Merge branch 'bw/object-id'

Conversion from uchar[20] to struct object_id continues.

* bw/object-id: (33 commits)
  diff: rename diff_fill_sha1_info to diff_fill_oid_info
  diffcore-rename: use is_empty_blob_oid
  tree-diff: convert path_appendnew to object_id
  tree-diff: convert diff_tree_paths to struct object_id
  tree-diff: convert try_to_follow_renames to struct object_id
  builtin/diff-tree: cleanup references to sha1
  diff-tree: convert diff_tree_sha1 to struct object_id
  notes-merge: convert write_note_to_worktree to struct object_id
  notes-merge: convert verify_notes_filepair to struct object_id
  notes-merge: convert find_notes_merge_pair_ps to struct object_id
  notes-merge: convert merge_from_diffs to struct object_id
  notes-merge: convert notes_merge* to struct object_id
  tree-diff: convert diff_root_tree_sha1 to struct object_id
  combine-diff: convert find_paths_* to struct object_id
  combine-diff: convert diff_tree_combined to struct object_id
  diff: convert diff_flush_patch_id to struct object_id
  patch-ids: convert to struct object_id
  diff: finish conversion for prepare_temp_file to struct object_id
  diff: convert reuse_worktree_file to struct object_id
  diff: convert fill_filespec to struct object_id
  ...

9 files changed, 100 insertions, 104 deletions

diff --git a/builtin/am.c b/builtin/am.c
index 8881d7361..3985f9a89 100644
--- a/builtin/am.c
+++ b/builtin/am.c
@@ -563,7 +563,7 @@ static int copy_notes_for_rebase(const struct am_state *state)
 			goto finish;
 		}
 
-		if (copy_note_for_rewrite(c, from_obj.hash, to_obj.hash))
+		if (copy_note_for_rewrite(c, &from_obj, &to_obj))
 			ret = error(_("Failed to copy notes from '%s' to '%s'"),
 					oid_to_hex(&from_obj), oid_to_hex(&to_obj));
 	}
diff --git a/builtin/commit.c b/builtin/commit.c
index ef52457ef..e3c9e190b 100644
--- a/builtin/commit.c
+++ b/builtin/commit.c
@@ -1806,7 +1806,7 @@ int cmd_commit(int argc, const char **argv, const char *prefix)
 		cfg = init_copy_notes_for_rewrite("amend");
 		if (cfg) {
 			/* we are amending, so current_head is not NULL */
-			copy_note_for_rewrite(cfg, current_head->object.oid.hash, oid.hash);
+			copy_note_for_rewrite(cfg, &current_head->object.oid, &oid);
 			finish_copy_notes_for_rewrite(cfg, "Notes added by 'git commit --amend'");
 		}
 		run_rewrite_hook(&current_head->object.oid, &oid);
diff --git a/builtin/diff-tree.c b/builtin/diff-tree.c
index 492245f42..1fd06eac4 100644
--- a/builtin/diff-tree.c
+++ b/builtin/diff-tree.c
@@ -7,7 +7,7 @@
 
 static struct rev_info log_tree_opt;
 
-static int diff_tree_commit_sha1(const struct object_id *oid)
+static int diff_tree_commit_oid(const struct object_id *oid)
 {
 	struct commit *commit = lookup_commit_reference(oid);
 	if (!commit)
@@ -49,8 +49,8 @@ static int stdin_diff_trees(struct tree *tree1, const char *p)
 		return -1;
 	printf("%s %s\n", oid_to_hex(&tree1->object.oid),
 			  oid_to_hex(&tree2->object.oid));
-	diff_tree_sha1(tree1->object.oid.hash, tree2->object.oid.hash,
-		       "", &log_tree_opt.diffopt);
+	diff_tree_oid(&tree1->object.oid, &tree2->object.oid,
+		      "", &log_tree_opt.diffopt);
 	log_tree_diff_flush(&log_tree_opt);
 	return 0;
 }
@@ -98,7 +98,6 @@ static void diff_tree_tweak_rev(struct rev_info *rev, struct setup_revision_opt
 
 int cmd_diff_tree(int argc, const char **argv, const char *prefix)
 {
-	int nr_sha1;
 	char line[1000];
 	struct object *tree1, *tree2;
 	static struct rev_info *opt = &log_tree_opt;
@@ -134,15 +133,14 @@ int cmd_diff_tree(int argc, const char **argv, const char *prefix)
 	 * second one is marked UNINTERESTING, we recover the original
 	 * order the user gave, i.e. "a..b", by swapping the trees.
 	 */
-	nr_sha1 = opt->pending.nr;
-	switch (nr_sha1) {
+	switch (opt->pending.nr) {
 	case 0:
 		if (!read_stdin)
 			usage(diff_tree_usage);
 		break;
 	case 1:
 		tree1 = opt->pending.objects[0].item;
-		diff_tree_commit_sha1(&tree1->oid);
+		diff_tree_commit_oid(&tree1->oid);
 		break;
 	case 2:
 		tree1 = opt->pending.objects[0].item;
@@ -150,9 +148,7 @@ int cmd_diff_tree(int argc, const char **argv, const char *prefix)
 		if (tree2->flags & UNINTERESTING) {
 			SWAP(tree2, tree1);
 		}
-		diff_tree_sha1(tree1->oid.hash,
-			       tree2->oid.hash,
-			       "", &opt->diffopt);
+		diff_tree_oid(&tree1->oid, &tree2->oid, "", &opt->diffopt);
 		log_tree_diff_flush(opt);
 		break;
 	}
diff --git a/builtin/diff.c b/builtin/diff.c
index 0c8f86e40..d9152c21b 100644
--- a/builtin/diff.c
+++ b/builtin/diff.c
@@ -56,8 +56,8 @@ static void stuff_change(struct diff_options *opt,
 
 	one = alloc_filespec(old_path);
 	two = alloc_filespec(new_path);
-	fill_filespec(one, old_oid->hash, old_oid_valid, old_mode);
-	fill_filespec(two, new_oid->hash, new_oid_valid, new_mode);
+	fill_filespec(one, old_oid, old_oid_valid, old_mode);
+	fill_filespec(two, new_oid, new_oid_valid, new_mode);
 
 	diff_queue(&diff_queued_diff, one, two);
 }
@@ -174,7 +174,7 @@ static int builtin_diff_tree(struct rev_info *revs,
 		swap = 1;
 	oid[swap] = &ent0->item->oid;
 	oid[1 - swap] = &ent1->item->oid;
-	diff_tree_sha1(oid[0]->hash, oid[1]->hash, "", &revs->diffopt);
+	diff_tree_oid(oid[0], oid[1], "", &revs->diffopt);
 	log_tree_diff_flush(revs);
 	return 0;
 }
@@ -194,7 +194,7 @@ static int builtin_diff_combined(struct rev_info *revs,
 		revs->dense_combined_merges = revs->combine_merges = 1;
 	for (i = 1; i < ents; i++)
 		oid_array_append(&parents, &ent[i].item->oid);
-	diff_tree_combined(ent[0].item->oid.hash, &parents,
+	diff_tree_combined(&ent[0].item->oid, &parents,
 			   revs->dense_combined_merges, revs);
 	oid_array_clear(&parents);
 	return 0;
diff --git a/builtin/fast-export.c b/builtin/fast-export.c
index 2dfed8745..a932be04f 100644
--- a/builtin/fast-export.c
+++ b/builtin/fast-export.c
@@ -562,12 +562,12 @@ static void handle_commit(struct commit *commit, struct rev_info *rev)
 	    get_object_mark(&commit->parents->item->object) != 0 &&
 	    !full_tree) {
 		parse_commit_or_die(commit->parents->item);
-		diff_tree_sha1(commit->parents->item->tree->object.oid.hash,
-			       commit->tree->object.oid.hash, "", &rev->diffopt);
+		diff_tree_oid(&commit->parents->item->tree->object.oid,
+			      &commit->tree->object.oid, "", &rev->diffopt);
 	}
 	else
-		diff_root_tree_sha1(commit->tree->object.oid.hash,
-				    "", &rev->diffopt);
+		diff_root_tree_oid(&commit->tree->object.oid,
+				   "", &rev->diffopt);
 
 	/* Export the referenced blobs, and remember the marks. */
 	for (i = 0; i < diff_queued_diff.nr; i++)
diff --git a/builtin/grep.c b/builtin/grep.c
index 26d43b4e4..3e4b9600e 100644
--- a/builtin/grep.c
+++ b/builtin/grep.c
@@ -342,7 +342,7 @@ static int grep_oid(struct grep_opt *opt, const struct object_id *oid,
 
 #ifndef NO_PTHREADS
 	if (num_threads) {
-		add_work(opt, GREP_SOURCE_SHA1, pathbuf.buf, path, oid);
+		add_work(opt, GREP_SOURCE_OID, pathbuf.buf, path, oid);
 		strbuf_release(&pathbuf);
 		return 0;
 	} else
@@ -351,7 +351,7 @@ static int grep_oid(struct grep_opt *opt, const struct object_id *oid,
 		struct grep_source gs;
 		int hit;
 
-		grep_source_init(&gs, GREP_SOURCE_SHA1, pathbuf.buf, path, oid);
+		grep_source_init(&gs, GREP_SOURCE_OID, pathbuf.buf, path, oid);
 		strbuf_release(&pathbuf);
 		hit = grep_source(opt, &gs);
 
@@ -587,7 +587,7 @@ static int grep_submodule_launch(struct grep_opt *opt,
 	 * with the object's name: 'tree-name:filename'.  In order to
 	 * provide uniformity of output we want to pass the name of the
 	 * parent project's object name to the submodule so the submodule can
-	 * prefix its output with the parent's name and not its own SHA1.
+	 * prefix its output with the parent's name and not its own OID.
 	 */
 	if (gs->identifier && end_of_base)
 		argv_array_pushf(&cp.args, "--parent-basename=%.*s",
@@ -600,12 +600,12 @@ static int grep_submodule_launch(struct grep_opt *opt,
 		 * If there is a tree identifier for the submodule, add the
 		 * rev after adding the submodule options but before the
 		 * pathspecs.  To do this we listen for the '--' and insert the
-		 * sha1 before pushing the '--' onto the child process argv
+		 * oid before pushing the '--' onto the child process argv
 		 * array.
 		 */
 		if (gs->identifier &&
 		    !strcmp("--", submodule_options.argv[i])) {
-			argv_array_push(&cp.args, sha1_to_hex(gs->identifier));
+			argv_array_push(&cp.args, oid_to_hex(gs->identifier));
 		}
 
 		argv_array_push(&cp.args, submodule_options.argv[i]);
@@ -635,11 +635,11 @@ static int grep_submodule_launch(struct grep_opt *opt,
 
 /*
  * Prep grep structures for a submodule grep
- * sha1: the sha1 of the submodule or NULL if using the working tree
+ * oid: the oid of the submodule or NULL if using the working tree
  * filename: name of the submodule including tree name of parent
  * path: location of the submodule
  */
-static int grep_submodule(struct grep_opt *opt, const unsigned char *sha1,
+static int grep_submodule(struct grep_opt *opt, const struct object_id *oid,
 			  const char *filename, const char *path)
 {
 	if (!is_submodule_initialized(path))
@@ -649,7 +649,7 @@ static int grep_submodule(struct grep_opt *opt, const unsigned char *sha1,
 		 * If searching history, check for the presense of the
 		 * submodule's gitdir before skipping the submodule.
 		 */
-		if (sha1) {
+		if (oid) {
 			const struct submodule *sub =
 					submodule_from_path(null_sha1, path);
 			if (sub)
@@ -664,7 +664,7 @@ static int grep_submodule(struct grep_opt *opt, const unsigned char *sha1,
 
 #ifndef NO_PTHREADS
 	if (num_threads) {
-		add_work(opt, GREP_SOURCE_SUBMODULE, filename, path, sha1);
+		add_work(opt, GREP_SOURCE_SUBMODULE, filename, path, oid);
 		return 0;
 	} else
 #endif
@@ -673,7 +673,7 @@ static int grep_submodule(struct grep_opt *opt, const unsigned char *sha1,
 		int hit;
 
 		grep_source_init(&gs, GREP_SOURCE_SUBMODULE,
-				 filename, path, sha1);
+				 filename, path, oid);
 		hit = grep_submodule_launch(opt, &gs);
 
 		grep_source_clear(&gs);
@@ -792,7 +792,7 @@ static int grep_tree(struct grep_opt *opt, const struct pathspec *pathspec,
 					 check_attr);
 			free(data);
 		} else if (recurse_submodules && S_ISGITLINK(entry.mode)) {
-			hit |= grep_submodule(opt, entry.oid->hash, base->buf,
+			hit |= grep_submodule(opt, entry.oid, base->buf,
 					      base->buf + tn_len);
 		}
 
diff --git a/builtin/log.c b/builtin/log.c
index a33c1a70a..998437b23 100644
--- a/builtin/log.c
+++ b/builtin/log.c
@@ -1052,9 +1052,9 @@ static void make_cover_letter(struct rev_info *rev, int use_stdout,
 
 	diff_setup_done(&opts);
 
-	diff_tree_sha1(origin->tree->object.oid.hash,
-		       head->tree->object.oid.hash,
-		       "", &opts);
+	diff_tree_oid(&origin->tree->object.oid,
+		      &head->tree->object.oid,
+		      "", &opts);
 	diffcore_std(&opts);
 	diff_flush(&opts);
 
@@ -1363,7 +1363,7 @@ static void prepare_bases(struct base_tree_info *bases,
 		struct object_id *patch_id;
 		if (commit->util)
 			continue;
-		if (commit_patch_id(commit, &diffopt, oid.hash, 0))
+		if (commit_patch_id(commit, &diffopt, &oid, 0))
 			die(_("cannot get patch id"));
 		ALLOC_GROW(bases->patch_id, bases->nr_patch_id + 1, bases->alloc_patch_id);
 		patch_id = bases->patch_id + bases->nr_patch_id;
diff --git a/builtin/merge.c b/builtin/merge.c
index eab03a026..84970cd85 100644
--- a/builtin/merge.c
+++ b/builtin/merge.c
@@ -415,7 +415,7 @@ static void finish(struct commit *head_commit,
 			DIFF_FORMAT_SUMMARY | DIFF_FORMAT_DIFFSTAT;
 		opts.detect_rename = DIFF_DETECT_RENAME;
 		diff_setup_done(&opts);
-		diff_tree_sha1(head->hash, new_head->hash, "", &opts);
+		diff_tree_oid(head, new_head, "", &opts);
 		diffcore_std(&opts);
 		diff_flush(&opts);
 	}
diff --git a/builtin/notes.c b/builtin/notes.c
index 7196bff0e..c939a84b7 100644
--- a/builtin/notes.c
+++ b/builtin/notes.c
@@ -109,11 +109,11 @@ static void free_note_data(struct note_data *d)
 	strbuf_release(&d->buf);
 }
 
-static int list_each_note(const unsigned char *object_sha1,
-		const unsigned char *note_sha1, char *note_path,
+static int list_each_note(const struct object_id *object_oid,
+		const struct object_id *note_oid, char *note_path,
 		void *cb_data)
 {
-	printf("%s %s\n", sha1_to_hex(note_sha1), sha1_to_hex(object_sha1));
+	printf("%s %s\n", oid_to_hex(note_oid), oid_to_hex(object_oid));
 	return 0;
 }
 
@@ -129,10 +129,10 @@ static void copy_obj_to_fd(int fd, const unsigned char *sha1)
 	}
 }
 
-static void write_commented_object(int fd, const unsigned char *object)
+static void write_commented_object(int fd, const struct object_id *object)
 {
 	const char *show_args[5] =
-		{"show", "--stat", "--no-notes", sha1_to_hex(object), NULL};
+		{"show", "--stat", "--no-notes", oid_to_hex(object), NULL};
 	struct child_process show = CHILD_PROCESS_INIT;
 	struct strbuf buf = STRBUF_INIT;
 	struct strbuf cbuf = STRBUF_INIT;
@@ -145,7 +145,7 @@ static void write_commented_object(int fd, const unsigned char *object)
 	show.git_cmd = 1;
 	if (start_command(&show))
 		die(_("unable to start 'show' for object '%s'"),
-		    sha1_to_hex(object));
+		    oid_to_hex(object));
 
 	if (strbuf_read(&buf, show.out, 0) < 0)
 		die_errno(_("could not read 'show' output"));
@@ -157,10 +157,10 @@ static void write_commented_object(int fd, const unsigned char *object)
 
 	if (finish_command(&show))
 		die(_("failed to finish 'show' for object '%s'"),
-		    sha1_to_hex(object));
+		    oid_to_hex(object));
 }
 
-static void prepare_note_data(const unsigned char *object, struct note_data *d,
+static void prepare_note_data(const struct object_id *object, struct note_data *d,
 		const unsigned char *old_note)
 {
 	if (d->use_editor || !d->given) {
@@ -243,16 +243,16 @@ static int parse_reuse_arg(const struct option *opt, const char *arg, int unset)
 {
 	struct note_data *d = opt->value;
 	char *buf;
-	unsigned char object[20];
+	struct object_id object;
 	enum object_type type;
 	unsigned long len;
 
 	if (d->buf.len)
 		strbuf_addch(&d->buf, '\n');
 
-	if (get_sha1(arg, object))
+	if (get_oid(arg, &object))
 		die(_("failed to resolve '%s' as a valid ref."), arg);
-	if (!(buf = read_sha1_file(object, &type, &len))) {
+	if (!(buf = read_sha1_file(object.hash, &type, &len))) {
 		free(buf);
 		die(_("failed to read object '%s'."), arg);
 	}
@@ -292,7 +292,7 @@ static int notes_copy_from_stdin(int force, const char *rewrite_cmd)
 	}
 
 	while (strbuf_getline_lf(&buf, stdin) != EOF) {
-		unsigned char from_obj[20], to_obj[20];
+		struct object_id from_obj, to_obj;
 		struct strbuf **split;
 		int err;
 
@@ -301,15 +301,15 @@ static int notes_copy_from_stdin(int force, const char *rewrite_cmd)
 			die(_("malformed input line: '%s'."), buf.buf);
 		strbuf_rtrim(split[0]);
 		strbuf_rtrim(split[1]);
-		if (get_sha1(split[0]->buf, from_obj))
+		if (get_oid(split[0]->buf, &from_obj))
 			die(_("failed to resolve '%s' as a valid ref."), split[0]->buf);
-		if (get_sha1(split[1]->buf, to_obj))
+		if (get_oid(split[1]->buf, &to_obj))
 			die(_("failed to resolve '%s' as a valid ref."), split[1]->buf);
 
 		if (rewrite_cmd)
-			err = copy_note_for_rewrite(c, from_obj, to_obj);
+			err = copy_note_for_rewrite(c, &from_obj, &to_obj);
 		else
-			err = copy_note(t, from_obj, to_obj, force,
+			err = copy_note(t, &from_obj, &to_obj, force,
 					combine_notes_overwrite);
 
 		if (err) {
@@ -352,8 +352,8 @@ static struct notes_tree *init_notes_check(const char *subcommand,
 static int list(int argc, const char **argv, const char *prefix)
 {
 	struct notes_tree *t;
-	unsigned char object[20];
-	const unsigned char *note;
+	struct object_id object;
+	const struct object_id *note;
 	int retval = -1;
 	struct option options[] = {
 		OPT_END()
@@ -370,15 +370,15 @@ static int list(int argc, const char **argv, const char *prefix)
 
 	t = init_notes_check("list", 0);
 	if (argc) {
-		if (get_sha1(argv[0], object))
+		if (get_oid(argv[0], &object))
 			die(_("failed to resolve '%s' as a valid ref."), argv[0]);
-		note = get_note(t, object);
+		note = get_note(t, &object);
 		if (note) {
-			puts(sha1_to_hex(note));
+			puts(oid_to_hex(note));
 			retval = 0;
 		} else
 			retval = error(_("no note found for object %s."),
-				       sha1_to_hex(object));
+				       oid_to_hex(&object));
 	} else
 		retval = for_each_note(t, 0, list_each_note, NULL);
 
@@ -393,8 +393,8 @@ static int add(int argc, const char **argv, const char *prefix)
 	int force = 0, allow_empty = 0;
 	const char *object_ref;
 	struct notes_tree *t;
-	unsigned char object[20], new_note[20];
-	const unsigned char *note;
+	struct object_id object, new_note;
+	const struct object_id *note;
 	struct note_data d = { 0, 0, NULL, STRBUF_INIT };
 	struct option options[] = {
 		{ OPTION_CALLBACK, 'm', "message", &d, N_("message"),
@@ -425,11 +425,11 @@ static int add(int argc, const char **argv, const char *prefix)
 
 	object_ref = argc > 1 ? argv[1] : "HEAD";
 
-	if (get_sha1(object_ref, object))
+	if (get_oid(object_ref, &object))
 		die(_("failed to resolve '%s' as a valid ref."), object_ref);
 
 	t = init_notes_check("add", NOTES_INIT_WRITABLE);
-	note = get_note(t, object);
+	note = get_note(t, &object);
 
 	if (note) {
 		if (!force) {
@@ -439,7 +439,7 @@ static int add(int argc, const char **argv, const char *prefix)
 				return error(_("Cannot add notes. "
 					"Found existing notes for object %s. "
 					"Use '-f' to overwrite existing notes"),
-					sha1_to_hex(object));
+					oid_to_hex(&object));
 			}
 			/*
 			 * Redirect to "edit" subcommand.
@@ -452,19 +452,19 @@ static int add(int argc, const char **argv, const char *prefix)
 			return append_edit(argc, argv, prefix);
 		}
 		fprintf(stderr, _("Overwriting existing notes for object %s\n"),
-			sha1_to_hex(object));
+			oid_to_hex(&object));
 	}
 
-	prepare_note_data(object, &d, note);
+	prepare_note_data(&object, &d, note->hash);
 	if (d.buf.len || allow_empty) {
-		write_note_data(&d, new_note);
-		if (add_note(t, object, new_note, combine_notes_overwrite))
+		write_note_data(&d, new_note.hash);
+		if (add_note(t, &object, &new_note, combine_notes_overwrite))
 			die("BUG: combine_notes_overwrite failed");
 		commit_notes(t, "Notes added by 'git notes add'");
 	} else {
 		fprintf(stderr, _("Removing note for object %s\n"),
-			sha1_to_hex(object));
-		remove_note(t, object);
+			oid_to_hex(&object));
+		remove_note(t, object.hash);
 		commit_notes(t, "Notes removed by 'git notes add'");
 	}
 
@@ -476,9 +476,9 @@ static int add(int argc, const char **argv, const char *prefix)
 static int copy(int argc, const char **argv, const char *prefix)
 {
 	int retval = 0, force = 0, from_stdin = 0;
-	const unsigned char *from_note, *note;
+	const struct object_id *from_note, *note;
 	const char *object_ref;
-	unsigned char object[20], from_obj[20];
+	struct object_id object, from_obj;
 	struct notes_tree *t;
 	const char *rewrite_cmd = NULL;
 	struct option options[] = {
@@ -511,37 +511,37 @@ static int copy(int argc, const char **argv, const char *prefix)
 		usage_with_options(git_notes_copy_usage, options);
 	}
 
-	if (get_sha1(argv[0], from_obj))
+	if (get_oid(argv[0], &from_obj))
 		die(_("failed to resolve '%s' as a valid ref."), argv[0]);
 
 	object_ref = 1 < argc ? argv[1] : "HEAD";
 
-	if (get_sha1(object_ref, object))
+	if (get_oid(object_ref, &object))
 		die(_("failed to resolve '%s' as a valid ref."), object_ref);
 
 	t = init_notes_check("copy", NOTES_INIT_WRITABLE);
-	note = get_note(t, object);
+	note = get_note(t, &object);
 
 	if (note) {
 		if (!force) {
 			retval = error(_("Cannot copy notes. Found existing "
 				       "notes for object %s. Use '-f' to "
 				       "overwrite existing notes"),
-				       sha1_to_hex(object));
+				       oid_to_hex(&object));
 			goto out;
 		}
 		fprintf(stderr, _("Overwriting existing notes for object %s\n"),
-			sha1_to_hex(object));
+			oid_to_hex(&object));
 	}
 
-	from_note = get_note(t, from_obj);
+	from_note = get_note(t, &from_obj);
 	if (!from_note) {
 		retval = error(_("missing notes on source object %s. Cannot "
-			       "copy."), sha1_to_hex(from_obj));
+			       "copy."), oid_to_hex(&from_obj));
 		goto out;
 	}
 
-	if (add_note(t, object, from_note, combine_notes_overwrite))
+	if (add_note(t, &object, from_note, combine_notes_overwrite))
 		die("BUG: combine_notes_overwrite failed");
 	commit_notes(t, "Notes added by 'git notes copy'");
 out:
@@ -554,8 +554,8 @@ static int append_edit(int argc, const char **argv, const char *prefix)
 	int allow_empty = 0;
 	const char *object_ref;
 	struct notes_tree *t;
-	unsigned char object[20], new_note[20];
-	const unsigned char *note;
+	struct object_id object, new_note;
+	const struct object_id *note;
 	char *logmsg;
 	const char * const *usage;
 	struct note_data d = { 0, 0, NULL, STRBUF_INIT };
@@ -594,19 +594,19 @@ static int append_edit(int argc, const char **argv, const char *prefix)
 
 	object_ref = 1 < argc ? argv[1] : "HEAD";
 
-	if (get_sha1(object_ref, object))
+	if (get_oid(object_ref, &object))
 		die(_("failed to resolve '%s' as a valid ref."), object_ref);
 
 	t = init_notes_check(argv[0], NOTES_INIT_WRITABLE);
-	note = get_note(t, object);
+	note = get_note(t, &object);
 
-	prepare_note_data(object, &d, edit ? note : NULL);
+	prepare_note_data(&object, &d, edit && note ? note->hash : NULL);
 
 	if (note && !edit) {
 		/* Append buf to previous note contents */
 		unsigned long size;
 		enum object_type type;
-		char *prev_buf = read_sha1_file(note, &type, &size);
+		char *prev_buf = read_sha1_file(note->hash, &type, &size);
 
 		strbuf_grow(&d.buf, size + 1);
 		if (d.buf.len && prev_buf && size)
@@ -617,14 +617,14 @@ static int append_edit(int argc, const char **argv, const char *prefix)
 	}
 
 	if (d.buf.len || allow_empty) {
-		write_note_data(&d, new_note);
-		if (add_note(t, object, new_note, combine_notes_overwrite))
+		write_note_data(&d, new_note.hash);
+		if (add_note(t, &object, &new_note, combine_notes_overwrite))
 			die("BUG: combine_notes_overwrite failed");
 		logmsg = xstrfmt("Notes added by 'git notes %s'", argv[0]);
 	} else {
 		fprintf(stderr, _("Removing note for object %s\n"),
-			sha1_to_hex(object));
-		remove_note(t, object);
+			oid_to_hex(&object));
+		remove_note(t, object.hash);
 		logmsg = xstrfmt("Notes removed by 'git notes %s'", argv[0]);
 	}
 	commit_notes(t, logmsg);
@@ -639,8 +639,8 @@ static int show(int argc, const char **argv, const char *prefix)
 {
 	const char *object_ref;
 	struct notes_tree *t;
-	unsigned char object[20];
-	const unsigned char *note;
+	struct object_id object;
+	const struct object_id *note;
 	int retval;
 	struct option options[] = {
 		OPT_END()
@@ -656,17 +656,17 @@ static int show(int argc, const char **argv, const char *prefix)
 
 	object_ref = argc ? argv[0] : "HEAD";
 
-	if (get_sha1(object_ref, object))
+	if (get_oid(object_ref, &object))
 		die(_("failed to resolve '%s' as a valid ref."), object_ref);
 
 	t = init_notes_check("show", 0);
-	note = get_note(t, object);
+	note = get_note(t, &object);
 
 	if (!note)
 		retval = error(_("no note found for object %s."),
-			       sha1_to_hex(object));
+			       oid_to_hex(&object));
 	else {
-		const char *show_args[3] = {"show", sha1_to_hex(note), NULL};
+		const char *show_args[3] = {"show", oid_to_hex(note), NULL};
 		retval = execv_git_cmd(show_args);
 	}
 	free_notes(t);
@@ -726,7 +726,7 @@ static int merge_commit(struct notes_merge_options *o)
 	if (!o->local_ref)
 		die(_("failed to resolve NOTES_MERGE_REF"));
 
-	if (notes_merge_commit(o, t, partial, oid.hash))
+	if (notes_merge_commit(o, t, partial, &oid))
 		die(_("failed to finalize notes merge"));
 
 	/* Reuse existing commit message in reflog message */
@@ -762,7 +762,7 @@ static int git_config_get_notes_strategy(const char *key,
 static int merge(int argc, const char **argv, const char *prefix)
 {
 	struct strbuf remote_ref = STRBUF_INIT, msg = STRBUF_INIT;
-	unsigned char result_sha1[20];
+	struct object_id result_oid;
 	struct notes_tree *t;
 	struct notes_merge_options o;
 	int do_merge = 0, do_commit = 0, do_abort = 0;
@@ -844,16 +844,16 @@ static int merge(int argc, const char **argv, const char *prefix)
 		    remote_ref.buf, default_notes_ref());
 	strbuf_add(&(o.commit_msg), msg.buf + 7, msg.len - 7); /* skip "notes: " */
 
-	result = notes_merge(&o, t, result_sha1);
+	result = notes_merge(&o, t, &result_oid);
 
-	if (result >= 0) /* Merge resulted (trivially) in result_sha1 */
+	if (result >= 0) /* Merge resulted (trivially) in result_oid */
 		/* Update default notes ref with new commit */
-		update_ref(msg.buf, default_notes_ref(), result_sha1, NULL,
+		update_ref(msg.buf, default_notes_ref(), result_oid.hash, NULL,
 			   0, UPDATE_REFS_DIE_ON_ERR);
 	else { /* Merge has unresolved conflicts */
 		const struct worktree *wt;
 		/* Update .git/NOTES_MERGE_PARTIAL with partial merge result */
-		update_ref(msg.buf, "NOTES_MERGE_PARTIAL", result_sha1, NULL,
+		update_ref(msg.buf, "NOTES_MERGE_PARTIAL", result_oid.hash, NULL,
 			   0, UPDATE_REFS_DIE_ON_ERR);
 		/* Store ref-to-be-updated into .git/NOTES_MERGE_REF */
 		wt = find_shared_symref("NOTES_MERGE_REF", default_notes_ref());
@@ -880,10 +880,10 @@ static int merge(int argc, const char **argv, const char *prefix)
 static int remove_one_note(struct notes_tree *t, const char *name, unsigned flag)
 {
 	int status;
-	unsigned char sha1[20];
-	if (get_sha1(name, sha1))
+	struct object_id oid;
+	if (get_oid(name, &oid))
 		return error(_("Failed to resolve '%s' as a valid ref."), name);
-	status = remove_note(t, sha1);
+	status = remove_note(t, oid.hash);
 	if (status)
 		fprintf(stderr, _("Object %s has no note\n"), name);
 	else