builtin/checkout: learn -B
Internally, --track and --orphan still use the 'safe' -b, not -B. Signed-off-by: Tay Ray Chuan <rctay89@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Tay Ray Chuan committed
Jun 24, 2010 at 03:29 UTC
02ac98374eefbe4a46d4b53a8a78057ad8ad39b7
3 files changed
+88
-7
Documentation/git-checkout.txt
+19
-2
@@ -9,7 +9,7 @@ SYNOPSIS
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--------
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[verse]
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'git checkout' [-q] [-f] [-m] [<branch>]
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-'git checkout' [-q] [-f] [-m] [[-b|--orphan] <new_branch>] [<start_point>]
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+'git checkout' [-q] [-f] [-m] [[-b|-B|--orphan] <new_branch>] [<start_point>]
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'git checkout' [-f|--ours|--theirs|-m|--conflict=<style>] [<tree-ish>] [--] <paths>...
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'git checkout' --patch [<tree-ish>] [--] [<paths>...]
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@@ -21,7 +21,7 @@ also update `HEAD` to set the specified branch as the current
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branch.
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'git checkout' [<branch>]::
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-'git checkout' -b <new branch> [<start point>]::
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+'git checkout' -b|-B <new_branch> [<start point>]::
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This form switches branches by updating the index, working
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tree, and HEAD to reflect the specified branch.
@@ -31,6 +31,17 @@ were called and then checked out; in this case you can
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use the `--track` or `--no-track` options, which will be passed to
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'git branch'. As a convenience, `--track` without `-b` implies branch
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creation; see the description of `--track` below.
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++
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+If `-B` is given, <new_branch> is created if it doesn't exist; otherwise, it
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+is reset. This is the transactional equivalent of
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++
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+------------
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+$ git branch -f <branch> [<start point>]
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+$ git checkout <branch>
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+------------
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++
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+that is to say, the branch is not reset/created unless "git checkout" is
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+successful.
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'git checkout' [--patch] [<tree-ish>] [--] <pathspec>...::
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@@ -75,6 +86,12 @@ entries; instead, unmerged entries are ignored.
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Create a new branch named <new_branch> and start it at
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<start_point>; see linkgit:git-branch[1] for details.
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+-B::
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+ Creates the branch <new_branch> and start it at <start_point>;
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+ if it already exists, then reset it to <start_point>. This is
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+ equivalent to running "git branch" with "-f"; see
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+ linkgit:git-branch[1] for details.
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+
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-t::
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--track::
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When creating a new branch, set up "upstream" configuration. See
builtin/checkout.c
+24
-5
@@ -32,7 +32,11 @@ struct checkout_opts {
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int writeout_stage;
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int writeout_error;
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+ /* not set by parse_options */
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+ int branch_exists;
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+
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const char *new_branch;
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+ const char *new_branch_force;
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const char *new_orphan_branch;
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int new_branch_log;
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enum branch_track track;
@@ -511,7 +515,8 @@ static void update_refs_for_switch(struct checkout_opts *opts,
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}
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}
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else
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- create_branch(old->name, opts->new_branch, new->name, 0,
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+ create_branch(old->name, opts->new_branch, new->name,
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+ opts->new_branch_force ? 1 : 0,
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opts->new_branch_log, opts->track);
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new->name = opts->new_branch;
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setup_branch_path(new);
@@ -531,7 +536,7 @@ static void update_refs_for_switch(struct checkout_opts *opts,
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new->name);
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else
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fprintf(stderr, "Switched to%s branch '%s'\n",
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- opts->new_branch ? " a new" : "",
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+ opts->branch_exists ? " and reset" : " a new",
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new->name);
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}
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if (old->path && old->name) {
@@ -659,6 +664,8 @@ int cmd_checkout(int argc, const char **argv, const char *prefix)
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OPT__QUIET(&opts.quiet),
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OPT_STRING('b', NULL, &opts.new_branch, "branch",
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"create and checkout a new branch"),
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+ OPT_STRING('B', NULL, &opts.new_branch_force, "branch",
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+ "create/reset and checkout a branch"),
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OPT_BOOLEAN('l', NULL, &opts.new_branch_log, "log for new branch"),
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OPT_SET_INT('t', "track", &opts.track, "track",
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BRANCH_TRACK_EXPLICIT),
@@ -689,6 +696,14 @@ int cmd_checkout(int argc, const char **argv, const char *prefix)
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argc = parse_options(argc, argv, prefix, options, checkout_usage,
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PARSE_OPT_KEEP_DASHDASH);
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+ /* we can assume from now on new_branch = !new_branch_force */
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+ if (opts.new_branch && opts.new_branch_force)
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+ die("-B cannot be used with -b");
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+
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+ /* copy -B over to -b, so that we can just check the latter */
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+ if (opts.new_branch_force)
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+ opts.new_branch = opts.new_branch_force;
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+
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if (patch_mode && (opts.track > 0 || opts.new_branch
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|| opts.new_branch_log || opts.merge || opts.force))
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die ("--patch is incompatible with all other options");
@@ -710,7 +725,7 @@ int cmd_checkout(int argc, const char **argv, const char *prefix)
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if (opts.new_orphan_branch) {
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if (opts.new_branch)
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- die("--orphan and -b are mutually exclusive");
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+ die("--orphan and -b|-B are mutually exclusive");
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if (opts.track > 0)
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die("--orphan cannot be used with -t");
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opts.new_branch = opts.new_orphan_branch;
@@ -859,8 +874,12 @@ no_reference:
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if (strbuf_check_branch_ref(&buf, opts.new_branch))
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die("git checkout: we do not like '%s' as a branch name.",
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opts.new_branch);
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- if (!get_sha1(buf.buf, rev))
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- die("git checkout: branch %s already exists", opts.new_branch);
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+ if (!get_sha1(buf.buf, rev)) {
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+ opts.branch_exists = 1;
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+ if (!opts.new_branch_force)
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+ die("git checkout: branch %s already exists",
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+ opts.new_branch);
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+ }
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strbuf_release(&buf);
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}
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t/t2018-checkout-branch.sh
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@@ -118,4 +118,49 @@ test_expect_success 'checkout -b to an existing branch fails' '
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test_must_fail do_checkout branch2 $HEAD2
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'
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+test_expect_success 'checkout -B to an existing branch resets branch to HEAD' '
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+ git checkout branch1 &&
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+
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+ do_checkout branch2 "" -B
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+'
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+
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+test_expect_success 'checkout -B to an existing branch with an explicit ref resets branch to that ref' '
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+ git checkout branch1 &&
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+
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+ do_checkout branch2 $HEAD1 -B
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+'
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+
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+test_expect_success 'checkout -B to an existing branch with unmergeable changes fails' '
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+ git checkout branch1 &&
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+
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+ setup_dirty_unmergeable &&
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+ test_must_fail do_checkout branch2 $HEAD1 -B &&
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+ test_dirty_unmergeable
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+'
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+
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+test_expect_success 'checkout -f -B to an existing branch with unmergeable changes discards changes' '
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+ # still dirty and on branch1
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+ do_checkout branch2 $HEAD1 "-f -B" &&
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+ test_must_fail test_dirty_unmergeable
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+'
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+
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+test_expect_success 'checkout -B to an existing branch preserves mergeable changes' '
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+ git checkout branch1 &&
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+
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+ setup_dirty_mergeable &&
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+ do_checkout branch2 $HEAD1 -B &&
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+ test_dirty_mergeable
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+'
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+
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+test_expect_success 'checkout -f -B to an existing branch with mergeable changes discards changes' '
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+ # clean up from previous test
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+ git reset --hard &&
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+
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+ git checkout branch1 &&
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+
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+ setup_dirty_mergeable &&
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+ do_checkout branch2 $HEAD1 "-f -B" &&
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+ test_must_fail test_dirty_mergeable
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+'
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+
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test_done