sha1: tests should use hashes, not oid computation

The tests that examine sha1 behavior (including collision detection)
should test against the hash functionality directly, not indirectly
using the oid functions.

tests/core/sha1.c

@@ -13,7 +13,7 @@ void test_core_sha1__cleanup(void)
 	cl_fixture_cleanup(FIXTURE_DIR);
 }
 
-static int sha1_file(git_oid *out, const char *filename)
+static int sha1_file(unsigned char *out, const char *filename)
 {
 	git_hash_ctx ctx;
 	char buf[2048];
@@ -31,7 +31,7 @@ static int sha1_file(git_oid *out, const char *filename)
 	cl_assert_equal_i(0, read_len);
 	p_close(fd);
 
-	ret = git_hash_final(out->id, &ctx);
+	ret = git_hash_final(out, &ctx);
 	git_hash_ctx_cleanup(&ctx);
 
 	return ret;
@@ -39,26 +39,32 @@ static int sha1_file(git_oid *out, const char *filename)
 
 void test_core_sha1__sum(void)
 {
-	git_oid oid, expected;
+	unsigned char expected[GIT_HASH_SHA1_SIZE] = {
+		0x4e, 0x72, 0x67, 0x9e, 0x3e, 0xa4, 0xd0, 0x4e, 0x0c, 0x64,
+		0x2f, 0x02, 0x9e, 0x61, 0xeb, 0x80, 0x56, 0xc7, 0xed, 0x94
+	};
+	unsigned char actual[GIT_HASH_SHA1_SIZE];
 
-	cl_git_pass(sha1_file(&oid, FIXTURE_DIR "/hello_c"));
-	git_oid_fromstr(&expected, "4e72679e3ea4d04e0c642f029e61eb8056c7ed94");
-	cl_assert_equal_oid(&expected, &oid);
+	cl_git_pass(sha1_file(actual, FIXTURE_DIR "/hello_c"));
+	cl_assert_equal_i(0, memcmp(expected, actual, GIT_HASH_SHA1_SIZE));
 }
 
 /* test that sha1 collision detection works when enabled */
 void test_core_sha1__detect_collision_attack(void)
 {
-	git_oid oid, expected;
+	unsigned char actual[GIT_HASH_SHA1_SIZE];
+	unsigned char expected[GIT_HASH_SHA1_SIZE] = {
+		0x38, 0x76, 0x2c, 0xf7, 0xf5, 0x59, 0x34, 0xb3, 0x4d, 0x17,
+		0x9a, 0xe6, 0xa4, 0xc8, 0x0c, 0xad, 0xcc, 0xbb, 0x7f, 0x0a
+	};
 
 #ifdef GIT_SHA1_COLLISIONDETECT
 	GIT_UNUSED(&expected);
-	cl_git_fail(sha1_file(&oid, FIXTURE_DIR "/shattered-1.pdf"));
+	cl_git_fail(sha1_file(actual, FIXTURE_DIR "/shattered-1.pdf"));
 	cl_assert_equal_s("SHA1 collision attack detected", git_error_last()->message);
 #else
-	cl_git_pass(sha1_file(&oid, FIXTURE_DIR "/shattered-1.pdf"));
-	git_oid_fromstr(&expected, "38762cf7f55934b34d179ae6a4c80cadccbb7f0a");
-	cl_assert_equal_oid(&expected, &oid);
+	cl_git_pass(sha1_file(actual, FIXTURE_DIR "/shattered-1.pdf"));
+	cl_assert_equal_i(0, memcmp(expected, actual, GIT_HASH_SHA1_SIZE));
 #endif
 }