From c17b229454ac3f5d20fd0cff3a663b03c13cb38e Mon Sep 17 00:00:00 2001 From: Junio C Hamano Date: Sun, 5 Jun 2011 22:17:04 -0700 Subject: [PATCH] checkout -b : correctly detect existing branch MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit When create a new branch, we fed "refs/heads/" as a string to get_sha1() and expected it to fail when a branch already exists. The right way to check if a ref exists is to check with resolve_ref(). A naïve solution that might appear attractive but does not work is to forbid slashes in get_describe_name() but that will not work. A describe name is is in the form of "ANYTHING-g", and that ANYTHING part comes from a original tag name used in the repository the user ran the describe command. A sick user could have a confusing hierarchical tag whose name is "refs/heads/foobar" (stored as refs/tags/refs/heads/foobar") to generate a describe name "refs/heads/foobar-6-g02ac983", and we should be able to use that name to refer to the object whose name is 02ac983. Signed-off-by: Junio C Hamano --- builtin/checkout.c | 2 +- refs.c | 6 ++++++ refs.h | 1 + t/t2018-checkout-branch.sh | 11 +++++++++++ 4 files changed, 19 insertions(+), 1 deletion(-) diff --git a/builtin/checkout.c b/builtin/checkout.c index 4ad74270c..88708d48b 100644 --- a/builtin/checkout.c +++ b/builtin/checkout.c @@ -874,7 +874,7 @@ no_reference: if (strbuf_check_branch_ref(&buf, opts.new_branch)) die("git checkout: we do not like '%s' as a branch name.", opts.new_branch); - if (!get_sha1(buf.buf, rev)) { + if (ref_exists(buf.buf)) { opts.branch_exists = 1; if (!opts.new_branch_force) die("git checkout: branch %s already exists", diff --git a/refs.c b/refs.c index 6f486ae62..92cd0d14c 100644 --- a/refs.c +++ b/refs.c @@ -1732,6 +1732,12 @@ int update_ref(const char *action, const char *refname, return 0; } +int ref_exists(char *refname) +{ + unsigned char sha1[20]; + return !!resolve_ref(refname, sha1, 1, NULL); +} + struct ref *find_ref_by_name(const struct ref *list, const char *name) { for ( ; list; list = list->next) diff --git a/refs.h b/refs.h index 762ce504b..070a7d9ca 100644 --- a/refs.h +++ b/refs.h @@ -46,6 +46,7 @@ extern void warn_dangling_symref(FILE *fp, const char *msg_fmt, const char *refn */ extern void add_extra_ref(const char *refname, const unsigned char *sha1, int flags); extern void clear_extra_refs(void); +extern int ref_exists(char *); extern int peel_ref(const char *, unsigned char *); diff --git a/t/t2018-checkout-branch.sh b/t/t2018-checkout-branch.sh index 1caffeac0..741d84257 100755 --- a/t/t2018-checkout-branch.sh +++ b/t/t2018-checkout-branch.sh @@ -163,4 +163,15 @@ test_expect_success 'checkout -f -B to an existing branch with mergeable changes test_must_fail test_dirty_mergeable ' +test_expect_success 'checkout -b ' ' + git tag -f -m "First commit" initial initial && + git checkout -f change1 && + name=$(git describe) && + git checkout -b $name && + git diff --exit-code change1 && + echo "refs/heads/$name" >expect && + git symbolic-ref HEAD >actual && + test_cmp expect actual +' + test_done -- 2.26.2