From 1806c29f2eb5f7e4b5952f4fcc75f2afe279f1a4 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Nguy=E1=BB=85n=20Th=C3=A1i=20Ng=E1=BB=8Dc=20Duy?= Date: Fri, 29 Mar 2019 17:39:16 +0700 Subject: switch: make --orphan switch to an empty tree MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Switching and creating branches always involves knowing the to begin the new branch from. Sometimes, people want to create a new branch that does not have any commits yet; --orphan is a flag to allow that. --orphan overrides the default of HEAD for instead causing us to start from an empty history with all tracked files removed from the index and working tree. The use of --orphan is incompatible with specifying a . A note on the implementation. An alternative is just create a dummy commit in-core with empty tree and switch to it. But there's a chance the commit's SHA-1 may end up somewhere permanent like reflog. It's best to make sure "commit" pointer is NULL to avoid it. Signed-off-by: Nguyễn Thái Ngọc Duy Signed-off-by: Junio C Hamano diff --git a/builtin/checkout.c b/builtin/checkout.c index 5f100c1..0351735 100644 --- a/builtin/checkout.c +++ b/builtin/checkout.c @@ -58,6 +58,7 @@ struct checkout_opts { int switch_branch_doing_nothing_is_ok; int only_merge_on_switching_branches; int can_switch_when_in_progress; + int orphan_from_empty_tree; const char *new_branch; const char *new_branch_force; @@ -568,15 +569,21 @@ static int merge_working_tree(const struct checkout_opts *opts, { int ret; struct lock_file lock_file = LOCK_INIT; + struct tree *new_tree; hold_locked_index(&lock_file, LOCK_DIE_ON_ERROR); if (read_cache_preload(NULL) < 0) return error(_("index file corrupt")); resolve_undo_clear(); + if (opts->new_orphan_branch && opts->orphan_from_empty_tree) { + if (new_branch_info->commit) + BUG("'switch --orphan' should never accept a commit as starting point"); + new_tree = parse_tree_indirect(the_hash_algo->empty_tree); + } else + new_tree = get_commit_tree(new_branch_info->commit); if (opts->discard_changes) { - ret = reset_tree(get_commit_tree(new_branch_info->commit), - opts, 1, writeout_error); + ret = reset_tree(new_tree, opts, 1, writeout_error); if (ret) return ret; } else { @@ -614,7 +621,8 @@ static int merge_working_tree(const struct checkout_opts *opts, &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); + parse_tree(new_tree); + tree = new_tree; init_tree_desc(&trees[1], tree->buffer, tree->size); ret = unpack_trees(2, trees, &topts); @@ -663,7 +671,7 @@ static int merge_working_tree(const struct checkout_opts *opts, o.verbosity = 0; work = write_tree_from_memory(&o); - ret = reset_tree(get_commit_tree(new_branch_info->commit), + ret = reset_tree(new_tree, opts, 1, writeout_error); if (ret) @@ -672,13 +680,13 @@ static int merge_working_tree(const struct checkout_opts *opts, o.branch1 = new_branch_info->name; o.branch2 = "local"; ret = merge_trees(&o, - get_commit_tree(new_branch_info->commit), + new_tree, work, get_commit_tree(old_branch_info->commit), &result); if (ret < 0) exit(128); - ret = reset_tree(get_commit_tree(new_branch_info->commit), + ret = reset_tree(new_tree, opts, 0, writeout_error); strbuf_release(&o.obuf); @@ -696,7 +704,7 @@ static int merge_working_tree(const struct checkout_opts *opts, if (write_locked_index(&the_index, &lock_file, COMMIT_LOCK)) die(_("unable to write new index file")); - if (!opts->discard_changes && !opts->quiet) + if (!opts->discard_changes && !opts->quiet && new_branch_info->commit) show_local_changes(&new_branch_info->commit->object, &opts->diff_options); return 0; @@ -897,7 +905,10 @@ static void orphaned_commit_warning(struct commit *old_commit, struct commit *ne 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 (new_commit) + add_pending_oid(&revs, "HEAD", + &new_commit->object.oid, + UNINTERESTING); if (prepare_revision_walk(&revs)) die(_("internal error in revision walk")); @@ -932,6 +943,14 @@ static int switch_branches(const struct checkout_opts *opts, if (old_branch_info.path) skip_prefix(old_branch_info.path, "refs/heads/", &old_branch_info.name); + if (opts->new_orphan_branch && opts->orphan_from_empty_tree) { + if (new_branch_info->name) + BUG("'switch --orphan' should never accept a commit as starting point"); + new_branch_info->commit = NULL; + new_branch_info->name = "(empty)"; + do_merge = 1; + } + if (!new_branch_info->name) { new_branch_info->name = "HEAD"; new_branch_info->commit = old_branch_info.commit; @@ -1268,6 +1287,8 @@ static int checkout_branch(struct checkout_opts *opts, if (opts->new_orphan_branch) { if (opts->track != BRANCH_TRACK_UNSPECIFIED) die(_("'%s' cannot be used with '%s'"), "--orphan", "-t"); + if (opts->orphan_from_empty_tree && new_branch_info->name) + die(_("'%s' cannot take "), "--orphan"); } else if (opts->force_detach) { if (opts->track != BRANCH_TRACK_UNSPECIFIED) die(_("'%s' cannot be used with '%s'"), "--detach", "-t"); @@ -1553,6 +1574,7 @@ int cmd_checkout(int argc, const char **argv, const char *prefix) opts.accept_pathspec = 1; opts.implicit_detach = 1; opts.can_switch_when_in_progress = 1; + opts.orphan_from_empty_tree = 0; options = parse_options_dup(checkout_options); options = add_common_options(&opts, options); @@ -1589,6 +1611,7 @@ int cmd_switch(int argc, const char **argv, const char *prefix) opts.only_merge_on_switching_branches = 1; opts.implicit_detach = 0; opts.can_switch_when_in_progress = 0; + opts.orphan_from_empty_tree = 1; options = parse_options_dup(switch_options); options = add_common_options(&opts, options); -- cgit v0.10.2-6-g49f6