oid: define GIT_OID_SHA1_ZERO

Callers should not assume the layout of the oid structure; provide them
a macro that defines the null / zero sha1 object id.

examples/general.c

@@ -679,7 +679,7 @@ static void reference_listing(git_repository *repo)
 
 	for (i = 0; i < ref_list.count; ++i) {
 		git_reference *ref;
-		char oid_hex[GIT_OID_SHA1_HEXSIZE+1] = GIT_OID_HEX_ZERO;
+		char oid_hex[GIT_OID_SHA1_HEXSIZE+1] = GIT_OID_SHA1_HEXZERO;
 		const char *refname;
 
 		refname = ref_list.strings[i];

include/git2/common.h

@@ -106,11 +106,6 @@ GIT_BEGIN_DECL
 #define GIT_PATH_MAX 4096
 
 /**
- * The string representation of the null object ID.
- */
-#define GIT_OID_HEX_ZERO "0000000000000000000000000000000000000000"
-
-/**
  * Return the version of the libgit2 library
  * being currently used.
  *

include/git2/oid.h

@@ -36,6 +36,16 @@ typedef struct git_oid {
 } git_oid;
 
 /**
+ * The binary representation of the null object ID.
+ */
+#define GIT_OID_SHA1_ZERO { { 0 } }
+
+/**
+ * The string representation of the null object ID.
+ */
+#define GIT_OID_SHA1_HEXZERO "0000000000000000000000000000000000000000"
+
+/**
  * Parse a hex formatted object id into a git_oid.
  *
  * @param out oid structure the result is written into.

src/libgit2/merge.c

@@ -1061,7 +1061,7 @@ static int index_entry_similarity_calc(
 	const git_merge_options *opts)
 {
 	git_blob *blob;
-	git_diff_file diff_file = {{{0}}};
+	git_diff_file diff_file = { GIT_OID_SHA1_ZERO };
 	git_object_size_t blobsize;
 	int error;
 

src/libgit2/object.c

@@ -230,7 +230,7 @@ int git_object_lookup_prefix(
 			error = git_odb_read(&odb_obj, odb, id);
 		}
 	} else {
-		git_oid short_oid = {{ 0 }};
+		git_oid short_oid = GIT_OID_SHA1_ZERO;
 
 		git_oid__cpy_prefix(&short_oid, id, len);
 
@@ -502,7 +502,7 @@ static int git_object__short_id(git_str *out, const git_object *obj)
 {
 	git_repository *repo;
 	int len = GIT_ABBREV_DEFAULT, error;
-	git_oid id = {{0}};
+	git_oid id = GIT_OID_SHA1_ZERO;
 	git_odb *odb;
 
 	GIT_ASSERT_ARG(out);

src/libgit2/odb.c

@@ -914,7 +914,7 @@ static int odb_exists_prefix_1(git_oid *out, git_odb *db,
 {
 	size_t i;
 	int error = GIT_ENOTFOUND, num_found = 0;
-	git_oid last_found = {{0}}, found;
+	git_oid last_found = GIT_OID_SHA1_ZERO, found;
 
 	if ((error = git_mutex_lock(&db->lock)) < 0) {
 		git_error_set(GIT_ERROR_ODB, "failed to acquire the odb lock");
@@ -965,7 +965,7 @@ int git_odb_exists_prefix(
 	git_oid *out, git_odb *db, const git_oid *short_id, size_t len)
 {
 	int error;
-	git_oid key = {{0}};
+	git_oid key = GIT_OID_SHA1_ZERO;
 
 	GIT_ASSERT_ARG(db);
 	GIT_ASSERT_ARG(short_id);
@@ -1305,7 +1305,7 @@ static int read_prefix_1(git_odb_object **out, git_odb *db,
 {
 	size_t i;
 	int error = 0;
-	git_oid found_full_oid = {{0}};
+	git_oid found_full_oid = GIT_OID_SHA1_ZERO;
 	git_rawobj raw = {0};
 	void *data = NULL;
 	bool found = false;
@@ -1391,7 +1391,7 @@ out:
 int git_odb_read_prefix(
 	git_odb_object **out, git_odb *db, const git_oid *short_id, size_t len)
 {
-	git_oid key = {{0}};
+	git_oid key = GIT_OID_SHA1_ZERO;
 	int error;
 
 	GIT_ASSERT_ARG(out);

src/libgit2/odb_pack.c

@@ -307,7 +307,7 @@ static int pack_entry_find_prefix(
 {
 	int error;
 	size_t i;
-	git_oid found_full_oid = {{0}};
+	git_oid found_full_oid = GIT_OID_SHA1_ZERO;
 	bool found = false;
 	struct git_pack_file *last_found = backend->last_found, *p;
 	git_midx_entry midx_entry;

src/libgit2/refdb_fs.c

@@ -2192,7 +2192,7 @@ success:
 static int reflog_append(refdb_fs_backend *backend, const git_reference *ref, const git_oid *old, const git_oid *new, const git_signature *who, const char *message)
 {
 	int error, is_symbolic, open_flags;
-	git_oid old_id = {{0}}, new_id = {{0}};
+	git_oid old_id = GIT_OID_SHA1_ZERO, new_id = GIT_OID_SHA1_ZERO;
 	git_str buf = GIT_STR_INIT, path = GIT_STR_INIT;
 	git_repository *repo = backend->repo;
 

src/libgit2/reflog.c

@@ -104,7 +104,7 @@ int git_reflog_append(git_reflog *reflog, const git_oid *new_oid, const git_sign
 	previous = git_reflog_entry_byindex(reflog, 0);
 
 	if (previous == NULL)
-		git_oid_fromstr(&entry->oid_old, GIT_OID_HEX_ZERO);
+		git_oid_fromstr(&entry->oid_old, GIT_OID_SHA1_HEXZERO);
 	else
 		git_oid_cpy(&entry->oid_old, &previous->oid_cur);
 
@@ -219,7 +219,7 @@ int git_reflog_drop(git_reflog *reflog, size_t idx, int rewrite_previous_entry)
 	/* If the oldest entry has just been removed... */
 	if (idx == entrycount - 1) {
 		/* ...clear the oid_old member of the "new" oldest entry */
-		if (git_oid_fromstr(&entry->oid_old, GIT_OID_HEX_ZERO) < 0)
+		if (git_oid_fromstr(&entry->oid_old, GIT_OID_SHA1_HEXZERO) < 0)
 			return -1;
 
 		return 0;

src/libgit2/remote.c

@@ -1622,7 +1622,7 @@ int git_remote_prune(git_remote *remote, const git_remote_callbacks *callbacks)
 	const git_refspec *spec;
 	const char *refname;
 	int error;
-	git_oid zero_id = {{ 0 }};
+	git_oid zero_id = GIT_OID_SHA1_ZERO;
 
 	if (callbacks)
 		GIT_ERROR_CHECK_VERSION(callbacks, GIT_REMOTE_CALLBACKS_VERSION, "git_remote_callbacks");

tests/libgit2/blame/getters.c

@@ -10,11 +10,11 @@ void test_blame_getters__initialize(void)
 	git_blame_options opts = GIT_BLAME_OPTIONS_INIT;
 
 	git_blame_hunk hunks[] = {
-		{ 3, {{0}},  1, NULL, {{0}}, "a", 0},
-		{ 3, {{0}},  4, NULL, {{0}}, "b", 0},
-		{ 3, {{0}},  7, NULL, {{0}}, "c", 0},
-		{ 3, {{0}}, 10, NULL, {{0}}, "d", 0},
-		{ 3, {{0}}, 13, NULL, {{0}}, "e", 0},
+		{ 3, GIT_OID_SHA1_ZERO,  1, NULL, GIT_OID_SHA1_ZERO, "a", 0},
+		{ 3, GIT_OID_SHA1_ZERO,  4, NULL, GIT_OID_SHA1_ZERO, "b", 0},
+		{ 3, GIT_OID_SHA1_ZERO,  7, NULL, GIT_OID_SHA1_ZERO, "c", 0},
+		{ 3, GIT_OID_SHA1_ZERO, 10, NULL, GIT_OID_SHA1_ZERO, "d", 0},
+		{ 3, GIT_OID_SHA1_ZERO, 13, NULL, GIT_OID_SHA1_ZERO, "e", 0},
 	};
 
 	g_blame = git_blame__alloc(NULL, opts, "");

tests/libgit2/core/oidmap.c

@@ -93,9 +93,9 @@ void test_core_oidmap__get_fails_with_nonexisting_key(void)
 void test_core_oidmap__setting_oid_persists(void)
 {
 	git_oid oids[] = {
-	    {{ 0x01 }},
-	    {{ 0x02 }},
-	    {{ 0x03 }}
+	    { { 0x01 }},
+	    { { 0x02 }},
+	    { { 0x03 }}
 	};
 
 	cl_git_pass(git_oidmap_set(g_map, &oids[0], "one"));
@@ -110,9 +110,9 @@ void test_core_oidmap__setting_oid_persists(void)
 void test_core_oidmap__setting_existing_key_updates(void)
 {
 	git_oid oids[] = {
-	    {{ 0x01 }},
-	    {{ 0x02 }},
-	    {{ 0x03 }}
+	    { { 0x01 }},
+	    { { 0x02 }},
+	    { { 0x03 }}
 	};
 
 	cl_git_pass(git_oidmap_set(g_map, &oids[0], "one"));

tests/libgit2/iterator/workdir.c

@@ -1481,7 +1481,7 @@ void test_iterator_workdir__hash_when_requested(void)
 	git_iterator *iter;
 	const git_index_entry *entry;
 	git_iterator_options iter_opts = GIT_ITERATOR_OPTIONS_INIT;
-	git_oid expected_id = {{0}};
+	git_oid expected_id = GIT_OID_SHA1_ZERO;
 	size_t i;
 
 	struct merge_index_entry expected[] = {

tests/libgit2/object/tree/update.c

@@ -21,7 +21,7 @@ void test_object_tree_update__remove_blob(void)
 	const char *path = "README";
 
 	git_tree_update updates[] = {
-		{ GIT_TREE_UPDATE_REMOVE, {{0}}, GIT_FILEMODE_BLOB /* ignored */, path},
+		{ GIT_TREE_UPDATE_REMOVE, GIT_OID_SHA1_ZERO, GIT_FILEMODE_BLOB /* ignored */, path},
 	};
 
 	cl_git_pass(git_oid_fromstr(&base_id, "c4dc1555e4d4fa0e0c9c3fc46734c7c35b3ce90b"));
@@ -50,7 +50,7 @@ void test_object_tree_update__remove_blob_deeper(void)
 	const char *path = "subdir/README";
 
 	git_tree_update updates[] = {
-		{ GIT_TREE_UPDATE_REMOVE, {{0}}, GIT_FILEMODE_BLOB /* ignored */, path},
+		{ GIT_TREE_UPDATE_REMOVE, GIT_OID_SHA1_ZERO, GIT_FILEMODE_BLOB /* ignored */, path},
 	};
 
 	cl_git_pass(git_oid_fromstr(&base_id, "c4dc1555e4d4fa0e0c9c3fc46734c7c35b3ce90b"));
@@ -80,8 +80,8 @@ void test_object_tree_update__remove_all_entries(void)
 	const char *path2 = "subdir/subdir2/new.txt";
 
 	git_tree_update updates[] = {
-		{ GIT_TREE_UPDATE_REMOVE, {{0}}, GIT_FILEMODE_BLOB /* ignored */, path1},
-		{ GIT_TREE_UPDATE_REMOVE, {{0}}, GIT_FILEMODE_BLOB /* ignored */, path2},
+		{ GIT_TREE_UPDATE_REMOVE, GIT_OID_SHA1_ZERO, GIT_FILEMODE_BLOB /* ignored */, path1},
+		{ GIT_TREE_UPDATE_REMOVE, GIT_OID_SHA1_ZERO, GIT_FILEMODE_BLOB /* ignored */, path2},
 	};
 
 	cl_git_pass(git_oid_fromstr(&base_id, "c4dc1555e4d4fa0e0c9c3fc46734c7c35b3ce90b"));
@@ -112,7 +112,7 @@ void test_object_tree_update__replace_blob(void)
 	git_index_entry entry = { {0} };
 
 	git_tree_update updates[] = {
-		{ GIT_TREE_UPDATE_UPSERT, {{0}}, GIT_FILEMODE_BLOB, path},
+		{ GIT_TREE_UPDATE_UPSERT, GIT_OID_SHA1_ZERO, GIT_FILEMODE_BLOB, path},
 	};
 
 	cl_git_pass(git_oid_fromstr(&base_id, "c4dc1555e4d4fa0e0c9c3fc46734c7c35b3ce90b"));
@@ -153,9 +153,9 @@ void test_object_tree_update__add_blobs(void)
 	};
 
 	git_tree_update updates[] = {
-		{ GIT_TREE_UPDATE_UPSERT, {{0}}, GIT_FILEMODE_BLOB, paths[0]},
-		{ GIT_TREE_UPDATE_UPSERT, {{0}}, GIT_FILEMODE_BLOB, paths[1]},
-		{ GIT_TREE_UPDATE_UPSERT, {{0}}, GIT_FILEMODE_BLOB, paths[2]},
+		{ GIT_TREE_UPDATE_UPSERT, GIT_OID_SHA1_ZERO, GIT_FILEMODE_BLOB, paths[0]},
+		{ GIT_TREE_UPDATE_UPSERT, GIT_OID_SHA1_ZERO, GIT_FILEMODE_BLOB, paths[1]},
+		{ GIT_TREE_UPDATE_UPSERT, GIT_OID_SHA1_ZERO, GIT_FILEMODE_BLOB, paths[2]},
 	};
 
 	cl_git_pass(git_oid_fromstr(&base_id, "c4dc1555e4d4fa0e0c9c3fc46734c7c35b3ce90b"));
@@ -210,9 +210,9 @@ void test_object_tree_update__add_blobs_unsorted(void)
 	};
 
 	git_tree_update updates[] = {
-		{ GIT_TREE_UPDATE_UPSERT, {{0}}, GIT_FILEMODE_BLOB, paths[0]},
-		{ GIT_TREE_UPDATE_UPSERT, {{0}}, GIT_FILEMODE_BLOB, paths[1]},
-		{ GIT_TREE_UPDATE_UPSERT, {{0}}, GIT_FILEMODE_BLOB, paths[2]},
+		{ GIT_TREE_UPDATE_UPSERT, GIT_OID_SHA1_ZERO, GIT_FILEMODE_BLOB, paths[0]},
+		{ GIT_TREE_UPDATE_UPSERT, GIT_OID_SHA1_ZERO, GIT_FILEMODE_BLOB, paths[1]},
+		{ GIT_TREE_UPDATE_UPSERT, GIT_OID_SHA1_ZERO, GIT_FILEMODE_BLOB, paths[2]},
 	};
 
 	cl_git_pass(git_oid_fromstr(&base_id, "c4dc1555e4d4fa0e0c9c3fc46734c7c35b3ce90b"));
@@ -258,8 +258,8 @@ void test_object_tree_update__add_conflict(void)
 	int i;
 	git_oid tree_updater_id;
 	git_tree_update updates[] = {
-		{ GIT_TREE_UPDATE_UPSERT, {{0}}, GIT_FILEMODE_BLOB, "a/dir/blob"},
-		{ GIT_TREE_UPDATE_UPSERT, {{0}}, GIT_FILEMODE_BLOB, "a/dir"},
+		{ GIT_TREE_UPDATE_UPSERT, GIT_OID_SHA1_ZERO, GIT_FILEMODE_BLOB, "a/dir/blob"},
+		{ GIT_TREE_UPDATE_UPSERT, GIT_OID_SHA1_ZERO, GIT_FILEMODE_BLOB, "a/dir"},
 	};
 
 	for (i = 0; i < 2; i++) {
@@ -274,8 +274,8 @@ void test_object_tree_update__add_conflict2(void)
 	int i;
 	git_oid tree_updater_id;
 	git_tree_update updates[] = {
-		{ GIT_TREE_UPDATE_UPSERT, {{0}}, GIT_FILEMODE_BLOB, "a/dir/blob"},
-		{ GIT_TREE_UPDATE_UPSERT, {{0}}, GIT_FILEMODE_TREE, "a/dir/blob"},
+		{ GIT_TREE_UPDATE_UPSERT, GIT_OID_SHA1_ZERO, GIT_FILEMODE_BLOB, "a/dir/blob"},
+		{ GIT_TREE_UPDATE_UPSERT, GIT_OID_SHA1_ZERO, GIT_FILEMODE_TREE, "a/dir/blob"},
 	};
 
 	for (i = 0; i < 2; i++) {
@@ -290,7 +290,7 @@ void test_object_tree_update__remove_invalid_submodule(void)
 	git_tree *baseline;
 	git_oid updated_tree_id, baseline_id;
 	git_tree_update updates[] = {
-		{GIT_TREE_UPDATE_REMOVE, {{0}}, GIT_FILEMODE_BLOB, "submodule"},
+		{GIT_TREE_UPDATE_REMOVE, GIT_OID_SHA1_ZERO, GIT_FILEMODE_BLOB, "submodule"},
 	};
 
 	/* This tree contains a submodule with an all-zero commit for a submodule named 'submodule' */

tests/libgit2/object/tree/write.c

@@ -516,7 +516,7 @@ void test_object_tree_write__object_validity(void)
 void test_object_tree_write__invalid_null_oid(void)
 {
 	git_treebuilder *bld;
-	git_oid null_oid = {{0}};
+	git_oid null_oid = GIT_OID_SHA1_ZERO;
 
 	cl_git_pass(git_treebuilder_new(&bld, g_repo, NULL));
 	cl_git_fail(git_treebuilder_insert(NULL, bld, "null_oid_file", &null_oid, GIT_FILEMODE_BLOB));

tests/libgit2/odb/backend/simple.c

@@ -237,7 +237,7 @@ void test_odb_backend_simple__null_oid_is_ignored(void)
 		{ "0000000000000000000000000000000000000000", "null oid content" },
 		{ NULL, NULL }
 	};
-	git_oid null_oid = {{0}};
+	git_oid null_oid = GIT_OID_SHA1_ZERO;
 	git_odb_object *obj;
 
 	setup_backend(objs);

tests/libgit2/odb/mixed.c

@@ -186,7 +186,7 @@ static void assert_found_objects(git_odb_expand_id *ids)
 	num = ARRAY_SIZE(expand_id_test_data);
 
 	for (i = 0; i < num; i++) {
-		git_oid expected_id = {{0}};
+		git_oid expected_id = GIT_OID_SHA1_ZERO;
 		size_t expected_len = 0;
 		git_object_t expected_type = 0;
 
@@ -204,7 +204,7 @@ static void assert_found_objects(git_odb_expand_id *ids)
 
 static void assert_notfound_objects(git_odb_expand_id *ids)
 {
-	git_oid expected_id = {{0}};
+	git_oid expected_id = GIT_OID_SHA1_ZERO;
 	size_t num, i;
 
 	num = ARRAY_SIZE(expand_id_test_data);

tests/libgit2/online/clone.c

@@ -629,7 +629,7 @@ void test_online_clone__ssh_cannot_change_username(void)
 static int ssh_certificate_check(git_cert *cert, int valid, const char *host, void *payload)
 {
 	git_cert_hostkey *key;
-	git_oid expected = {{0}}, actual = {{0}};
+	git_oid expected = GIT_OID_SHA1_ZERO, actual = GIT_OID_SHA1_ZERO;
 
 	GIT_UNUSED(valid);
 	GIT_UNUSED(payload);

tests/libgit2/online/push_util.c

@@ -2,8 +2,6 @@
 #include "vector.h"
 #include "push_util.h"
 
-const git_oid OID_ZERO = {{ 0 }};
-
 void updated_tip_free(updated_tip *t)
 {
 	git__free(t->name);

tests/libgit2/refs/branches/delete.c

@@ -119,7 +119,7 @@ void test_refs_branches_delete__removes_reflog(void)
 {
 	git_reference *branch;
 	git_reflog *log;
-	git_oid oidzero = {{0}};
+	git_oid oidzero = GIT_OID_SHA1_ZERO;
 	git_signature *sig;
 
 	/* Ensure the reflog has at least one entry */
@@ -150,7 +150,7 @@ void test_refs_branches_delete__removes_empty_folders(void)
 	git_reference *branch;
 
 	git_reflog *log;
-	git_oid oidzero = {{0}};
+	git_oid oidzero = GIT_OID_SHA1_ZERO;
 	git_signature *sig;
 
 	git_str ref_folder = GIT_STR_INIT;

tests/libgit2/refs/reflog/drop.c

@@ -70,7 +70,7 @@ void test_refs_reflog_drop__can_drop_the_oldest_entry(void)
 	cl_assert_equal_sz(entrycount - 1, git_reflog_entrycount(g_reflog));
 
 	entry = git_reflog_entry_byindex(g_reflog, entrycount - 2);
-	cl_assert(git_oid_streq(&entry->oid_old, GIT_OID_HEX_ZERO) != 0);
+	cl_assert(git_oid_streq(&entry->oid_old, GIT_OID_SHA1_HEXZERO) != 0);
 }
 
 void test_refs_reflog_drop__can_drop_the_oldest_entry_and_rewrite_the_log_history(void)
@@ -83,7 +83,7 @@ void test_refs_reflog_drop__can_drop_the_oldest_entry_and_rewrite_the_log_histor
 	cl_assert_equal_sz(entrycount - 1, git_reflog_entrycount(g_reflog));
 
 	entry = git_reflog_entry_byindex(g_reflog, entrycount - 2);
-	cl_assert(git_oid_streq(&entry->oid_old, GIT_OID_HEX_ZERO) == 0);
+	cl_assert(git_oid_streq(&entry->oid_old, GIT_OID_SHA1_HEXZERO) == 0);
 }
 
 void test_refs_reflog_drop__can_drop_all_the_entries(void)

tests/libgit2/refs/reflog/messages.c

@@ -264,7 +264,7 @@ void test_refs_reflog_messages__creating_a_direct_reference(void)
 	cl_assert_equal_sz(1, git_reflog_entrycount(reflog));
 
 	entry = git_reflog_entry_byindex(reflog, 0);
-	cl_assert(git_oid_streq(&entry->oid_old, GIT_OID_HEX_ZERO) == 0);
+	cl_assert(git_oid_streq(&entry->oid_old, GIT_OID_SHA1_HEXZERO) == 0);
 	cl_assert_equal_oid(&id, &entry->oid_cur);
 	cl_assert_equal_s(message, entry->msg);
 
@@ -352,7 +352,7 @@ void test_refs_reflog_messages__creating_branches_default_messages(void)
 
 	cl_git_pass(git_str_printf(&buf, "branch: Created from %s", git_oid_tostr_s(git_commit_id(target))));
 	cl_reflog_check_entry(g_repo, "refs/heads/" NEW_BRANCH_NAME, 0,
-		GIT_OID_HEX_ZERO,
+		GIT_OID_SHA1_HEXZERO,
 		git_oid_tostr_s(git_commit_id(target)),
 		g_email, git_str_cstr(&buf));
 
@@ -362,7 +362,7 @@ void test_refs_reflog_messages__creating_branches_default_messages(void)
 	cl_git_pass(git_branch_create_from_annotated(&branch2, g_repo, NEW_BRANCH_NAME, annotated, true));
 
 	cl_reflog_check_entry(g_repo, "refs/heads/" NEW_BRANCH_NAME, 0,
-		GIT_OID_HEX_ZERO,
+		GIT_OID_SHA1_HEXZERO,
 		git_oid_tostr_s(git_commit_id(target)),
 		g_email, "branch: Created from e90810b8df3");
 

tests/libgit2/refs/reflog/reflog.c

@@ -52,7 +52,7 @@ static void assert_appends(const git_signature *committer, const git_oid *oid)
 
 	/* The first one was the creation of the branch */
 	entry = git_reflog_entry_byindex(reflog, 2);
-	cl_assert(git_oid_streq(&entry->oid_old, GIT_OID_HEX_ZERO) == 0);
+	cl_assert(git_oid_streq(&entry->oid_old, GIT_OID_SHA1_HEXZERO) == 0);
 
 	entry = git_reflog_entry_byindex(reflog, 1);
 	assert_signature(committer, entry->committer);

tests/libgit2/status/worktree.c

@@ -744,7 +744,7 @@ void test_status_worktree__conflict_has_no_oid(void)
 	git_index_entry entry = {{0}};
 	git_status_list *statuslist;
 	const git_status_entry *status;
-	git_oid zero_id = {{0}};
+	git_oid zero_id = GIT_OID_SHA1_ZERO;
 
 	entry.mode = 0100644;
 	entry.path = "modified_file";