"git checkout --to" sets up a new working directory with a .git file pointing to $GIT_DIR/repos/<id>. It then executes "git checkout" again on the new worktree with the same arguments except "--to" is taken out. The second checkout execution, which is not contaminated with any info from the current repository, will actually check out and everything that normal "git checkout" does.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclo...@gmail.com> --- Documentation/git-checkout.txt | 34 +++++++++++++ Documentation/git.txt | 3 +- Documentation/gitrepository-layout.txt | 7 +++ builtin/checkout.c | 93 +++++++++++++++++++++++++++++++++- path.c | 2 +- t/t2025-checkout-to.sh (new +x) | 48 ++++++++++++++++++ 6 files changed, 183 insertions(+), 4 deletions(-) create mode 100755 t/t2025-checkout-to.sh diff --git a/Documentation/git-checkout.txt b/Documentation/git-checkout.txt index 33ad2ad..fcf73b2 100644 --- a/Documentation/git-checkout.txt +++ b/Documentation/git-checkout.txt @@ -225,6 +225,13 @@ This means that you can use `git checkout -p` to selectively discard edits from your current working tree. See the ``Interactive Mode'' section of linkgit:git-add[1] to learn how to operate the `--patch` mode. +--to=<path>:: + Check out a new branch in a separate working directory at + `<path>`. A new working directory is linked to the current + repository, sharing everything except working directory + specific files such as HEAD, index... See "MULTIPLE CHECKOUT + MODE" section for more information. + <branch>:: Branch to checkout; if it refers to a branch (i.e., a name that, when prepended with "refs/heads/", is a valid ref), then that @@ -388,6 +395,33 @@ $ git reflog -2 HEAD # or $ git log -g -2 HEAD ------------ +MULTIPLE CHECKOUT MODE +------------------------------- +Normally a working directory is attached to repository. When "git +checkout --to" is used, a new working directory is attached to the +current repository. This new working directory is called "linked +checkout" as compared to the "main checkout" prepared by "git init" or +"git clone". A repository has one main checkout and zero or more +linked checkouts. + +All checkouts share the same repository. Linked checkouts see the +repository a bit different from the main checkout. When the checkout +"new" reads the path $GIT_DIR/HEAD for example, the actual path +returned could be $GIT_DIR/repos/new/HEAD. This ensures checkouts +won't step on each other. + +Each linked checkout has a private space in $GIT_DIR/repos, usually +named after the base name of the working directory with a number added +to make it unique. The linked checkout's $GIT_DIR points to this +private space while $GIT_COMMON_DIR points to the main checkout's +$GIT_DIR. These settings are done by "git checkout --to". + +Because in this mode $GIT_DIR becomes a lightweight virtual file +system where a path could be rewritten to some place else, accessing +$GIT_DIR from scripts should use `git rev-parse --git-path` to resolve +a path instead of using it directly unless the path is known to be +private to the working directory. + EXAMPLES -------- diff --git a/Documentation/git.txt b/Documentation/git.txt index 749052f..c0a4940 100644 --- a/Documentation/git.txt +++ b/Documentation/git.txt @@ -792,7 +792,8 @@ Git so take care if using Cogito etc. If this variable is set to a path, non-worktree files that are normally in $GIT_DIR will be taken from this path instead. Worktree-specific files such as HEAD or index are - taken from $GIT_DIR. See linkgit:gitrepository-layout[5] for + taken from $GIT_DIR. See linkgit:gitrepository-layout[5] and + the section 'MULTIPLE CHECKOUT MODE' in linkgit:checkout[1] details. This variable has lower precedence than other path variables such as GIT_INDEX_FILE, GIT_OBJECT_DIRECTORY... diff --git a/Documentation/gitrepository-layout.txt b/Documentation/gitrepository-layout.txt index 0f341fc..543d874 100644 --- a/Documentation/gitrepository-layout.txt +++ b/Documentation/gitrepository-layout.txt @@ -249,6 +249,13 @@ modules:: directory is ignored if $GIT_COMMON_DIR is set and "$GIT_COMMON_DIR/modules" will be used instead. +repos:: + Contains worktree specific information of linked + checkouts. Each subdirectory contains the worktree-related + part of a linked checkout. This directory is ignored + $GIT_COMMON_DIR is set and "$GIT_COMMON_DIR/repos" will be + used instead. + SEE ALSO -------- linkgit:git-init[1], diff --git a/builtin/checkout.c b/builtin/checkout.c index 8023987..81adb74 100644 --- a/builtin/checkout.c +++ b/builtin/checkout.c @@ -48,6 +48,10 @@ struct checkout_opts { 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, @@ -250,6 +254,9 @@ static int checkout_paths(const struct checkout_opts *opts, 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); @@ -485,7 +492,7 @@ static int merge_working_tree(const struct checkout_opts *opts, topts.dir->flags |= DIR_SHOW_IGNORED; setup_standard_excludes(topts.dir); } - tree = parse_tree_indirect(old->commit ? + 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); @@ -796,7 +803,8 @@ static int switch_branches(const struct checkout_opts *opts, return ret; } - if (!opts->quiet && !old.path && old.commit && new->commit != old.commit) + 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); @@ -806,6 +814,74 @@ static int switch_branches(const struct checkout_opts *opts, return ret || writeout_error; } +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; + + if (!new->commit) + die(_("no branch specified")); + + 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("repos/%.*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; + if (mkdir(sb_repo.buf, 0777)) + die_errno(_("could not create directory of '%s'"), sb_repo.buf); + + 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); + + write_file(sb_git.buf, 1, "gitdir: %s/repos/%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_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; + return run_command(&cp); +} + static int git_checkout_config(const char *var, const char *value, void *cb) { if (!strcmp(var, "diff.ignoresubmodules")) { @@ -1067,6 +1143,9 @@ static int checkout_branch(struct checkout_opts *opts, 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; @@ -1109,6 +1188,8 @@ int cmd_checkout(int argc, const char **argv, const char *prefix) 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_STRING(0, "to", &opts.new_worktree, N_("path"), + N_("check a branch out in a separate working directory")), OPT_END(), }; @@ -1117,6 +1198,9 @@ int cmd_checkout(int argc, const char **argv, const char *prefix) 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); @@ -1125,6 +1209,11 @@ int cmd_checkout(int argc, const char **argv, const char *prefix) 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 (conflict_style) { opts.merge = 1; /* implied */ git_xmerge_config("merge.conflictstyle", conflict_style, NULL); diff --git a/path.c b/path.c index 8a6586c..e41d6b3 100644 --- a/path.c +++ b/path.c @@ -92,7 +92,7 @@ static void replace_dir(struct strbuf *buf, int len, const char *newdir) static const char *common_list[] = { "/branches", "/hooks", "/info", "/logs", "/lost-found", "/modules", - "/objects", "/refs", "/remotes", "/rr-cache", "/svn", + "/objects", "/refs", "/remotes", "/repos", "/rr-cache", "/svn", "config", "gc.pid", "packed-refs", "shallow", NULL }; diff --git a/t/t2025-checkout-to.sh b/t/t2025-checkout-to.sh new file mode 100755 index 0000000..5ec49e2 --- /dev/null +++ b/t/t2025-checkout-to.sh @@ -0,0 +1,48 @@ +#!/bin/sh + +test_description='test git checkout --to' + +. ./test-lib.sh + +test_expect_success 'setup' ' + test_commit init +' + +test_expect_success 'checkout --to not updating paths' ' + test_must_fail git checkout --to -- init.t +' + +test_expect_success 'checkout --to a new worktree' ' + git checkout --to here master && + ( + cd here && + test_cmp ../init.t init.t && + git symbolic-ref HEAD >actual && + echo refs/heads/master >expect && + test_cmp expect actual && + git fsck + ) +' + +test_expect_success 'checkout --to from a linked checkout' ' + ( + cd here && + git checkout --to nested-here master + cd nested-here && + git fsck + ) +' + +test_expect_success 'checkout --to a new worktree creating new branch' ' + git checkout --to there -b newmaster master && + ( + cd there && + test_cmp ../init.t init.t && + git symbolic-ref HEAD >actual && + echo refs/heads/newmaster >expect && + test_cmp expect actual && + git fsck + ) +' + +test_done -- 1.9.1.346.ga2b5940 -- To unsubscribe from this list: send the line "unsubscribe git" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html