Merge branch 'jc/maint-1.7.3-checkout-describe' into maint

* jc/maint-1.7.3-checkout-describe:
  checkout -b <name>: correctly detect existing branch

diff --git a/builtin/checkout.c b/builtin/checkout.c
index 28cdc51b85e7d433dca085c0080f964d19a391b4..af1e7b579a83aef15e11c0c5dfa29447e485654c 100644 (file)
--- a/builtin/checkout.c
+++ b/builtin/checkout.c
@@ -1071,7 +1071,7 @@ int cmd_checkout(int argc, const char **argv, const char *prefix)
                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 b10419a69815ef1c005915f3606c992659e60c77..3a8789d3857d17a3a0a94ba2750e9f22857b8667 100644 (file)
--- a/refs.c
+++ b/refs.c
@@ -1826,6 +1826,12 @@ 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 5e7a9a59f5f6b687d15eb37a11696433bdc8f15c..5de06e57e7a9644a7dd51832552e9d1afa53c8cd 100644 (file)
--- a/refs.h
+++ b/refs.h
@@ -54,6 +54,7 @@ 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 fa69016381b0196c49472af51e36948ec7c5a2a9..a42e03967b1df3001df24089f2c50008c092ac51 100755 (executable)
--- a/t/t2018-checkout-branch.sh
+++ b/t/t2018-checkout-branch.sh
@@ -169,4 +169,15 @@ test_expect_success 'checkout -f -B to an existing branch with mergeable changes
        test_must_fail test_dirty_mergeable
 '
 
+test_expect_success 'checkout -b <describe>' '
+       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