Commit b7ae71ecf263047c427be099a3e1536cca17dc5d
2014-02-05T11:47:33
refs: catch cases where the ref type has changed If the type of the on-disk reference has changed, the old value comparison should fail.
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diff --git a/src/refdb_fs.c b/src/refdb_fs.c
index c9f9c0f..ea758de 100644
--- a/src/refdb_fs.c
+++ b/src/refdb_fs.c
@@ -937,9 +937,21 @@ static int cmp_old_ref(int *cmp, git_refdb_backend *backend, const char *name,
git_reference *old_ref = NULL;
*cmp = 0;
- if (old_id || old_target) {
- if ((error = refdb_fs_backend__lookup(&old_ref, backend, name)) < 0)
- goto out;
+ /* It "matches" if there is no old value to compare against */
+ if (!old_id && !old_target)
+ return 0;
+
+ if ((error = refdb_fs_backend__lookup(&old_ref, backend, name)) < 0)
+ goto out;
+
+ /* If the types don't match, there's no way the values do */
+ if (old_id && old_ref->type != GIT_REF_OID) {
+ *cmp = -1;
+ goto out;
+ }
+ if (old_target && old_ref->type != GIT_REF_SYMBOLIC) {
+ *cmp = 1;
+ goto out;
}
if (old_id && old_ref->type == GIT_REF_OID)
diff --git a/tests/refs/races.c b/tests/refs/races.c
index 396f13d..02d57ef 100644
--- a/tests/refs/races.c
+++ b/tests/refs/races.c
@@ -92,3 +92,61 @@ void test_refs_races__delete(void)
git_reference_free(ref);
git_reference_free(ref2);
}
+
+void test_refs_races__switch_oid_to_symbolic(void)
+{
+ git_reference *ref, *ref2, *ref3;
+ git_oid id, other_id;
+
+ git_oid_fromstr(&id, commit_id);
+ git_oid_fromstr(&other_id, other_commit_id);
+
+ /* Removing a direct ref when it's currently symbolic should fail */
+ cl_git_pass(git_reference_lookup(&ref, g_repo, refname));
+ cl_git_pass(git_reference_symbolic_create(&ref2, g_repo, refname, other_refname, 1, NULL, NULL));
+ cl_git_fail_with(GIT_EMODIFIED, git_reference_delete(ref));
+
+ git_reference_free(ref);
+ git_reference_free(ref2);
+
+ cl_git_pass(git_reference_create(&ref, g_repo, refname, &id, 1, NULL, NULL));
+ git_reference_free(ref);
+
+ /* Updating a direct ref when it's currently symbolic should fail */
+ cl_git_pass(git_reference_lookup(&ref, g_repo, refname));
+ cl_git_pass(git_reference_symbolic_create(&ref2, g_repo, refname, other_refname, 1, NULL, NULL));
+ cl_git_fail_with(GIT_EMODIFIED, git_reference_set_target(&ref3, ref, &other_id, NULL, NULL));
+
+ git_reference_free(ref);
+ git_reference_free(ref2);
+ git_reference_free(ref3);
+}
+
+void test_refs_races__switch_symbolic_to_oid(void)
+{
+ git_reference *ref, *ref2, *ref3;
+ git_oid id, other_id;
+
+ git_oid_fromstr(&id, commit_id);
+ git_oid_fromstr(&other_id, other_commit_id);
+
+ /* Removing a symbolic ref when it's currently direct should fail */
+ cl_git_pass(git_reference_lookup(&ref, g_repo, "HEAD"));
+ cl_git_pass(git_reference_create(&ref2, g_repo, "HEAD", &id, 1, NULL, NULL));
+ cl_git_fail_with(GIT_EMODIFIED, git_reference_delete(ref));
+
+ git_reference_free(ref);
+ git_reference_free(ref2);
+
+ cl_git_pass(git_reference_symbolic_create(&ref, g_repo, "HEAD", refname, 1, NULL, NULL));
+ git_reference_free(ref);
+
+ /* Updating a symbolic ref when it's currently direct should fail */
+ cl_git_pass(git_reference_lookup(&ref, g_repo, "HEAD"));
+ cl_git_pass(git_reference_create(&ref2, g_repo, "HEAD", &id, 1, NULL, NULL));
+ cl_git_fail_with(GIT_EMODIFIED, git_reference_symbolic_set_target(&ref3, ref, other_refname, NULL, NULL));
+
+ git_reference_free(ref);
+ git_reference_free(ref2);
+ git_reference_free(ref3);
+}