From abe199808c6586047fb7255b80e3d17ffc26bf6c Mon Sep 17 00:00:00 2001 From: Junio C Hamano Date: Mon, 30 Jan 2012 12:10:08 -0800 Subject: [PATCH] git checkout -b: allow switching out of an unborn branch Running "git checkout -b another" immediately after "git init" when you do not even have a commit on 'master' fails with: $ git checkout -b another fatal: You are on a branch yet to be born This is unnecessary, if we redefine "git checkout -b $name" that does not take any $start_point (which has to be a commit) as "I want to check out a new branch $name from the state I am in". Signed-off-by: Junio C Hamano --- builtin/checkout.c | 19 +++++++++++++++++++ t/t2015-checkout-unborn.sh | 11 ++++++++++- 2 files changed, 29 insertions(+), 1 deletion(-) diff --git a/builtin/checkout.c b/builtin/checkout.c index 4c20dae34..b76e2c045 100644 --- a/builtin/checkout.c +++ b/builtin/checkout.c @@ -916,6 +916,17 @@ static int parse_branchname_arg(int argc, const char **argv, return argcount; } +static int switch_unborn_to_new_branch(struct checkout_opts *opts) +{ + int status; + struct strbuf branch_ref = STRBUF_INIT; + + strbuf_addf(&branch_ref, "refs/heads/%s", opts->new_branch); + status = create_symref("HEAD", branch_ref.buf, "checkout -b"); + strbuf_release(&branch_ref); + return status; +} + int cmd_checkout(int argc, const char **argv, const char *prefix) { struct checkout_opts opts; @@ -1089,5 +1100,13 @@ int cmd_checkout(int argc, const char **argv, const char *prefix) if (opts.writeout_stage) die(_("--ours/--theirs is incompatible with switching branches.")); + if (!new.commit) { + unsigned char rev[20]; + int flag; + + resolve_ref("HEAD", rev, 0, &flag); + if ((flag & REF_ISSYMREF) && is_null_sha1(rev)) + return switch_unborn_to_new_branch(&opts); + } return switch_branches(&opts, &new); } diff --git a/t/t2015-checkout-unborn.sh b/t/t2015-checkout-unborn.sh index c551d39a6..6352b74e2 100755 --- a/t/t2015-checkout-unborn.sh +++ b/t/t2015-checkout-unborn.sh @@ -1,6 +1,6 @@ #!/bin/sh -test_description='checkout from unborn branch protects contents' +test_description='checkout from unborn branch' . ./test-lib.sh test_expect_success 'setup' ' @@ -37,4 +37,13 @@ test_expect_success 'checkout from unborn merges identical index contents' ' git checkout -b new origin ' +test_expect_success 'checking out another branch from unborn state' ' + git checkout --orphan newroot && + git checkout -b anothername && + test_must_fail git show-ref --verify refs/heads/newroot && + git symbolic-ref HEAD >actual && + echo refs/heads/anothername >expect && + test_cmp expect actual +' + test_done -- 2.30.2