diff options
| -rw-r--r-- | Documentation/git-checkout.txt | 13 | ||||
| -rw-r--r-- | builtin/checkout.c | 260 | ||||
| -rwxr-xr-x | t/t2019-checkout-ambiguous-ref.sh | 59 | ||||
| -rwxr-xr-x | t/t2020-checkout-detach.sh | 95 |
4 files changed, 320 insertions, 107 deletions
diff --git a/Documentation/git-checkout.txt b/Documentation/git-checkout.txt index 880763d..87863fc 100644 --- a/Documentation/git-checkout.txt +++ b/Documentation/git-checkout.txt @@ -9,6 +9,7 @@ SYNOPSIS -------- [verse] 'git checkout' [-q] [-f] [-m] [<branch>] +'git checkout' [-q] [-f] [-m] [--detach] [<commit>] 'git checkout' [-q] [-f] [-m] [[-b|-B|--orphan] <new_branch>] [<start_point>] 'git checkout' [-f|--ours|--theirs|-m|--conflict=<style>] [<tree-ish>] [--] <paths>... 'git checkout' --patch [<tree-ish>] [--] [<paths>...] @@ -22,9 +23,10 @@ branch. 'git checkout' [<branch>]:: 'git checkout' -b|-B <new_branch> [<start point>]:: +'git checkout' [--detach] [<commit>]:: This form switches branches by updating the index, working - tree, and HEAD to reflect the specified branch. + tree, and HEAD to reflect the specified branch or commit. + If `-b` is given, a new branch is created as if linkgit:git-branch[1] were called and then checked out; in this case you can @@ -115,6 +117,13 @@ explicitly give a name with '-b' in such a case. Create the new branch's reflog; see linkgit:git-branch[1] for details. +--detach:: + Rather than checking out a branch to work on it, check out a + commit for inspection and discardable experiments. + This is the default behavior of "git checkout <commit>" when + <commit> is not a branch name. See the "DETACHED HEAD" section + below for details. + --orphan:: Create a new 'orphan' branch, named <new_branch>, started from <start_point> and switch to it. The first commit made on this @@ -204,7 +213,7 @@ leave out at most one of `A` and `B`, in which case it defaults to `HEAD`. -Detached HEAD +DETACHED HEAD ------------- It is sometimes useful to be able to 'checkout' a commit that is diff --git a/builtin/checkout.c b/builtin/checkout.c index bef324e..cc97dbc 100644 --- a/builtin/checkout.c +++ b/builtin/checkout.c @@ -30,6 +30,7 @@ struct checkout_opts { int quiet; int merge; int force; + int force_detach; int writeout_stage; int writeout_error; @@ -541,7 +542,17 @@ static void update_refs_for_switch(struct checkout_opts *opts, strbuf_addf(&msg, "checkout: moving from %s to %s", old_desc ? old_desc : "(invalid)", new->name); - if (new->path) { + 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, 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); + } + } else if (new->path) { /* Switch branches. */ create_symref("HEAD", new->path, msg.buf); if (!opts->quiet) { if (old->path && !strcmp(new->path, old->path)) @@ -563,18 +574,11 @@ static void update_refs_for_switch(struct checkout_opts *opts, 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"))) + if (!opts->quiet && + (new->path || (!opts->force_detach && !strcmp(new->name, "HEAD")))) report_tracking(new); } @@ -675,11 +679,123 @@ static const char *unique_tracking_name(const char *name) return NULL; } +static int parse_branchname_arg(int argc, const char **argv, + int dwim_new_local_branch_ok, + struct branch_info *new, + struct tree **source_tree, + unsigned char rev[20], + const char **new_branch) +{ + int argcount = 0; + unsigned char branch_rev[20]; + const char *arg; + int has_dash_dash; + + /* + * 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 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) + return 0; + + if (!strcmp(argv[0], "--")) /* case (2) */ + return 1; + + 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 (dwim_new_local_branch_ok && + !check_filename(NULL, arg) && + argc == 1) { + const char *remote = unique_tracking_name(arg); + if (!remote || get_sha1(remote, rev)) + return argcount; + *new_branch = arg; + arg = remote; + /* DWIMmed to create local branch */ + } else { + 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_ref_format(new->path) == CHECK_REF_FORMAT_OK && + resolve_ref(new->path, branch_rev, 1, NULL)) + hashcpy(rev, branch_rev); + else + new->path = NULL; /* not an existing branch */ + + new->commit = lookup_commit_reference_gently(rev, 1); + if (!new->commit) { + /* not a commit */ + *source_tree = parse_tree_indirect(rev); + } else { + parse_commit(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 -> 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; +} + 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; @@ -692,6 +808,7 @@ int cmd_checkout(int argc, const char **argv, const char *prefix) 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_BOOLEAN(0, "detach", &opts.force_detach, "detach the HEAD at named commit"), 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"), @@ -709,7 +826,6 @@ int cmd_checkout(int argc, const char **argv, const char *prefix) PARSE_OPT_NOARG | PARSE_OPT_HIDDEN }, OPT_END(), }; - int has_dash_dash; memset(&opts, 0, sizeof(opts)); memset(&new, 0, sizeof(new)); @@ -731,9 +847,15 @@ int cmd_checkout(int argc, const char **argv, const char *prefix) opts.new_branch = opts.new_branch_force; if (patch_mode && (opts.track > 0 || opts.new_branch - || opts.new_branch_log || opts.merge || opts.force)) + || opts.new_branch_log || opts.merge || opts.force + || opts.force_detach)) die ("--patch is incompatible with all other options"); + if (opts.force_detach && (opts.new_branch || opts.new_orphan_branch)) + die("--detach cannot be used with -b/-B/--orphan"); + if (opts.force_detach && 0 < opts.track) + die("--detach cannot be used with -t"); + /* --track without -b should DWIM */ if (0 < opts.track && !opts.new_branch) { const char *argv0 = argv[0]; @@ -766,105 +888,30 @@ int cmd_checkout(int argc, const char **argv, const char *prefix) 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. + * Extract branch name from command line arguments, so + * all that is left is pathspecs. * - * 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. + * Handle * - * 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. + * 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) { - 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--; - } + int dwim_ok = + !patch_mode && + dwim_new_local_branch && + opts.track == BRANCH_TRACK_UNSPECIFIED && + !opts.new_branch; + int n = parse_branchname_arg(argc, argv, dwim_ok, + &new, &source_tree, rev, &opts.new_branch); + argv += n; + argc -= n; } -no_reference: - if (opts.track == BRANCH_TRACK_UNSPECIFIED) opts.track = git_branch_track; @@ -886,6 +933,9 @@ no_reference: } } + if (opts.force_detach) + die("git checkout: --detach does not take a path argument"); + 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."); diff --git a/t/t2019-checkout-ambiguous-ref.sh b/t/t2019-checkout-ambiguous-ref.sh new file mode 100755 index 0000000..943541d --- /dev/null +++ b/t/t2019-checkout-ambiguous-ref.sh @@ -0,0 +1,59 @@ +#!/bin/sh + +test_description='checkout handling of ambiguous (branch/tag) refs' +. ./test-lib.sh + +test_expect_success 'setup ambiguous refs' ' + test_commit branch file && + git branch ambiguity && + git branch vagueness && + test_commit tag file && + git tag ambiguity && + git tag vagueness HEAD:file && + test_commit other file +' + +test_expect_success 'checkout ambiguous ref succeeds' ' + git checkout ambiguity >stdout 2>stderr +' + +test_expect_success 'checkout produces ambiguity warning' ' + grep "warning.*ambiguous" stderr +' + +test_expect_success 'checkout chooses branch over tag' ' + echo refs/heads/ambiguity >expect && + git symbolic-ref HEAD >actual && + test_cmp expect actual && + echo branch >expect && + test_cmp expect file +' + +test_expect_success 'checkout reports switch to branch' ' + grep "Switched to branch" stderr && + ! grep "^HEAD is now at" stderr +' + +test_expect_success 'checkout vague ref succeeds' ' + git checkout vagueness >stdout 2>stderr && + test_set_prereq VAGUENESS_SUCCESS +' + +test_expect_success VAGUENESS_SUCCESS 'checkout produces ambiguity warning' ' + grep "warning.*ambiguous" stderr +' + +test_expect_success VAGUENESS_SUCCESS 'checkout chooses branch over tag' ' + echo refs/heads/vagueness >expect && + git symbolic-ref HEAD >actual && + test_cmp expect actual && + echo branch >expect && + test_cmp expect file +' + +test_expect_success VAGUENESS_SUCCESS 'checkout reports switch to branch' ' + grep "Switched to branch" stderr && + ! grep "^HEAD is now at" stderr +' + +test_done diff --git a/t/t2020-checkout-detach.sh b/t/t2020-checkout-detach.sh new file mode 100755 index 0000000..0042145 --- /dev/null +++ b/t/t2020-checkout-detach.sh @@ -0,0 +1,95 @@ +#!/bin/sh + +test_description='checkout into detached HEAD state' +. ./test-lib.sh + +check_detached () { + test_must_fail git symbolic-ref -q HEAD >/dev/null +} + +check_not_detached () { + git symbolic-ref -q HEAD >/dev/null +} + +reset () { + git checkout master && + check_not_detached +} + +test_expect_success 'setup' ' + test_commit one && + test_commit two && + git branch branch && + git tag tag +' + +test_expect_success 'checkout branch does not detach' ' + reset && + git checkout branch && + check_not_detached +' + +test_expect_success 'checkout tag detaches' ' + reset && + git checkout tag && + check_detached +' + +test_expect_success 'checkout branch by full name detaches' ' + reset && + git checkout refs/heads/branch && + check_detached +' + +test_expect_success 'checkout non-ref detaches' ' + reset && + git checkout branch^ && + check_detached +' + +test_expect_success 'checkout ref^0 detaches' ' + reset && + git checkout branch^0 && + check_detached +' + +test_expect_success 'checkout --detach detaches' ' + reset && + git checkout --detach branch && + check_detached +' + +test_expect_success 'checkout --detach without branch name' ' + reset && + git checkout --detach && + check_detached +' + +test_expect_success 'checkout --detach errors out for non-commit' ' + reset && + test_must_fail git checkout --detach one^{tree} && + check_not_detached +' + +test_expect_success 'checkout --detach errors out for extra argument' ' + reset && + git checkout master && + test_must_fail git checkout --detach tag one.t && + check_not_detached +' + +test_expect_success 'checkout --detached and -b are incompatible' ' + reset && + test_must_fail git checkout --detach -b newbranch tag && + check_not_detached +' + +test_expect_success 'checkout --detach moves HEAD' ' + reset && + git checkout one && + git checkout --detach two && + git diff --exit-code HEAD && + git diff --exit-code two +' + +test_done |