Merge branch 'bc/object-id'

Conversion from unsigned char [40] to struct object_id continues.

* bc/object-id:
  Documentation: update and rename api-sha1-array.txt
  Rename sha1_array to oid_array
  Convert sha1_array_for_each_unique and for_each_abbrev to object_id
  Convert sha1_array_lookup to take struct object_id
  Convert remaining callers of sha1_array_lookup to object_id
  Make sha1_array_append take a struct object_id *
  sha1-array: convert internal storage for struct sha1_array to object_id
  builtin/pull: convert to struct object_id
  submodule: convert check_for_new_submodule_commits to object_id
  sha1_name: convert disambiguate_hint_fn to take object_id
  sha1_name: convert struct disambiguate_state to object_id
  test-sha1-array: convert most code to struct object_id
  parse-options-cb: convert sha1_array_append caller to struct object_id
  fsck: convert init_skiplist to struct object_id
  builtin/receive-pack: convert portions to struct object_id
  builtin/pull: convert portions to struct object_id
  builtin/diff: convert to struct object_id
  Convert GIT_SHA1_RAWSZ used for allocation to GIT_MAX_RAWSZ
  Convert GIT_SHA1_HEXSZ used for allocation to GIT_MAX_HEXSZ
  Define new hash-size constants for allocating memory

14 files changed, 169 insertions, 169 deletions

diff --git a/builtin/blame.c b/builtin/blame.c
index f7aa95f4ba..07506a3e45 100644
--- a/builtin/blame.c
+++ b/builtin/blame.c
@@ -1890,7 +1890,7 @@ static void emit_porcelain(struct scoreboard *sb, struct blame_entry *ent,
 	int cnt;
 	const char *cp;
 	struct origin *suspect = ent->suspect;
-	char hex[GIT_SHA1_HEXSZ + 1];
+	char hex[GIT_MAX_HEXSZ + 1];
 
 	oid_to_hex_r(hex, &suspect->commit->object.oid);
 	printf("%s %d %d %d\n",
@@ -1928,7 +1928,7 @@ static void emit_other(struct scoreboard *sb, struct blame_entry *ent, int opt)
 	const char *cp;
 	struct origin *suspect = ent->suspect;
 	struct commit_info ci;
-	char hex[GIT_SHA1_HEXSZ + 1];
+	char hex[GIT_MAX_HEXSZ + 1];
 	int show_raw_time = !!(opt & OUTPUT_RAW_TIMESTAMP);
 
 	get_commit_info(suspect->commit, &ci, 1);
diff --git a/builtin/cat-file.c b/builtin/cat-file.c
index 8b85cb8cf0..1890d7a639 100644
--- a/builtin/cat-file.c
+++ b/builtin/cat-file.c
@@ -401,10 +401,10 @@ struct object_cb_data {
 	struct expand_data *expand;
 };
 
-static int batch_object_cb(const unsigned char sha1[20], void *vdata)
+static int batch_object_cb(const struct object_id *oid, void *vdata)
 {
 	struct object_cb_data *data = vdata;
-	hashcpy(data->expand->oid.hash, sha1);
+	oidcpy(&data->expand->oid, oid);
 	batch_object_write(NULL, data->opt, data->expand);
 	return 0;
 }
@@ -413,7 +413,7 @@ static int batch_loose_object(const struct object_id *oid,
 			      const char *path,
 			      void *data)
 {
-	sha1_array_append(data, oid->hash);
+	oid_array_append(data, oid);
 	return 0;
 }
 
@@ -422,7 +422,7 @@ static int batch_packed_object(const struct object_id *oid,
 			       uint32_t pos,
 			       void *data)
 {
-	sha1_array_append(data, oid->hash);
+	oid_array_append(data, oid);
 	return 0;
 }
 
@@ -462,7 +462,7 @@ static int batch_objects(struct batch_options *opt)
 		data.info.typep = &data.type;
 
 	if (opt->all_objects) {
-		struct sha1_array sa = SHA1_ARRAY_INIT;
+		struct oid_array sa = OID_ARRAY_INIT;
 		struct object_cb_data cb;
 
 		for_each_loose_object(batch_loose_object, &sa, 0);
@@ -470,9 +470,9 @@ static int batch_objects(struct batch_options *opt)
 
 		cb.opt = opt;
 		cb.expand = &data;
-		sha1_array_for_each_unique(&sa, batch_object_cb, &cb);
+		oid_array_for_each_unique(&sa, batch_object_cb, &cb);
 
-		sha1_array_clear(&sa);
+		oid_array_clear(&sa);
 		return 0;
 	}
 
diff --git a/builtin/diff.c b/builtin/diff.c
index 3d64b85337..d184aafab9 100644
--- a/builtin/diff.c
+++ b/builtin/diff.c
@@ -21,7 +21,7 @@
 #define DIFF_NO_INDEX_IMPLICIT 2
 
 struct blobinfo {
-	unsigned char sha1[20];
+	struct object_id oid;
 	const char *name;
 	unsigned mode;
 };
@@ -31,22 +31,22 @@ static const char builtin_diff_usage[] =
 
 static void stuff_change(struct diff_options *opt,
 			 unsigned old_mode, unsigned new_mode,
-			 const unsigned char *old_sha1,
-			 const unsigned char *new_sha1,
-			 int old_sha1_valid,
-			 int new_sha1_valid,
+			 const struct object_id *old_oid,
+			 const struct object_id *new_oid,
+			 int old_oid_valid,
+			 int new_oid_valid,
 			 const char *old_name,
 			 const char *new_name)
 {
 	struct diff_filespec *one, *two;
 
-	if (!is_null_sha1(old_sha1) && !is_null_sha1(new_sha1) &&
-	    !hashcmp(old_sha1, new_sha1) && (old_mode == new_mode))
+	if (!is_null_oid(old_oid) && !is_null_oid(new_oid) &&
+	    !oidcmp(old_oid, new_oid) && (old_mode == new_mode))
 		return;
 
 	if (DIFF_OPT_TST(opt, REVERSE_DIFF)) {
 		SWAP(old_mode, new_mode);
-		SWAP(old_sha1, new_sha1);
+		SWAP(old_oid, new_oid);
 		SWAP(old_name, new_name);
 	}
 
@@ -57,8 +57,8 @@ static void stuff_change(struct diff_options *opt,
 
 	one = alloc_filespec(old_name);
 	two = alloc_filespec(new_name);
-	fill_filespec(one, old_sha1, old_sha1_valid, old_mode);
-	fill_filespec(two, new_sha1, new_sha1_valid, new_mode);
+	fill_filespec(one, old_oid->hash, old_oid_valid, old_mode);
+	fill_filespec(two, new_oid->hash, new_oid_valid, new_mode);
 
 	diff_queue(&diff_queued_diff, one, two);
 }
@@ -89,7 +89,7 @@ static int builtin_diff_b_f(struct rev_info *revs,
 
 	stuff_change(&revs->diffopt,
 		     blob[0].mode, canon_mode(st.st_mode),
-		     blob[0].sha1, null_sha1,
+		     &blob[0].oid, &null_oid,
 		     1, 0,
 		     path, path);
 	diffcore_std(&revs->diffopt);
@@ -114,7 +114,7 @@ static int builtin_diff_blobs(struct rev_info *revs,
 
 	stuff_change(&revs->diffopt,
 		     blob[0].mode, blob[1].mode,
-		     blob[0].sha1, blob[1].sha1,
+		     &blob[0].oid, &blob[1].oid,
 		     1, 1,
 		     blob[0].name, blob[1].name);
 	diffcore_std(&revs->diffopt);
@@ -160,7 +160,7 @@ static int builtin_diff_tree(struct rev_info *revs,
 			     struct object_array_entry *ent0,
 			     struct object_array_entry *ent1)
 {
-	const unsigned char *(sha1[2]);
+	const struct object_id *(oid[2]);
 	int swap = 0;
 
 	if (argc > 1)
@@ -172,9 +172,9 @@ static int builtin_diff_tree(struct rev_info *revs,
 	 */
 	if (ent1->item->flags & UNINTERESTING)
 		swap = 1;
-	sha1[swap] = ent0->item->oid.hash;
-	sha1[1 - swap] = ent1->item->oid.hash;
-	diff_tree_sha1(sha1[0], sha1[1], "", &revs->diffopt);
+	oid[swap] = &ent0->item->oid;
+	oid[1 - swap] = &ent1->item->oid;
+	diff_tree_sha1(oid[0]->hash, oid[1]->hash, "", &revs->diffopt);
 	log_tree_diff_flush(revs);
 	return 0;
 }
@@ -184,7 +184,7 @@ static int builtin_diff_combined(struct rev_info *revs,
 				 struct object_array_entry *ent,
 				 int ents)
 {
-	struct sha1_array parents = SHA1_ARRAY_INIT;
+	struct oid_array parents = OID_ARRAY_INIT;
 	int i;
 
 	if (argc > 1)
@@ -193,10 +193,10 @@ static int builtin_diff_combined(struct rev_info *revs,
 	if (!revs->dense_combined_merges && !revs->combine_merges)
 		revs->dense_combined_merges = revs->combine_merges = 1;
 	for (i = 1; i < ents; i++)
-		sha1_array_append(&parents, ent[i].item->oid.hash);
+		oid_array_append(&parents, &ent[i].item->oid);
 	diff_tree_combined(ent[0].item->oid.hash, &parents,
 			   revs->dense_combined_merges, revs);
-	sha1_array_clear(&parents);
+	oid_array_clear(&parents);
 	return 0;
 }
 
@@ -408,7 +408,7 @@ int cmd_diff(int argc, const char **argv, const char *prefix)
 		} else if (obj->type == OBJ_BLOB) {
 			if (2 <= blobs)
 				die(_("more than two blobs given: '%s'"), name);
-			hashcpy(blob[blobs].sha1, obj->oid.hash);
+			hashcpy(blob[blobs].oid.hash, obj->oid.hash);
 			blob[blobs].name = name;
 			blob[blobs].mode = entry->mode;
 			blobs++;
diff --git a/builtin/fetch-pack.c b/builtin/fetch-pack.c
index 2a1c1c213f..366b9d13f9 100644
--- a/builtin/fetch-pack.c
+++ b/builtin/fetch-pack.c
@@ -50,7 +50,7 @@ int cmd_fetch_pack(int argc, const char **argv, const char *prefix)
 	char **pack_lockfile_ptr = NULL;
 	struct child_process *conn;
 	struct fetch_pack_args args;
-	struct sha1_array shallow = SHA1_ARRAY_INIT;
+	struct oid_array shallow = OID_ARRAY_INIT;
 	struct string_list deepen_not = STRING_LIST_INIT_DUP;
 
 	packet_trace_identity("fetch-pack");
diff --git a/builtin/fetch.c b/builtin/fetch.c
index 4ef7a08afc..5f2c2ab23e 100644
--- a/builtin/fetch.c
+++ b/builtin/fetch.c
@@ -661,7 +661,7 @@ static int update_local_ref(struct ref *ref,
 
 		if ((recurse_submodules != RECURSE_SUBMODULES_OFF) &&
 		    (recurse_submodules != RECURSE_SUBMODULES_ON))
-			check_for_new_submodule_commits(ref->new_oid.hash);
+			check_for_new_submodule_commits(&ref->new_oid);
 		r = s_update_ref(msg, ref, 0);
 		format_display(display, r ? '!' : '*', what,
 			       r ? _("unable to update local ref") : NULL,
@@ -677,7 +677,7 @@ static int update_local_ref(struct ref *ref,
 		strbuf_add_unique_abbrev(&quickref, ref->new_oid.hash, DEFAULT_ABBREV);
 		if ((recurse_submodules != RECURSE_SUBMODULES_OFF) &&
 		    (recurse_submodules != RECURSE_SUBMODULES_ON))
-			check_for_new_submodule_commits(ref->new_oid.hash);
+			check_for_new_submodule_commits(&ref->new_oid);
 		r = s_update_ref("fast-forward", ref, 1);
 		format_display(display, r ? '!' : ' ', quickref.buf,
 			       r ? _("unable to update local ref") : NULL,
@@ -692,7 +692,7 @@ static int update_local_ref(struct ref *ref,
 		strbuf_add_unique_abbrev(&quickref, ref->new_oid.hash, DEFAULT_ABBREV);
 		if ((recurse_submodules != RECURSE_SUBMODULES_OFF) &&
 		    (recurse_submodules != RECURSE_SUBMODULES_ON))
-			check_for_new_submodule_commits(ref->new_oid.hash);
+			check_for_new_submodule_commits(&ref->new_oid);
 		r = s_update_ref("forced-update", ref, 1);
 		format_display(display, r ? '!' : '+', quickref.buf,
 			       r ? _("unable to update local ref") : _("forced update"),
diff --git a/builtin/merge-index.c b/builtin/merge-index.c
index 2d1b6db6bd..c99443b095 100644
--- a/builtin/merge-index.c
+++ b/builtin/merge-index.c
@@ -9,7 +9,7 @@ static int merge_entry(int pos, const char *path)
 {
 	int found;
 	const char *arguments[] = { pgm, "", "", "", path, "", "", "", NULL };
-	char hexbuf[4][GIT_SHA1_HEXSZ + 1];
+	char hexbuf[4][GIT_MAX_HEXSZ + 1];
 	char ownbuf[4][60];
 
 	if (pos >= active_nr)
diff --git a/builtin/merge.c b/builtin/merge.c
index 95572b1810..703827f006 100644
--- a/builtin/merge.c
+++ b/builtin/merge.c
@@ -1255,7 +1255,7 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
 	if (verify_signatures) {
 		for (p = remoteheads; p; p = p->next) {
 			struct commit *commit = p->item;
-			char hex[GIT_SHA1_HEXSZ + 1];
+			char hex[GIT_MAX_HEXSZ + 1];
 			struct signature_check signature_check;
 			memset(&signature_check, 0, sizeof(signature_check));
 
diff --git a/builtin/pack-objects.c b/builtin/pack-objects.c
index 84af7c2324..0fe35d1b5a 100644
--- a/builtin/pack-objects.c
+++ b/builtin/pack-objects.c
@@ -2672,16 +2672,16 @@ static int has_sha1_pack_kept_or_nonlocal(const unsigned char *sha1)
  *
  * This is filled by get_object_list.
  */
-static struct sha1_array recent_objects;
+static struct oid_array recent_objects;
 
-static int loosened_object_can_be_discarded(const unsigned char *sha1,
+static int loosened_object_can_be_discarded(const struct object_id *oid,
 					    unsigned long mtime)
 {
 	if (!unpack_unreachable_expiration)
 		return 0;
 	if (mtime > unpack_unreachable_expiration)
 		return 0;
-	if (sha1_array_lookup(&recent_objects, sha1) >= 0)
+	if (oid_array_lookup(&recent_objects, oid) >= 0)
 		return 0;
 	return 1;
 }
@@ -2690,7 +2690,7 @@ static void loosen_unused_packed_objects(struct rev_info *revs)
 {
 	struct packed_git *p;
 	uint32_t i;
-	const unsigned char *sha1;
+	struct object_id oid;
 
 	for (p = packed_git; p; p = p->next) {
 		if (!p->pack_local || p->pack_keep)
@@ -2700,11 +2700,11 @@ static void loosen_unused_packed_objects(struct rev_info *revs)
 			die("cannot open pack index");
 
 		for (i = 0; i < p->num_objects; i++) {
-			sha1 = nth_packed_object_sha1(p, i);
-			if (!packlist_find(&to_pack, sha1, NULL) &&
-			    !has_sha1_pack_kept_or_nonlocal(sha1) &&
-			    !loosened_object_can_be_discarded(sha1, p->mtime))
-				if (force_object_loose(sha1, p->mtime))
+			nth_packed_object_oid(&oid, p, i);
+			if (!packlist_find(&to_pack, oid.hash, NULL) &&
+			    !has_sha1_pack_kept_or_nonlocal(oid.hash) &&
+			    !loosened_object_can_be_discarded(&oid, p->mtime))
+				if (force_object_loose(oid.hash, p->mtime))
 					die("unable to force loose object");
 		}
 	}
@@ -2743,12 +2743,12 @@ static void record_recent_object(struct object *obj,
 				 const char *name,
 				 void *data)
 {
-	sha1_array_append(&recent_objects, obj->oid.hash);
+	oid_array_append(&recent_objects, &obj->oid);
 }
 
 static void record_recent_commit(struct commit *commit, void *data)
 {
-	sha1_array_append(&recent_objects, commit->object.oid.hash);
+	oid_array_append(&recent_objects, &commit->object.oid);
 }
 
 static void get_object_list(int ac, const char **av)
@@ -2816,7 +2816,7 @@ static void get_object_list(int ac, const char **av)
 	if (unpack_unreachable)
 		loosen_unused_packed_objects(&revs);
 
-	sha1_array_clear(&recent_objects);
+	oid_array_clear(&recent_objects);
 }
 
 static int option_parse_index_version(const struct option *opt,
diff --git a/builtin/patch-id.c b/builtin/patch-id.c
index a84d0003a3..81552e02e4 100644
--- a/builtin/patch-id.c
+++ b/builtin/patch-id.c
@@ -55,7 +55,7 @@ static int scan_hunk_header(const char *p, int *p_before, int *p_after)
 
 static void flush_one_hunk(struct object_id *result, git_SHA_CTX *ctx)
 {
-	unsigned char hash[GIT_SHA1_RAWSZ];
+	unsigned char hash[GIT_MAX_RAWSZ];
 	unsigned short carry = 0;
 	int i;
 
diff --git a/builtin/pull.c b/builtin/pull.c
index 3ecb881b0b..d8aa26d8ab 100644
--- a/builtin/pull.c
+++ b/builtin/pull.c
@@ -330,21 +330,21 @@ static int git_pull_config(const char *var, const char *value, void *cb)
  * Appends merge candidates from FETCH_HEAD that are not marked not-for-merge
  * into merge_heads.
  */
-static void get_merge_heads(struct sha1_array *merge_heads)
+static void get_merge_heads(struct oid_array *merge_heads)
 {
 	const char *filename = git_path("FETCH_HEAD");
 	FILE *fp;
 	struct strbuf sb = STRBUF_INIT;
-	unsigned char sha1[GIT_SHA1_RAWSZ];
+	struct object_id oid;
 
 	if (!(fp = fopen(filename, "r")))
 		die_errno(_("could not open '%s' for reading"), filename);
 	while (strbuf_getline_lf(&sb, fp) != EOF) {
-		if (get_sha1_hex(sb.buf, sha1))
+		if (get_oid_hex(sb.buf, &oid))
 			continue;  /* invalid line: does not start with SHA1 */
 		if (starts_with(sb.buf + GIT_SHA1_HEXSZ, "\tnot-for-merge\t"))
 			continue;  /* ref is not-for-merge */
-		sha1_array_append(merge_heads, sha1);
+		oid_array_append(merge_heads, &oid);
 	}
 	fclose(fp);
 	strbuf_release(&sb);
@@ -514,8 +514,8 @@ static int run_fetch(const char *repo, const char **refspecs)
 /**
  * "Pulls into void" by branching off merge_head.
  */
-static int pull_into_void(const unsigned char *merge_head,
-		const unsigned char *curr_head)
+static int pull_into_void(const struct object_id *merge_head,
+		const struct object_id *curr_head)
 {
 	/*
 	 * Two-way merge: we treat the index as based on an empty tree,
@@ -523,10 +523,10 @@ static int pull_into_void(const unsigned char *merge_head,
 	 * index/worktree changes that the user already made on the unborn
 	 * branch.
 	 */
-	if (checkout_fast_forward(EMPTY_TREE_SHA1_BIN, merge_head, 0))
+	if (checkout_fast_forward(EMPTY_TREE_SHA1_BIN, merge_head->hash, 0))
 		return 1;
 
-	if (update_ref("initial pull", "HEAD", merge_head, curr_head, 0, UPDATE_REFS_DIE_ON_ERR))
+	if (update_ref("initial pull", "HEAD", merge_head->hash, curr_head->hash, 0, UPDATE_REFS_DIE_ON_ERR))
 		return 1;
 
 	return 0;
@@ -647,7 +647,7 @@ static const char *get_tracking_branch(const char *remote, const char *refspec)
  * current branch forked from its remote tracking branch. Returns 0 on success,
  * -1 on failure.
  */
-static int get_rebase_fork_point(unsigned char *fork_point, const char *repo,
+static int get_rebase_fork_point(struct object_id *fork_point, const char *repo,
 		const char *refspec)
 {
 	int ret;
@@ -678,7 +678,7 @@ static int get_rebase_fork_point(unsigned char *fork_point, const char *repo,
 	if (ret)
 		goto cleanup;
 
-	ret = get_sha1_hex(sb.buf, fork_point);
+	ret = get_oid_hex(sb.buf, fork_point);
 	if (ret)
 		goto cleanup;
 
@@ -691,24 +691,24 @@ cleanup:
  * Sets merge_base to the octopus merge base of curr_head, merge_head and
  * fork_point. Returns 0 if a merge base is found, 1 otherwise.
  */
-static int get_octopus_merge_base(unsigned char *merge_base,
-		const unsigned char *curr_head,
-		const unsigned char *merge_head,
-		const unsigned char *fork_point)
+static int get_octopus_merge_base(struct object_id *merge_base,
+		const struct object_id *curr_head,
+		const struct object_id *merge_head,
+		const struct object_id *fork_point)
 {
 	struct commit_list *revs = NULL, *result;
 
-	commit_list_insert(lookup_commit_reference(curr_head), &revs);
-	commit_list_insert(lookup_commit_reference(merge_head), &revs);
-	if (!is_null_sha1(fork_point))
-		commit_list_insert(lookup_commit_reference(fork_point), &revs);
+	commit_list_insert(lookup_commit_reference(curr_head->hash), &revs);
+	commit_list_insert(lookup_commit_reference(merge_head->hash), &revs);
+	if (!is_null_oid(fork_point))
+		commit_list_insert(lookup_commit_reference(fork_point->hash), &revs);
 
 	result = reduce_heads(get_octopus_merge_bases(revs));
 	free_commit_list(revs);
 	if (!result)
 		return 1;
 
-	hashcpy(merge_base, result->item->object.oid.hash);
+	oidcpy(merge_base, &result->item->object.oid);
 	return 0;
 }
 
@@ -717,16 +717,16 @@ static int get_octopus_merge_base(unsigned char *merge_base,
  * fork point calculated by get_rebase_fork_point(), runs git-rebase with the
  * appropriate arguments and returns its exit status.
  */
-static int run_rebase(const unsigned char *curr_head,
-		const unsigned char *merge_head,
-		const unsigned char *fork_point)
+static int run_rebase(const struct object_id *curr_head,
+		const struct object_id *merge_head,
+		const struct object_id *fork_point)
 {
 	int ret;
-	unsigned char oct_merge_base[GIT_SHA1_RAWSZ];
+	struct object_id oct_merge_base;
 	struct argv_array args = ARGV_ARRAY_INIT;
 
-	if (!get_octopus_merge_base(oct_merge_base, curr_head, merge_head, fork_point))
-		if (!is_null_sha1(fork_point) && !hashcmp(oct_merge_base, fork_point))
+	if (!get_octopus_merge_base(&oct_merge_base, curr_head, merge_head, fork_point))
+		if (!is_null_oid(fork_point) && !oidcmp(&oct_merge_base, fork_point))
 			fork_point = NULL;
 
 	argv_array_push(&args, "rebase");
@@ -754,12 +754,12 @@ static int run_rebase(const unsigned char *curr_head,
 		warning(_("ignoring --verify-signatures for rebase"));
 
 	argv_array_push(&args, "--onto");
-	argv_array_push(&args, sha1_to_hex(merge_head));
+	argv_array_push(&args, oid_to_hex(merge_head));
 
-	if (fork_point && !is_null_sha1(fork_point))
-		argv_array_push(&args, sha1_to_hex(fork_point));
+	if (fork_point && !is_null_oid(fork_point))
+		argv_array_push(&args, oid_to_hex(fork_point));
 	else
-		argv_array_push(&args, sha1_to_hex(merge_head));
+		argv_array_push(&args, oid_to_hex(merge_head));
 
 	ret = run_command_v_opt(args.argv, RUN_GIT_CMD);
 	argv_array_clear(&args);
@@ -769,9 +769,9 @@ static int run_rebase(const unsigned char *curr_head,
 int cmd_pull(int argc, const char **argv, const char *prefix)
 {
 	const char *repo, **refspecs;
-	struct sha1_array merge_heads = SHA1_ARRAY_INIT;
-	unsigned char orig_head[GIT_SHA1_RAWSZ], curr_head[GIT_SHA1_RAWSZ];
-	unsigned char rebase_fork_point[GIT_SHA1_RAWSZ];
+	struct oid_array merge_heads = OID_ARRAY_INIT;
+	struct object_id orig_head, curr_head;
+	struct object_id rebase_fork_point;
 
 	if (!getenv("GIT_REFLOG_ACTION"))
 		set_reflog_message(argc, argv);
@@ -794,8 +794,8 @@ int cmd_pull(int argc, const char **argv, const char *prefix)
 	if (file_exists(git_path("MERGE_HEAD")))
 		die_conclude_merge();
 
-	if (get_sha1("HEAD", orig_head))
-		hashclr(orig_head);
+	if (get_oid("HEAD", &orig_head))
+		oidclr(&orig_head);
 
 	if (!opt_rebase && opt_autostash != -1)
 		die(_("--[no-]autostash option is only valid with --rebase."));
@@ -805,15 +805,15 @@ int cmd_pull(int argc, const char **argv, const char *prefix)
 		if (opt_autostash != -1)
 			autostash = opt_autostash;
 
-		if (is_null_sha1(orig_head) && !is_cache_unborn())
+		if (is_null_oid(&orig_head) && !is_cache_unborn())
 			die(_("Updating an unborn branch with changes added to the index."));
 
 		if (!autostash)
 			require_clean_work_tree(N_("pull with rebase"),
 				_("please commit or stash them."), 1, 0);
 
-		if (get_rebase_fork_point(rebase_fork_point, repo, *refspecs))
-			hashclr(rebase_fork_point);
+		if (get_rebase_fork_point(&rebase_fork_point, repo, *refspecs))
+			oidclr(&rebase_fork_point);
 	}
 
 	if (run_fetch(repo, refspecs))
@@ -822,11 +822,11 @@ int cmd_pull(int argc, const char **argv, const char *prefix)
 	if (opt_dry_run)
 		return 0;
 
-	if (get_sha1("HEAD", curr_head))
-		hashclr(curr_head);
+	if (get_oid("HEAD", &curr_head))
+		oidclr(&curr_head);
 
-	if (!is_null_sha1(orig_head) && !is_null_sha1(curr_head) &&
-			hashcmp(orig_head, curr_head)) {
+	if (!is_null_oid(&orig_head) && !is_null_oid(&curr_head) &&
+			oidcmp(&orig_head, &curr_head)) {
 		/*
 		 * The fetch involved updating the current branch.
 		 *
@@ -837,15 +837,15 @@ int cmd_pull(int argc, const char **argv, const char *prefix)
 
 		warning(_("fetch updated the current branch head.\n"
 			"fast-forwarding your working tree from\n"
-			"commit %s."), sha1_to_hex(orig_head));
+			"commit %s."), oid_to_hex(&orig_head));
 
-		if (checkout_fast_forward(orig_head, curr_head, 0))
+		if (checkout_fast_forward(orig_head.hash, curr_head.hash, 0))
 			die(_("Cannot fast-forward your working tree.\n"
 				"After making sure that you saved anything precious from\n"
 				"$ git diff %s\n"
 				"output, run\n"
 				"$ git reset --hard\n"
-				"to recover."), sha1_to_hex(orig_head));
+				"to recover."), oid_to_hex(&orig_head));
 	}
 
 	get_merge_heads(&merge_heads);
@@ -853,10 +853,10 @@ int cmd_pull(int argc, const char **argv, const char *prefix)
 	if (!merge_heads.nr)
 		die_no_merge_candidates(repo, refspecs);
 
-	if (is_null_sha1(orig_head)) {
+	if (is_null_oid(&orig_head)) {
 		if (merge_heads.nr > 1)
 			die(_("Cannot merge multiple branches into empty head."));
-		return pull_into_void(*merge_heads.sha1, curr_head);
+		return pull_into_void(merge_heads.oid, &curr_head);
 	}
 	if (opt_rebase && merge_heads.nr > 1)
 		die(_("Cannot rebase onto multiple branches."));
@@ -865,15 +865,15 @@ int cmd_pull(int argc, const char **argv, const char *prefix)
 		struct commit_list *list = NULL;
 		struct commit *merge_head, *head;
 
-		head = lookup_commit_reference(orig_head);
+		head = lookup_commit_reference(orig_head.hash);
 		commit_list_insert(head, &list);
-		merge_head = lookup_commit_reference(merge_heads.sha1[0]);
+		merge_head = lookup_commit_reference(merge_heads.oid[0].hash);
 		if (is_descendant_of(merge_head, list)) {
 			/* we can fast-forward this without invoking rebase */
 			opt_ff = "--ff-only";
 			return run_merge();
 		}
-		return run_rebase(curr_head, *merge_heads.sha1, rebase_fork_point);
+		return run_rebase(&curr_head, merge_heads.oid, &rebase_fork_point);
 	} else {
 		return run_merge();
 	}
diff --git a/builtin/receive-pack.c b/builtin/receive-pack.c
index 7020278081..3cba3fd278 100644
--- a/builtin/receive-pack.c
+++ b/builtin/receive-pack.c
@@ -225,10 +225,10 @@ static int receive_pack_config(const char *var, const char *value, void *cb)
 	return git_default_config(var, value, cb);
 }
 
-static void show_ref(const char *path, const unsigned char *sha1)
+static void show_ref(const char *path, const struct object_id *oid)
 {
 	if (sent_capabilities) {
-		packet_write_fmt(1, "%s %s\n", sha1_to_hex(sha1), path);
+		packet_write_fmt(1, "%s %s\n", oid_to_hex(oid), path);
 	} else {
 		struct strbuf cap = STRBUF_INIT;
 
@@ -244,7 +244,7 @@ static void show_ref(const char *path, const unsigned char *sha1)
 			strbuf_addstr(&cap, " push-options");
 		strbuf_addf(&cap, " agent=%s", git_user_agent_sanitized());
 		packet_write_fmt(1, "%s %s%c%s\n",
-			     sha1_to_hex(sha1), path, 0, cap.buf);
+			     oid_to_hex(oid), path, 0, cap.buf);
 		strbuf_release(&cap);
 		sent_capabilities = 1;
 	}
@@ -271,7 +271,7 @@ static int show_ref_cb(const char *path_full, const struct object_id *oid,
 	} else {
 		oidset_insert(seen, oid);
 	}
-	show_ref(path, oid->hash);
+	show_ref(path, oid);
 	return 0;
 }
 
@@ -284,7 +284,7 @@ static void show_one_alternate_ref(const char *refname,
 	if (oidset_insert(seen, oid))
 		return;
 
-	show_ref(".have", oid->hash);
+	show_ref(".have", oid);
 }
 
 static void write_head_info(void)
@@ -295,7 +295,7 @@ static void write_head_info(void)
 	for_each_alternate_ref(show_one_alternate_ref, &seen);
 	oidset_clear(&seen);
 	if (!sent_capabilities)
-		show_ref("capabilities^{}", null_sha1);
+		show_ref("capabilities^{}", &null_oid);
 
 	advertise_shallow_grafts(1);
 
@@ -309,8 +309,8 @@ struct command {
 	unsigned int skip_update:1,
 		     did_not_exist:1;
 	int index;
-	unsigned char old_sha1[20];
-	unsigned char new_sha1[20];
+	struct object_id old_oid;
+	struct object_id new_oid;
 	char ref_name[FLEX_ARRAY]; /* more */
 };
 
@@ -723,7 +723,7 @@ static int feed_receive_hook(void *state_, const char **bufp, size_t *sizep)
 		return -1; /* EOF */
 	strbuf_reset(&state->buf);
 	strbuf_addf(&state->buf, "%s %s %s\n",
-		    sha1_to_hex(cmd->old_sha1), sha1_to_hex(cmd->new_sha1),
+		    oid_to_hex(&cmd->old_oid), oid_to_hex(&cmd->new_oid),
 		    cmd->ref_name);
 	state->cmd = cmd->next;
 	if (bufp) {
@@ -764,8 +764,8 @@ static int run_update_hook(struct command *cmd)
 		return 0;
 
 	argv[1] = cmd->ref_name;
-	argv[2] = sha1_to_hex(cmd->old_sha1);
-	argv[3] = sha1_to_hex(cmd->new_sha1);
+	argv[2] = oid_to_hex(&cmd->old_oid);
+	argv[3] = oid_to_hex(&cmd->new_oid);
 	argv[4] = NULL;
 
 	proc.no_stdin = 1;
@@ -831,7 +831,7 @@ static int command_singleton_iterator(void *cb_data, unsigned char sha1[20]);
 static int update_shallow_ref(struct command *cmd, struct shallow_info *si)
 {
 	static struct lock_file shallow_lock;
-	struct sha1_array extra = SHA1_ARRAY_INIT;
+	struct oid_array extra = OID_ARRAY_INIT;
 	struct check_connected_options opt = CHECK_CONNECTED_INIT;
 	uint32_t mask = 1 << (cmd->index % 32);
 	int i;
@@ -842,13 +842,13 @@ static int update_shallow_ref(struct command *cmd, struct shallow_info *si)
 		if (si->used_shallow[i] &&
 		    (si->used_shallow[i][cmd->index / 32] & mask) &&
 		    !delayed_reachability_test(si, i))
-			sha1_array_append(&extra, si->shallow->sha1[i]);
+			oid_array_append(&extra, &si->shallow->oid[i]);
 
 	opt.env = tmp_objdir_env(tmp_objdir);
 	setup_alternate_shallow(&shallow_lock, &opt.shallow_file, &extra);
 	if (check_connected(command_singleton_iterator, cmd, &opt)) {
 		rollback_lock_file(&shallow_lock);
-		sha1_array_clear(&extra);
+		oid_array_clear(&extra);
 		return -1;
 	}
 
@@ -859,10 +859,10 @@ static int update_shallow_ref(struct command *cmd, struct shallow_info *si)
 	 * not lose these new roots..
 	 */
 	for (i = 0; i < extra.nr; i++)
-		register_shallow(extra.sha1[i]);
+		register_shallow(extra.oid[i].hash);
 
 	si->shallow_ref[cmd->index] = 0;
-	sha1_array_clear(&extra);
+	oid_array_clear(&extra);
 	return 0;
 }
 
@@ -988,8 +988,8 @@ static const char *update(struct command *cmd, struct shallow_info *si)
 	const char *name = cmd->ref_name;
 	struct strbuf namespaced_name_buf = STRBUF_INIT;
 	const char *namespaced_name, *ret;
-	unsigned char *old_sha1 = cmd->old_sha1;
-	unsigned char *new_sha1 = cmd->new_sha1;
+	struct object_id *old_oid = &cmd->old_oid;
+	struct object_id *new_oid = &cmd->new_oid;
 
 	/* only refs/... are allowed */
 	if (!starts_with(name, "refs/") || check_refname_format(name + 5, 0)) {
@@ -1014,20 +1014,20 @@ static const char *update(struct command *cmd, struct shallow_info *si)
 				refuse_unconfigured_deny();
 			return "branch is currently checked out";
 		case DENY_UPDATE_INSTEAD:
-			ret = update_worktree(new_sha1);
+			ret = update_worktree(new_oid->hash);
 			if (ret)
 				return ret;
 			break;
 		}
 	}
 
-	if (!is_null_sha1(new_sha1) && !has_sha1_file(new_sha1)) {
+	if (!is_null_oid(new_oid) && !has_object_file(new_oid)) {
 		error("unpack should have generated %s, "
-		      "but I can't find it!", sha1_to_hex(new_sha1));
+		      "but I can't find it!", oid_to_hex(new_oid));
 		return "bad pack";
 	}
 
-	if (!is_null_sha1(old_sha1) && is_null_sha1(new_sha1)) {
+	if (!is_null_oid(old_oid) && is_null_oid(new_oid)) {
 		if (deny_deletes && starts_with(name, "refs/heads/")) {
 			rp_error("denying ref deletion for %s", name);
 			return "deletion prohibited";
@@ -1053,14 +1053,14 @@ static const char *update(struct command *cmd, struct shallow_info *si)
 		}
 	}
 
-	if (deny_non_fast_forwards && !is_null_sha1(new_sha1) &&
-	    !is_null_sha1(old_sha1) &&
+	if (deny_non_fast_forwards && !is_null_oid(new_oid) &&
+	    !is_null_oid(old_oid) &&
 	    starts_with(name, "refs/heads/")) {
 		struct object *old_object, *new_object;
 		struct commit *old_commit, *new_commit;
 
-		old_object = parse_object(old_sha1);
-		new_object = parse_object(new_sha1);
+		old_object = parse_object(old_oid->hash);
+		new_object = parse_object(new_oid->hash);
 
 		if (!old_object || !new_object ||
 		    old_object->type != OBJ_COMMIT ||
@@ -1081,10 +1081,10 @@ static const char *update(struct command *cmd, struct shallow_info *si)
 		return "hook declined";
 	}
 
-	if (is_null_sha1(new_sha1)) {
+	if (is_null_oid(new_oid)) {
 		struct strbuf err = STRBUF_INIT;
-		if (!parse_object(old_sha1)) {
-			old_sha1 = NULL;
+		if (!parse_object(old_oid->hash)) {
+			old_oid = NULL;
 			if (ref_exists(name)) {
 				rp_warning("Allowing deletion of corrupt ref.");
 			} else {
@@ -1094,7 +1094,7 @@ static const char *update(struct command *cmd, struct shallow_info *si)
 		}
 		if (ref_transaction_delete(transaction,
 					   namespaced_name,
-					   old_sha1,
+					   old_oid->hash,
 					   0, "push", &err)) {
 			rp_error("%s", err.buf);
 			strbuf_release(&err);
@@ -1111,7 +1111,7 @@ static const char *update(struct command *cmd, struct shallow_info *si)
 
 		if (ref_transaction_update(transaction,
 					   namespaced_name,
-					   new_sha1, old_sha1,
+					   new_oid->hash, old_oid->hash,
 					   0, "push",
 					   &err)) {
 			rp_error("%s", err.buf);
@@ -1162,7 +1162,7 @@ static void check_aliased_update(struct command *cmd, struct string_list *list)
 	const char *dst_name;
 	struct string_list_item *item;
 	struct command *dst_cmd;
-	unsigned char sha1[GIT_SHA1_RAWSZ];
+	unsigned char sha1[GIT_MAX_RAWSZ];
 	int flag;
 
 	strbuf_addf(&buf, "%s%s", get_git_namespace(), cmd->ref_name);
@@ -1187,8 +1187,8 @@ static void check_aliased_update(struct command *cmd, struct string_list *list)
 
 	dst_cmd = (struct command *) item->util;
 
-	if (!hashcmp(cmd->old_sha1, dst_cmd->old_sha1) &&
-	    !hashcmp(cmd->new_sha1, dst_cmd->new_sha1))
+	if (!oidcmp(&cmd->old_oid, &dst_cmd->old_oid) &&
+	    !oidcmp(&cmd->new_oid, &dst_cmd->new_oid))
 		return;
 
 	dst_cmd->skip_update = 1;
@@ -1196,11 +1196,11 @@ static void check_aliased_update(struct command *cmd, struct string_list *list)
 	rp_error("refusing inconsistent update between symref '%s' (%s..%s) and"
 		 " its target '%s' (%s..%s)",
 		 cmd->ref_name,
-		 find_unique_abbrev(cmd->old_sha1, DEFAULT_ABBREV),
-		 find_unique_abbrev(cmd->new_sha1, DEFAULT_ABBREV),
+		 find_unique_abbrev(cmd->old_oid.hash, DEFAULT_ABBREV),
+		 find_unique_abbrev(cmd->new_oid.hash, DEFAULT_ABBREV),
 		 dst_cmd->ref_name,
-		 find_unique_abbrev(dst_cmd->old_sha1, DEFAULT_ABBREV),
-		 find_unique_abbrev(dst_cmd->new_sha1, DEFAULT_ABBREV));
+		 find_unique_abbrev(dst_cmd->old_oid.hash, DEFAULT_ABBREV),
+		 find_unique_abbrev(dst_cmd->new_oid.hash, DEFAULT_ABBREV));
 
 	cmd->error_string = dst_cmd->error_string =
 		"inconsistent aliased update";
@@ -1231,10 +1231,10 @@ static int command_singleton_iterator(void *cb_data, unsigned char sha1[20])
 	struct command **cmd_list = cb_data;
 	struct command *cmd = *cmd_list;
 
-	if (!cmd || is_null_sha1(cmd->new_sha1))
+	if (!cmd || is_null_oid(&cmd->new_oid))
 		return -1; /* end of list */
 	*cmd_list = NULL; /* this returns only one */
-	hashcpy(sha1, cmd->new_sha1);
+	hashcpy(sha1, cmd->new_oid.hash);
 	return 0;
 }
 
@@ -1275,8 +1275,8 @@ static int iterate_receive_command_list(void *cb_data, unsigned char sha1[20])
 		if (shallow_update && data->si->shallow_ref[cmd->index])
 			/* to be checked in update_shallow_ref() */
 			continue;
-		if (!is_null_sha1(cmd->new_sha1) && !cmd->skip_update) {
-			hashcpy(sha1, cmd->new_sha1);
+		if (!is_null_oid(&cmd->new_oid) && !cmd->skip_update) {
+			hashcpy(sha1, cmd->new_oid.hash);
 			*cmd_list = cmd->next;
 			return 0;
 		}
@@ -1303,7 +1303,7 @@ static void reject_updates_to_hidden(struct command *commands)
 
 		if (!ref_is_hidden(cmd->ref_name, refname_full.buf))
 			continue;
-		if (is_null_sha1(cmd->new_sha1))
+		if (is_null_oid(&cmd->new_oid))
 			cmd->error_string = "deny deleting a hidden ref";
 		else
 			cmd->error_string = "deny updating a hidden ref";
@@ -1486,23 +1486,23 @@ static struct command **queue_command(struct command **tail,
 				      const char *line,
 				      int linelen)
 {
-	unsigned char old_sha1[20], new_sha1[20];
+	struct object_id old_oid, new_oid;
 	struct command *cmd;
 	const char *refname;
 	int reflen;
+	const char *p;
 
-	if (linelen < 83 ||
-	    line[40] != ' ' ||
-	    line[81] != ' ' ||
-	    get_sha1_hex(line, old_sha1) ||
-	    get_sha1_hex(line + 41, new_sha1))
+	if (parse_oid_hex(line, &old_oid, &p) ||
+	    *p++ != ' ' ||
+	    parse_oid_hex(p, &new_oid, &p) ||
+	    *p++ != ' ')
 		die("protocol error: expected old/new/ref, got '%s'", line);
 
-	refname = line + 82;
-	reflen = linelen - 82;
+	refname = p;
+	reflen = linelen - (p - line);
 	FLEX_ALLOC_MEM(cmd, ref_name, refname, reflen);
-	hashcpy(cmd->old_sha1, old_sha1);
-	hashcpy(cmd->new_sha1, new_sha1);
+	oidcpy(&cmd->old_oid, &old_oid);
+	oidcpy(&cmd->new_oid, &new_oid);
 	*tail = cmd;
 	return &cmd->next;
 }
@@ -1529,7 +1529,7 @@ static void queue_commands_from_cert(struct command **tail,
 	}
 }
 
-static struct command *read_head_info(struct sha1_array *shallow)
+static struct command *read_head_info(struct oid_array *shallow)
 {
 	struct command *commands = NULL;
 	struct command **p = &commands;
@@ -1541,12 +1541,12 @@ static struct command *read_head_info(struct sha1_array *shallow)
 		if (!line)
 			break;
 
-		if (len == 48 && starts_with(line, "shallow ")) {
-			unsigned char sha1[20];
-			if (get_sha1_hex(line + 8, sha1))
+		if (len > 8 && starts_with(line, "shallow ")) {
+			struct object_id oid;
+			if (get_oid_hex(line + 8, &oid))
 				die("protocol error: expected shallow sha, got '%s'",
 				    line + 8);
-			sha1_array_append(shallow, sha1);
+			oid_array_append(shallow, &oid);
 			continue;
 		}
 
@@ -1807,7 +1807,7 @@ static void prepare_shallow_update(struct command *commands,
 
 static void update_shallow_info(struct command *commands,
 				struct shallow_info *si,
-				struct sha1_array *ref)
+				struct oid_array *ref)
 {
 	struct command *cmd;
 	int *ref_status;
@@ -1818,9 +1818,9 @@ static void update_shallow_info(struct command *commands,
 	}
 
 	for (cmd = commands; cmd; cmd = cmd->next) {
-		if (is_null_sha1(cmd->new_sha1))
+		if (is_null_oid(&cmd->new_oid))
 			continue;
-		sha1_array_append(ref, cmd->new_sha1);
+		oid_array_append(ref, &cmd->new_oid);
 		cmd->index = ref->nr - 1;
 	}
 	si->ref = ref;
@@ -1833,7 +1833,7 @@ static void update_shallow_info(struct command *commands,
 	ALLOC_ARRAY(ref_status, ref->nr);
 	assign_shallow_commits_to_refs(si, NULL, ref_status);
 	for (cmd = commands; cmd; cmd = cmd->next) {
-		if (is_null_sha1(cmd->new_sha1))
+		if (is_null_oid(&cmd->new_oid))
 			continue;
 		if (ref_status[cmd->index]) {
 			cmd->error_string = "shallow update not allowed";
@@ -1871,7 +1871,7 @@ static int delete_only(struct command *commands)
 {
 	struct command *cmd;
 	for (cmd = commands; cmd; cmd = cmd->next) {
-		if (!is_null_sha1(cmd->new_sha1))
+		if (!is_null_oid(&cmd->new_oid))
 			return 0;
 	}
 	return 1;
@@ -1881,8 +1881,8 @@ int cmd_receive_pack(int argc, const char **argv, const char *prefix)
 {
 	int advertise_refs = 0;
 	struct command *commands;
-	struct sha1_array shallow = SHA1_ARRAY_INIT;
-	struct sha1_array ref = SHA1_ARRAY_INIT;
+	struct oid_array shallow = OID_ARRAY_INIT;
+	struct oid_array ref = OID_ARRAY_INIT;
 	struct shallow_info si;
 
 	struct option options[] = {
@@ -1974,8 +1974,8 @@ int cmd_receive_pack(int argc, const char **argv, const char *prefix)
 	}
 	if (use_sideband)
 		packet_flush(1);
-	sha1_array_clear(&shallow);
-	sha1_array_clear(&ref);
+	oid_array_clear(&shallow);
+	oid_array_clear(&ref);
 	free((void *)push_cert_nonce);
 	return 0;
 }
diff --git a/builtin/rev-list.c b/builtin/rev-list.c
index 0aa93d5891..bcf77f0b8a 100644
--- a/builtin/rev-list.c
+++ b/builtin/rev-list.c
@@ -212,7 +212,7 @@ static void print_var_int(const char *var, int val)
 static int show_bisect_vars(struct rev_list_info *info, int reaches, int all)
 {
 	int cnt, flags = info->flags;
-	char hex[GIT_SHA1_HEXSZ + 1] = "";
+	char hex[GIT_MAX_HEXSZ + 1] = "";
 	struct commit_list *tried;
 	struct rev_info *revs = info->revs;
 
diff --git a/builtin/rev-parse.c b/builtin/rev-parse.c
index f54d7b5028..0513330910 100644
--- a/builtin/rev-parse.c
+++ b/builtin/rev-parse.c
@@ -205,9 +205,9 @@ static int anti_reference(const char *refname, const struct object_id *oid, int
 	return 0;
 }
 
-static int show_abbrev(const unsigned char *sha1, void *cb_data)
+static int show_abbrev(const struct object_id *oid, void *cb_data)
 {
-	show_rev(NORMAL, sha1, NULL);
+	show_rev(NORMAL, oid->hash, NULL);
 	return 0;
 }
 
diff --git a/builtin/send-pack.c b/builtin/send-pack.c
index 832fd7ed0a..b8e2e74fe0 100644
--- a/builtin/send-pack.c
+++ b/builtin/send-pack.c
@@ -131,8 +131,8 @@ int cmd_send_pack(int argc, const char **argv, const char *prefix)
 	const char *dest = NULL;
 	int fd[2];
 	struct child_process *conn;
-	struct sha1_array extra_have = SHA1_ARRAY_INIT;
-	struct sha1_array shallow = SHA1_ARRAY_INIT;
+	struct oid_array extra_have = OID_ARRAY_INIT;
+	struct oid_array shallow = OID_ARRAY_INIT;
 	struct ref *remote_refs, *local_refs;
 	int ret;
 	int helper_status = 0;