Merge branch 'uk/checkout-ambiguous-ref' into jch

* uk/checkout-ambiguous-ref:
  checkout: fix bug with ambiguous refs

diff --git a/builtin/checkout.c b/builtin/checkout.c
index 757f9a08ddbaf102726a781b06d7294a4638984e..d3cfaf0f45cea2c27dd8d7caf47ac43cd499c79e 100644 (file)
--- a/builtin/checkout.c
+++ b/builtin/checkout.c
@@ -678,7 +678,7 @@ static const char *unique_tracking_name(const char *name)
 int cmd_checkout(int argc, const char **argv, const char *prefix)
 {
        struct checkout_opts opts;
-       unsigned char rev[20];
+       unsigned char rev[20], branch_rev[20];
        const char *arg;
        struct branch_info new;
        struct tree *source_tree = NULL;
@@ -832,18 +832,21 @@ int cmd_checkout(int argc, const char **argv, const char *prefix)
                argc--;
 
                new.name = arg;
-               if ((new.commit = lookup_commit_reference_gently(rev, 1))) {
-                       setup_branch_path(&new);
+               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;
+               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 */
+
+               if (!(new.commit = lookup_commit_reference_gently(rev, 1))) {
+                       /* not a commit */
+                       source_tree = parse_tree_indirect(rev);
+               } else {
                        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);

diff --git a/t/t2019-checkout-amiguous-ref.sh b/t/t2019-checkout-amiguous-ref.sh
new file mode 100755 (executable)
index 0000000..943541d
--- /dev/null
+++ b/t/t2019-checkout-amiguous-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