peel: reject bad queries with EINVALIDSPECcmn/peeling-errors

There are some combination of objects and target types which we know
cannot be fulfilled. Return EINVALIDSPEC for those to signify that there
is a mismatch in the user-provided data and what the object model is
capable of satisfying.

If we start at a tag and in the course of peeling find out that we
cannot reach a particular type, we return EPEEL.

3 files changed, 30 insertions, 17 deletions

diff --git a/tests/object/peel.c b/tests/object/peel.c
index 6310388c4..344885f1d 100644
--- a/tests/object/peel.c
+++ b/tests/object/peel.c
@@ -63,28 +63,47 @@ void test_object_peel__peeling_an_object_into_its_own_type_returns_another_insta
 		"0266163a49e280c4f5ed1e08facd36a2bd716bcf", GIT_OBJ_BLOB);
 }
 
-void test_object_peel__can_peel_a_tag(void)
+void test_object_peel__tag(void)
 {
 	assert_peel("7b4384978d2493e851f9cca7858815fac9b10980", GIT_OBJ_COMMIT,
 		"e90810b8df3e80c413d903f631643c716887138d", GIT_OBJ_COMMIT);
 	assert_peel("7b4384978d2493e851f9cca7858815fac9b10980", GIT_OBJ_TREE,
 		"53fc32d17276939fc79ed05badaef2db09990016", GIT_OBJ_TREE);
+	assert_peel_error(GIT_EPEEL, "7b4384978d2493e851f9cca7858815fac9b10980", GIT_OBJ_BLOB);
+	assert_peel("7b4384978d2493e851f9cca7858815fac9b10980", GIT_OBJ_ANY,
+		    "e90810b8df3e80c413d903f631643c716887138d", GIT_OBJ_COMMIT);
 }
 
-void test_object_peel__can_peel_a_commit(void)
+void test_object_peel__commit(void)
 {
+	assert_peel_error(GIT_EINVALIDSPEC, "e90810b8df3e80c413d903f631643c716887138d", GIT_OBJ_BLOB);
 	assert_peel("e90810b8df3e80c413d903f631643c716887138d", GIT_OBJ_TREE,
-		"53fc32d17276939fc79ed05badaef2db09990016", GIT_OBJ_TREE);
+		    "53fc32d17276939fc79ed05badaef2db09990016", GIT_OBJ_TREE);
+	assert_peel("e90810b8df3e80c413d903f631643c716887138d", GIT_OBJ_COMMIT,
+		    "e90810b8df3e80c413d903f631643c716887138d", GIT_OBJ_COMMIT);
+	assert_peel_error(GIT_EINVALIDSPEC, "e90810b8df3e80c413d903f631643c716887138d", GIT_OBJ_TAG);
+	assert_peel("e90810b8df3e80c413d903f631643c716887138d", GIT_OBJ_ANY,
+		    "53fc32d17276939fc79ed05badaef2db09990016", GIT_OBJ_TREE);
 }
 
-void test_object_peel__cannot_peel_a_tree(void)
+void test_object_peel__tree(void)
 {
-	assert_peel_error(GIT_EAMBIGUOUS, "53fc32d17276939fc79ed05badaef2db09990016", GIT_OBJ_BLOB);
+	assert_peel_error(GIT_EINVALIDSPEC, "53fc32d17276939fc79ed05badaef2db09990016", GIT_OBJ_BLOB);
+	assert_peel("53fc32d17276939fc79ed05badaef2db09990016", GIT_OBJ_TREE,
+		    "53fc32d17276939fc79ed05badaef2db09990016", GIT_OBJ_TREE);
+	assert_peel_error(GIT_EINVALIDSPEC, "53fc32d17276939fc79ed05badaef2db09990016", GIT_OBJ_COMMIT);
+	assert_peel_error(GIT_EINVALIDSPEC, "53fc32d17276939fc79ed05badaef2db09990016", GIT_OBJ_TAG);
+	assert_peel_error(GIT_EINVALIDSPEC, "53fc32d17276939fc79ed05badaef2db09990016", GIT_OBJ_ANY);
 }
 
-void test_object_peel__cannot_peel_a_blob(void)
+void test_object_peel__blob(void)
 {
-	assert_peel_error(GIT_ENOTFOUND, "0266163a49e280c4f5ed1e08facd36a2bd716bcf", GIT_OBJ_COMMIT);
+	assert_peel("0266163a49e280c4f5ed1e08facd36a2bd716bcf", GIT_OBJ_BLOB,
+		    "0266163a49e280c4f5ed1e08facd36a2bd716bcf", GIT_OBJ_BLOB);
+	assert_peel_error(GIT_EINVALIDSPEC, "0266163a49e280c4f5ed1e08facd36a2bd716bcf", GIT_OBJ_TREE);
+	assert_peel_error(GIT_EINVALIDSPEC, "0266163a49e280c4f5ed1e08facd36a2bd716bcf", GIT_OBJ_COMMIT);
+	assert_peel_error(GIT_EINVALIDSPEC, "0266163a49e280c4f5ed1e08facd36a2bd716bcf", GIT_OBJ_TAG);
+	assert_peel_error(GIT_EINVALIDSPEC, "0266163a49e280c4f5ed1e08facd36a2bd716bcf", GIT_OBJ_ANY);
 }
 
 void test_object_peel__target_any_object_for_type_change(void)
@@ -96,10 +115,4 @@ void test_object_peel__target_any_object_for_type_change(void)
 	/* commit to tree */
 	assert_peel("e90810b8df3e80c413d903f631643c716887138d", GIT_OBJ_ANY,
 		"53fc32d17276939fc79ed05badaef2db09990016", GIT_OBJ_TREE);
-
-	/* fail to peel tree */
-	assert_peel_error(GIT_EAMBIGUOUS, "53fc32d17276939fc79ed05badaef2db09990016", GIT_OBJ_ANY);
-
-	/* fail to peel blob */
-	assert_peel_error(GIT_ENOTFOUND, "0266163a49e280c4f5ed1e08facd36a2bd716bcf", GIT_OBJ_ANY);
 }
diff --git a/tests/refs/peel.c b/tests/refs/peel.c
index 542694c47..83f6109c0 100644
--- a/tests/refs/peel.c
+++ b/tests/refs/peel.c
@@ -93,7 +93,7 @@ void test_refs_peel__can_peel_a_symbolic_reference(void)
 
 void test_refs_peel__cannot_peel_into_a_non_existing_target(void)
 {
-	assert_peel_error(GIT_ENOTFOUND, "refs/tags/point_to_blob", GIT_OBJ_TAG);
+	assert_peel_error(GIT_EINVALIDSPEC, "refs/tags/point_to_blob", GIT_OBJ_TAG);
 }
 
 void test_refs_peel__can_peel_into_any_non_tag_object(void)
diff --git a/tests/refs/revparse.c b/tests/refs/revparse.c
index a540f389d..94e55bda4 100644
--- a/tests/refs/revparse.c
+++ b/tests/refs/revparse.c
@@ -24,11 +24,11 @@ static void test_object_and_ref_inrepo(
 	error = git_revparse_ext(&obj, &ref, repo, spec);
 
 	if (expected_oid != NULL) {
-		cl_assert_equal_i(0, error);
+		cl_git_pass(error);
 		git_oid_fmt(objstr, git_object_id(obj));
 		cl_assert_equal_s(objstr, expected_oid);
 	} else
-		cl_assert_equal_i(GIT_ENOTFOUND, error);
+		cl_git_fail(error);
 
 	if (assert_reference_retrieval) {
 		if (expected_refname == NULL)
@@ -222,7 +222,7 @@ void test_refs_revparse__to_type(void)
 	assert_invalid_single_spec("wrapped_tag^{trip}");
 	test_object("point_to_blob^{commit}", NULL);
 	cl_assert_equal_i(
-		GIT_EAMBIGUOUS, git_revparse_single(&g_obj, g_repo, "wrapped_tag^{blob}"));
+		GIT_EPEEL, git_revparse_single(&g_obj, g_repo, "wrapped_tag^{blob}"));
 
 	test_object("wrapped_tag^{commit}", "a65fedf39aefe402d3bb6e24df4d4f5fe4547750");
 	test_object("wrapped_tag^{tree}", "944c0f6e4dfa41595e6eb3ceecdb14f50fe18162");