_path(&new); + + if ((check_ref_format(new.path) == CHECK_REF_FORMAT_OK) && + resolve_ref(new.path, rev, 1, NULL)) + ; + else + new.path = NULL; + parse_commit(new.commit); + source_tree = new.commit->tree; + } else + source_tree = parse_tree_indirect(rev); + + 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 { + argv++; + argc--; + } + } + +no_reference: + + 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 (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); +} |