Merge branch 'bc/object-id'

Move from unsigned char[20] to struct object_id continues.

* bc/object-id:
  match-trees: convert several leaf functions to use struct object_id
  tree-walk: convert tree_entry_extract() to use struct object_id
  struct name_entry: use struct object_id instead of unsigned char sha1[20]
  match-trees: convert shift_tree() and shift_tree_by() to use object_id
  test-match-trees: convert to use struct object_id
  sha1-name: introduce a get_oid() function

21 files changed, 109 insertions, 98 deletions

diff --git a/builtin/grep.c b/builtin/grep.c
index 111b6f6cf1..462e607901 100644
--- a/builtin/grep.c
+++ b/builtin/grep.c
@@ -438,7 +438,7 @@ static int grep_tree(struct grep_opt *opt, const struct pathspec *pathspec,
 		strbuf_add(base, entry.path, te_len);
 
 		if (S_ISREG(entry.mode)) {
-			hit |= grep_sha1(opt, entry.sha1, base->buf, tn_len,
+			hit |= grep_sha1(opt, entry.oid->hash, base->buf, tn_len,
 					 check_attr ? base->buf + tn_len : NULL);
 		}
 		else if (S_ISDIR(entry.mode)) {
@@ -447,10 +447,10 @@ static int grep_tree(struct grep_opt *opt, const struct pathspec *pathspec,
 			void *data;
 			unsigned long size;
 
-			data = lock_and_read_sha1_file(entry.sha1, &type, &size);
+			data = lock_and_read_sha1_file(entry.oid->hash, &type, &size);
 			if (!data)
 				die(_("unable to read tree (%s)"),
-				    sha1_to_hex(entry.sha1));
+				    oid_to_hex(entry.oid));
 
 			strbuf_addch(base, '/');
 			init_tree_desc(&sub, data, size);
diff --git a/builtin/merge-tree.c b/builtin/merge-tree.c
index ca570041df..5b7ab9b967 100644
--- a/builtin/merge-tree.c
+++ b/builtin/merge-tree.c
@@ -150,15 +150,15 @@ static void show_result(void)
 /* An empty entry never compares same, not even to another empty entry */
 static int same_entry(struct name_entry *a, struct name_entry *b)
 {
-	return	a->sha1 &&
-		b->sha1 &&
-		!hashcmp(a->sha1, b->sha1) &&
+	return	a->oid &&
+		b->oid &&
+		!oidcmp(a->oid, b->oid) &&
 		a->mode == b->mode;
 }
 
 static int both_empty(struct name_entry *a, struct name_entry *b)
 {
-	return !(a->sha1 || b->sha1);
+	return !(a->oid || b->oid);
 }
 
 static struct merge_list *create_entry(unsigned stage, unsigned mode, const unsigned char *sha1, const char *path)
@@ -188,8 +188,8 @@ static void resolve(const struct traverse_info *info, struct name_entry *ours, s
 		return;
 
 	path = traverse_path(info, result);
-	orig = create_entry(2, ours->mode, ours->sha1, path);
-	final = create_entry(0, result->mode, result->sha1, path);
+	orig = create_entry(2, ours->mode, ours->oid->hash, path);
+	final = create_entry(0, result->mode, result->oid->hash, path);
 
 	final->link = orig;
 
@@ -213,7 +213,7 @@ static void unresolved_directory(const struct traverse_info *info,
 
 	newbase = traverse_path(info, p);
 
-#define ENTRY_SHA1(e) (((e)->mode && S_ISDIR((e)->mode)) ? (e)->sha1 : NULL)
+#define ENTRY_SHA1(e) (((e)->mode && S_ISDIR((e)->mode)) ? (e)->oid->hash : NULL)
 	buf0 = fill_tree_descriptor(t+0, ENTRY_SHA1(n + 0));
 	buf1 = fill_tree_descriptor(t+1, ENTRY_SHA1(n + 1));
 	buf2 = fill_tree_descriptor(t+2, ENTRY_SHA1(n + 2));
@@ -239,7 +239,7 @@ static struct merge_list *link_entry(unsigned stage, const struct traverse_info
 		path = entry->path;
 	else
 		path = traverse_path(info, n);
-	link = create_entry(stage, n->mode, n->sha1, path);
+	link = create_entry(stage, n->mode, n->oid->hash, path);
 	link->link = entry;
 	return link;
 }
@@ -314,7 +314,7 @@ static int threeway_callback(int n, unsigned long mask, unsigned long dirmask, s
 	}
 
 	if (same_entry(entry+0, entry+1)) {
-		if (entry[2].sha1 && !S_ISDIR(entry[2].mode)) {
+		if (entry[2].oid && !S_ISDIR(entry[2].mode)) {
 			/* We did not touch, they modified -- take theirs */
 			resolve(info, entry+1, entry+2);
 			return mask;
diff --git a/builtin/pack-objects.c b/builtin/pack-objects.c
index a27de5b323..d56b2c2d1e 100644
--- a/builtin/pack-objects.c
+++ b/builtin/pack-objects.c
@@ -1186,7 +1186,7 @@ static void add_pbase_object(struct tree_desc *tree,
 		if (cmp < 0)
 			return;
 		if (name[cmplen] != '/') {
-			add_object_entry(entry.sha1,
+			add_object_entry(entry.oid->hash,
 					 object_type(entry.mode),
 					 fullname, 1);
 			return;
@@ -1197,7 +1197,7 @@ static void add_pbase_object(struct tree_desc *tree,
 			const char *down = name+cmplen+1;
 			int downlen = name_cmp_len(down);
 
-			tree = pbase_tree_get(entry.sha1);
+			tree = pbase_tree_get(entry.oid->hash);
 			if (!tree)
 				return;
 			init_tree_desc(&sub, tree->tree_data, tree->tree_size);
diff --git a/builtin/reflog.c b/builtin/reflog.c
index 2d46b6482a..7a7136e53e 100644
--- a/builtin/reflog.c
+++ b/builtin/reflog.c
@@ -84,8 +84,8 @@ static int tree_is_complete(const unsigned char *sha1)
 	init_tree_desc(&desc, tree->buffer, tree->size);
 	complete = 1;
 	while (tree_entry(&desc, &entry)) {
-		if (!has_sha1_file(entry.sha1) ||
-		    (S_ISDIR(entry.mode) && !tree_is_complete(entry.sha1))) {
+		if (!has_sha1_file(entry.oid->hash) ||
+		    (S_ISDIR(entry.mode) && !tree_is_complete(entry.oid->hash))) {
 			tree->object.flags |= INCOMPLETE;
 			complete = 0;
 		}
diff --git a/cache-tree.c b/cache-tree.c
index 3ebf9c3aa4..ddf0cc9f9a 100644
--- a/cache-tree.c
+++ b/cache-tree.c
@@ -663,7 +663,7 @@ static void prime_cache_tree_rec(struct cache_tree *it, struct tree *tree)
 			cnt++;
 		else {
 			struct cache_tree_sub *sub;
-			struct tree *subtree = lookup_tree(entry.sha1);
+			struct tree *subtree = lookup_tree(entry.oid->hash);
 			if (!subtree->object.parsed)
 				parse_tree(subtree);
 			sub = cache_tree_sub(it, entry.path);
@@ -710,7 +710,7 @@ int cache_tree_matches_traversal(struct cache_tree *root,
 
 	it = find_cache_tree_from_traversal(root, info);
 	it = cache_tree_find(it, ent->path);
-	if (it && it->entry_count > 0 && !hashcmp(ent->sha1, it->sha1))
+	if (it && it->entry_count > 0 && !hashcmp(ent->oid->hash, it->sha1))
 		return it->entry_count;
 	return 0;
 }
diff --git a/cache.h b/cache.h
index fd728f0793..160f8e32e3 100644
--- a/cache.h
+++ b/cache.h
@@ -1154,6 +1154,8 @@ extern int get_sha1_blob(const char *str, unsigned char *sha1);
 extern void maybe_die_on_misspelt_object_name(const char *name, const char *prefix);
 extern int get_sha1_with_context(const char *str, unsigned flags, unsigned char *sha1, struct object_context *orc);
 
+extern int get_oid(const char *str, struct object_id *oid);
+
 typedef int each_abbrev_fn(const unsigned char *sha1, void *);
 extern int for_each_abbrev(const char *prefix, each_abbrev_fn, void *);
 
@@ -1764,8 +1766,8 @@ int add_files_to_cache(const char *prefix, const struct pathspec *pathspec, int
 extern int diff_auto_refresh_index;
 
 /* match-trees.c */
-void shift_tree(const unsigned char *, const unsigned char *, unsigned char *, int);
-void shift_tree_by(const unsigned char *, const unsigned char *, unsigned char *, const char *);
+void shift_tree(const struct object_id *, const struct object_id *, struct object_id *, int);
+void shift_tree_by(const struct object_id *, const struct object_id *, struct object_id *, const char *);
 
 /*
  * whitespace rules.
diff --git a/fsck.c b/fsck.c
index ca4c685377..92b17f5d6a 100644
--- a/fsck.c
+++ b/fsck.c
@@ -312,9 +312,9 @@ static int fsck_walk_tree(struct tree *tree, void *data, struct fsck_options *op
 		if (S_ISGITLINK(entry.mode))
 			continue;
 		if (S_ISDIR(entry.mode))
-			result = options->walk(&lookup_tree(entry.sha1)->object, OBJ_TREE, data, options);
+			result = options->walk(&lookup_tree(entry.oid->hash)->object, OBJ_TREE, data, options);
 		else if (S_ISREG(entry.mode) || S_ISLNK(entry.mode))
-			result = options->walk(&lookup_blob(entry.sha1)->object, OBJ_BLOB, data, options);
+			result = options->walk(&lookup_blob(entry.oid->hash)->object, OBJ_BLOB, data, options);
 		else {
 			result = error("in tree %s: entry %s has bad mode %.6o",
 					oid_to_hex(&tree->object.oid), entry.path, entry.mode);
@@ -450,11 +450,11 @@ static int fsck_tree(struct tree *item, struct fsck_options *options)
 	while (desc.size) {
 		unsigned mode;
 		const char *name;
-		const unsigned char *sha1;
+		const struct object_id *oid;
 
-		sha1 = tree_entry_extract(&desc, &name, &mode);
+		oid = tree_entry_extract(&desc, &name, &mode);
 
-		has_null_sha1 |= is_null_sha1(sha1);
+		has_null_sha1 |= is_null_oid(oid);
 		has_full_path |= !!strchr(name, '/');
 		has_empty_name |= !*name;
 		has_dot |= !strcmp(name, ".");
diff --git a/http-push.c b/http-push.c
index ae2b7f19d2..a092f0288b 100644
--- a/http-push.c
+++ b/http-push.c
@@ -1312,10 +1312,10 @@ static struct object_list **process_tree(struct tree *tree,
 	while (tree_entry(&desc, &entry))
 		switch (object_type(entry.mode)) {
 		case OBJ_TREE:
-			p = process_tree(lookup_tree(entry.sha1), p);
+			p = process_tree(lookup_tree(entry.oid->hash), p);
 			break;
 		case OBJ_BLOB:
-			p = process_blob(lookup_blob(entry.sha1), p);
+			p = process_blob(lookup_blob(entry.oid->hash), p);
 			break;
 		default:
 			/* Subproject commit - not in this repository */
diff --git a/list-objects.c b/list-objects.c
index 917cc5d7c9..f3ca6aafb7 100644
--- a/list-objects.c
+++ b/list-objects.c
@@ -110,16 +110,16 @@ static void process_tree(struct rev_info *revs,
 
 		if (S_ISDIR(entry.mode))
 			process_tree(revs,
-				     lookup_tree(entry.sha1),
+				     lookup_tree(entry.oid->hash),
 				     show, base, entry.path,
 				     cb_data);
 		else if (S_ISGITLINK(entry.mode))
-			process_gitlink(revs, entry.sha1,
+			process_gitlink(revs, entry.oid->hash,
 					show, base, entry.path,
 					cb_data);
 		else
 			process_blob(revs,
-				     lookup_blob(entry.sha1),
+				     lookup_blob(entry.oid->hash),
 				     show, base, entry.path,
 				     cb_data);
 	}
diff --git a/match-trees.c b/match-trees.c
index 1ce0954a3e..396b7338df 100644
--- a/match-trees.c
+++ b/match-trees.c
@@ -48,17 +48,17 @@ static int score_matches(unsigned mode1, unsigned mode2, const char *path)
 }
 
 static void *fill_tree_desc_strict(struct tree_desc *desc,
-				   const unsigned char *hash)
+				   const struct object_id *hash)
 {
 	void *buffer;
 	enum object_type type;
 	unsigned long size;
 
-	buffer = read_sha1_file(hash, &type, &size);
+	buffer = read_sha1_file(hash->hash, &type, &size);
 	if (!buffer)
-		die("unable to read tree (%s)", sha1_to_hex(hash));
+		die("unable to read tree (%s)", oid_to_hex(hash));
 	if (type != OBJ_TREE)
-		die("%s is not a tree", sha1_to_hex(hash));
+		die("%s is not a tree", oid_to_hex(hash));
 	init_tree_desc(desc, buffer, size);
 	return buffer;
 }
@@ -73,7 +73,7 @@ static int base_name_entries_compare(const struct name_entry *a,
 /*
  * Inspect two trees, and give a score that tells how similar they are.
  */
-static int score_trees(const unsigned char *hash1, const unsigned char *hash2)
+static int score_trees(const struct object_id *hash1, const struct object_id *hash2)
 {
 	struct tree_desc one;
 	struct tree_desc two;
@@ -104,7 +104,7 @@ static int score_trees(const unsigned char *hash1, const unsigned char *hash2)
 		else if (cmp > 0)
 			/* path2 does not appear in one */
 			score += score_missing(e2.mode, e2.path);
-		else if (hashcmp(e1.sha1, e2.sha1))
+		else if (oidcmp(e1.oid, e2.oid))
 			/* they are different */
 			score += score_differs(e1.mode, e2.mode, e1.path);
 		else
@@ -119,8 +119,8 @@ static int score_trees(const unsigned char *hash1, const unsigned char *hash2)
 /*
  * Match one itself and its subtrees with two and pick the best match.
  */
-static void match_trees(const unsigned char *hash1,
-			const unsigned char *hash2,
+static void match_trees(const struct object_id *hash1,
+			const struct object_id *hash2,
 			int *best_score,
 			char **best_match,
 			const char *base,
@@ -131,7 +131,7 @@ static void match_trees(const unsigned char *hash1,
 
 	while (one.size) {
 		const char *path;
-		const unsigned char *elem;
+		const struct object_id *elem;
 		unsigned mode;
 		int score;
 
@@ -191,15 +191,15 @@ static int splice_tree(const unsigned char *hash1,
 	while (desc.size) {
 		const char *name;
 		unsigned mode;
-		const unsigned char *sha1;
+		const struct object_id *oid;
 
-		sha1 = tree_entry_extract(&desc, &name, &mode);
+		oid = tree_entry_extract(&desc, &name, &mode);
 		if (strlen(name) == toplen &&
 		    !memcmp(name, prefix, toplen)) {
 			if (!S_ISDIR(mode))
 				die("entry %s in tree %s is not a tree",
 				    name, sha1_to_hex(hash1));
-			rewrite_here = (unsigned char *) sha1;
+			rewrite_here = (unsigned char *) oid->hash;
 			break;
 		}
 		update_tree_entry(&desc);
@@ -229,9 +229,9 @@ static int splice_tree(const unsigned char *hash1,
  * other hand, it could cover tree one and we might need to pick a
  * subtree of it.
  */
-void shift_tree(const unsigned char *hash1,
-		const unsigned char *hash2,
-		unsigned char *shifted,
+void shift_tree(const struct object_id *hash1,
+		const struct object_id *hash2,
+		struct object_id *shifted,
 		int depth_limit)
 {
 	char *add_prefix;
@@ -262,7 +262,7 @@ void shift_tree(const unsigned char *hash1,
 	match_trees(hash2, hash1, &del_score, &del_prefix, "", depth_limit);
 
 	/* Assume we do not have to do any shifting */
-	hashcpy(shifted, hash2);
+	oidcpy(shifted, hash2);
 
 	if (add_score < del_score) {
 		/* We need to pick a subtree of two */
@@ -271,16 +271,16 @@ void shift_tree(const unsigned char *hash1,
 		if (!*del_prefix)
 			return;
 
-		if (get_tree_entry(hash2, del_prefix, shifted, &mode))
+		if (get_tree_entry(hash2->hash, del_prefix, shifted->hash, &mode))
 			die("cannot find path %s in tree %s",
-			    del_prefix, sha1_to_hex(hash2));
+			    del_prefix, oid_to_hex(hash2));
 		return;
 	}
 
 	if (!*add_prefix)
 		return;
 
-	splice_tree(hash1, add_prefix, hash2, shifted);
+	splice_tree(hash1->hash, add_prefix, hash2->hash, shifted->hash);
 }
 
 /*
@@ -288,22 +288,22 @@ void shift_tree(const unsigned char *hash1,
  * Unfortunately we cannot fundamentally tell which one to
  * be prefixed, as recursive merge can work in either direction.
  */
-void shift_tree_by(const unsigned char *hash1,
-		   const unsigned char *hash2,
-		   unsigned char *shifted,
+void shift_tree_by(const struct object_id *hash1,
+		   const struct object_id *hash2,
+		   struct object_id *shifted,
 		   const char *shift_prefix)
 {
-	unsigned char sub1[20], sub2[20];
+	struct object_id sub1, sub2;
 	unsigned mode1, mode2;
 	unsigned candidate = 0;
 
 	/* Can hash2 be a tree at shift_prefix in tree hash1? */
-	if (!get_tree_entry(hash1, shift_prefix, sub1, &mode1) &&
+	if (!get_tree_entry(hash1->hash, shift_prefix, sub1.hash, &mode1) &&
 	    S_ISDIR(mode1))
 		candidate |= 1;
 
 	/* Can hash1 be a tree at shift_prefix in tree hash2? */
-	if (!get_tree_entry(hash2, shift_prefix, sub2, &mode2) &&
+	if (!get_tree_entry(hash2->hash, shift_prefix, sub2.hash, &mode2) &&
 	    S_ISDIR(mode2))
 		candidate |= 2;
 
@@ -313,19 +313,19 @@ void shift_tree_by(const unsigned char *hash1,
 		int score;
 
 		candidate = 0;
-		score = score_trees(sub1, hash2);
+		score = score_trees(&sub1, hash2);
 		if (score > best_score) {
 			candidate = 1;
 			best_score = score;
 		}
-		score = score_trees(sub2, hash1);
+		score = score_trees(&sub2, hash1);
 		if (score > best_score)
 			candidate = 2;
 	}
 
 	if (!candidate) {
 		/* Neither is plausible -- do not shift */
-		hashcpy(shifted, hash2);
+		oidcpy(shifted, hash2);
 		return;
 	}
 
@@ -334,11 +334,11 @@ void shift_tree_by(const unsigned char *hash1,
 		 * shift tree2 down by adding shift_prefix above it
 		 * to match tree1.
 		 */
-		splice_tree(hash1, shift_prefix, hash2, shifted);
+		splice_tree(hash1->hash, shift_prefix, hash2->hash, shifted->hash);
 	else
 		/*
 		 * shift tree2 up by removing shift_prefix from it
 		 * to match tree1.
 		 */
-		hashcpy(shifted, sub2);
+		oidcpy(shifted, &sub2);
 }
diff --git a/merge-recursive.c b/merge-recursive.c
index 06d31ed873..65cb5d6c1f 100644
--- a/merge-recursive.c
+++ b/merge-recursive.c
@@ -29,9 +29,9 @@ static struct tree *shift_tree_object(struct tree *one, struct tree *two,
 	struct object_id shifted;
 
 	if (!*subtree_shift) {
-		shift_tree(one->object.oid.hash, two->object.oid.hash, shifted.hash, 0);
+		shift_tree(&one->object.oid, &two->object.oid, &shifted, 0);
 	} else {
-		shift_tree_by(one->object.oid.hash, two->object.oid.hash, shifted.hash,
+		shift_tree_by(&one->object.oid, &two->object.oid, &shifted,
 			      subtree_shift);
 	}
 	if (!oidcmp(&two->object.oid, &shifted))
diff --git a/notes.c b/notes.c
index 88cf4747c1..e4e4854d69 100644
--- a/notes.c
+++ b/notes.c
@@ -446,7 +446,7 @@ static void load_subtree(struct notes_tree *t, struct leaf_node *subtree,
 			l = (struct leaf_node *)
 				xcalloc(1, sizeof(struct leaf_node));
 			hashcpy(l->key_sha1, object_sha1);
-			hashcpy(l->val_sha1, entry.sha1);
+			hashcpy(l->val_sha1, entry.oid->hash);
 			if (len < 20) {
 				if (!S_ISDIR(entry.mode) || path_len != 2)
 					goto handle_non_note; /* not subtree */
@@ -493,7 +493,7 @@ handle_non_note:
 			}
 			strbuf_addstr(&non_note_path, entry.path);
 			add_non_note(t, strbuf_detach(&non_note_path, NULL),
-				     entry.mode, entry.sha1);
+				     entry.mode, entry.oid->hash);
 		}
 	}
 	free(buf);
diff --git a/revision.c b/revision.c
index b683476b9c..d30d1c4f80 100644
--- a/revision.c
+++ b/revision.c
@@ -59,10 +59,10 @@ static void mark_tree_contents_uninteresting(struct tree *tree)
 	while (tree_entry(&desc, &entry)) {
 		switch (object_type(entry.mode)) {
 		case OBJ_TREE:
-			mark_tree_uninteresting(lookup_tree(entry.sha1));
+			mark_tree_uninteresting(lookup_tree(entry.oid->hash));
 			break;
 		case OBJ_BLOB:
-			mark_blob_uninteresting(lookup_blob(entry.sha1));
+			mark_blob_uninteresting(lookup_blob(entry.oid->hash));
 			break;
 		default:
 			/* Subproject commit - not in this repository */
diff --git a/sha1_name.c b/sha1_name.c
index 776101e8d7..ca7ddd6f2c 100644
--- a/sha1_name.c
+++ b/sha1_name.c
@@ -1215,6 +1215,15 @@ int get_sha1(const char *name, unsigned char *sha1)
 }
 
 /*
+ * This is like "get_sha1()", but for struct object_id.
+ */
+int get_oid(const char *name, struct object_id *oid)
+{
+	return get_sha1(name, oid->hash);
+}
+
+
+/*
  * Many callers know that the user meant to name a commit-ish by
  * syntactical positions where the object name appears.  Calling this
  * function allows the machinery to disambiguate shorter-than-unique
diff --git a/t/helper/test-match-trees.c b/t/helper/test-match-trees.c
index 4dad7095f1..d446b8eaca 100644
--- a/t/helper/test-match-trees.c
+++ b/t/helper/test-match-trees.c
@@ -3,24 +3,24 @@
 
 int main(int ac, char **av)
 {
-	unsigned char hash1[20], hash2[20], shifted[20];
+	struct object_id hash1, hash2, shifted;
 	struct tree *one, *two;
 
 	setup_git_directory();
 
-	if (get_sha1(av[1], hash1))
+	if (get_oid(av[1], &hash1))
 		die("cannot parse %s as an object name", av[1]);
-	if (get_sha1(av[2], hash2))
+	if (get_oid(av[2], &hash2))
 		die("cannot parse %s as an object name", av[2]);
-	one = parse_tree_indirect(hash1);
+	one = parse_tree_indirect(hash1.hash);
 	if (!one)
 		die("not a tree-ish %s", av[1]);
-	two = parse_tree_indirect(hash2);
+	two = parse_tree_indirect(hash2.hash);
 	if (!two)
 		die("not a tree-ish %s", av[2]);
 
-	shift_tree(one->object.oid.hash, two->object.oid.hash, shifted, -1);
-	printf("shifted: %s\n", sha1_to_hex(shifted));
+	shift_tree(&one->object.oid, &two->object.oid, &shifted, -1);
+	printf("shifted: %s\n", oid_to_hex(&shifted));
 
 	exit(0);
 }
diff --git a/tree-diff.c b/tree-diff.c
index 4dda9a14ab..ff4e0d3cb6 100644
--- a/tree-diff.c
+++ b/tree-diff.c
@@ -183,7 +183,7 @@ static struct combine_diff_path *emit_path(struct combine_diff_path *p,
 
 	if (t) {
 		/* path present in resulting tree */
-		sha1 = tree_entry_extract(t, &path, &mode);
+		sha1 = tree_entry_extract(t, &path, &mode)->hash;
 		pathlen = tree_entry_len(&t->entry);
 		isdir = S_ISDIR(mode);
 	} else {
@@ -229,7 +229,7 @@ static struct combine_diff_path *emit_path(struct combine_diff_path *p,
 						DIFF_STATUS_ADDED;
 
 			if (tpi_valid) {
-				sha1_i = tp[i].entry.sha1;
+				sha1_i = tp[i].entry.oid->hash;
 				mode_i = tp[i].entry.mode;
 			}
 			else {
@@ -270,7 +270,7 @@ static struct combine_diff_path *emit_path(struct combine_diff_path *p,
 			/* same rule as in emitthis */
 			int tpi_valid = tp && !(tp[i].entry.mode & S_IFXMIN_NEQ);
 
-			parents_sha1[i] = tpi_valid ? tp[i].entry.sha1
+			parents_sha1[i] = tpi_valid ? tp[i].entry.oid->hash
 						    : NULL;
 		}
 
@@ -482,7 +482,7 @@ static struct combine_diff_path *ll_diff_tree_paths(
 						continue;
 
 					/* diff(t,pi) != ø */
-					if (hashcmp(t.entry.sha1, tp[i].entry.sha1) ||
+					if (oidcmp(t.entry.oid, tp[i].entry.oid) ||
 					    (t.entry.mode != tp[i].entry.mode))
 						continue;
 
diff --git a/tree-walk.c b/tree-walk.c
index cd4bb2c38b..ce27842439 100644
--- a/tree-walk.c
+++ b/tree-walk.c
@@ -38,7 +38,7 @@ static void decode_tree_entry(struct tree_desc *desc, const char *buf, unsigned
 	/* Initialize the descriptor entry */
 	desc->entry.path = path;
 	desc->entry.mode = canon_mode(mode);
-	desc->entry.sha1 = (const unsigned char *)(path + len);
+	desc->entry.oid  = (const struct object_id *)(path + len);
 }
 
 void init_tree_desc(struct tree_desc *desc, const void *buffer, unsigned long size)
@@ -76,7 +76,7 @@ static void entry_extract(struct tree_desc *t, struct name_entry *a)
 void update_tree_entry(struct tree_desc *desc)
 {
 	const void *buf = desc->buffer;
-	const unsigned char *end = desc->entry.sha1 + 20;
+	const unsigned char *end = desc->entry.oid->hash + 20;
 	unsigned long size = desc->size;
 	unsigned long len = end - (const unsigned char *)buf;
 
@@ -110,7 +110,7 @@ void setup_traverse_info(struct traverse_info *info, const char *base)
 		pathlen--;
 	info->pathlen = pathlen ? pathlen + 1 : 0;
 	info->name.path = base;
-	info->name.sha1 = (void *)(base + pathlen + 1);
+	info->name.oid = (void *)(base + pathlen + 1);
 	if (pathlen)
 		info->prev = &dummy;
 }
@@ -433,10 +433,10 @@ static int find_tree_entry(struct tree_desc *t, const char *name, unsigned char
 	int namelen = strlen(name);
 	while (t->size) {
 		const char *entry;
-		const unsigned char *sha1;
+		const struct object_id *oid;
 		int entrylen, cmp;
 
-		sha1 = tree_entry_extract(t, &entry, mode);
+		oid = tree_entry_extract(t, &entry, mode);
 		entrylen = tree_entry_len(&t->entry);
 		update_tree_entry(t);
 		if (entrylen > namelen)
@@ -447,7 +447,7 @@ static int find_tree_entry(struct tree_desc *t, const char *name, unsigned char
 		if (cmp < 0)
 			break;
 		if (entrylen == namelen) {
-			hashcpy(result, sha1);
+			hashcpy(result, oid->hash);
 			return 0;
 		}
 		if (name[entrylen] != '/')
@@ -455,10 +455,10 @@ static int find_tree_entry(struct tree_desc *t, const char *name, unsigned char
 		if (!S_ISDIR(*mode))
 			break;
 		if (++entrylen == namelen) {
-			hashcpy(result, sha1);
+			hashcpy(result, oid->hash);
 			return 0;
 		}
-		return get_tree_entry(sha1, name + entrylen, result, mode);
+		return get_tree_entry(oid->hash, name + entrylen, result, mode);
 	}
 	return -1;
 }
diff --git a/tree-walk.h b/tree-walk.h
index 174eb617df..97a7d6957e 100644
--- a/tree-walk.h
+++ b/tree-walk.h
@@ -2,7 +2,7 @@
 #define TREE_WALK_H
 
 struct name_entry {
-	const unsigned char *sha1;
+	const struct object_id *oid;
 	const char *path;
 	unsigned int mode;
 };
@@ -13,16 +13,16 @@ struct tree_desc {
 	unsigned int size;
 };
 
-static inline const unsigned char *tree_entry_extract(struct tree_desc *desc, const char **pathp, unsigned int *modep)
+static inline const struct object_id *tree_entry_extract(struct tree_desc *desc, const char **pathp, unsigned int *modep)
 {
 	*pathp = desc->entry.path;
 	*modep = desc->entry.mode;
-	return desc->entry.sha1;
+	return desc->entry.oid;
 }
 
 static inline int tree_entry_len(const struct name_entry *ne)
 {
-	return (const char *)ne->sha1 - ne->path - 1;
+	return (const char *)ne->oid - ne->path - 1;
 }
 
 void update_tree_entry(struct tree_desc *);
diff --git a/tree.c b/tree.c
index f79ff9813e..0089e52d9d 100644
--- a/tree.c
+++ b/tree.c
@@ -76,7 +76,7 @@ static int read_tree_1(struct tree *tree, struct strbuf *base,
 				continue;
 		}
 
-		switch (fn(entry.sha1, base,
+		switch (fn(entry.oid->hash, base,
 			   entry.path, entry.mode, stage, context)) {
 		case 0:
 			continue;
@@ -87,19 +87,19 @@ static int read_tree_1(struct tree *tree, struct strbuf *base,
 		}
 
 		if (S_ISDIR(entry.mode))
-			hashcpy(sha1, entry.sha1);
+			hashcpy(sha1, entry.oid->hash);
 		else if (S_ISGITLINK(entry.mode)) {
 			struct commit *commit;
 
-			commit = lookup_commit(entry.sha1);
+			commit = lookup_commit(entry.oid->hash);
 			if (!commit)
 				die("Commit %s in submodule path %s%s not found",
-				    sha1_to_hex(entry.sha1),
+				    oid_to_hex(entry.oid),
 				    base->buf, entry.path);
 
 			if (parse_commit(commit))
 				die("Invalid commit %s in submodule path %s%s",
-				    sha1_to_hex(entry.sha1),
+				    oid_to_hex(entry.oid),
 				    base->buf, entry.path);
 
 			hashcpy(sha1, commit->tree->object.oid.hash);
diff --git a/unpack-trees.c b/unpack-trees.c
index 9f55cc28b9..11308e9e5b 100644
--- a/unpack-trees.c
+++ b/unpack-trees.c
@@ -475,7 +475,7 @@ static int traverse_trees_recursive(int n, unsigned long dirmask,
 	for (i = 0; i < n; i++, dirmask >>= 1) {
 		const unsigned char *sha1 = NULL;
 		if (dirmask & 1)
-			sha1 = names[i].sha1;
+			sha1 = names[i].oid->hash;
 		buf[i] = fill_tree_descriptor(t+i, sha1);
 	}
 
@@ -591,7 +591,7 @@ static struct cache_entry *create_ce_entry(const struct traverse_info *info, con
 	ce->ce_mode = create_ce_mode(n->mode);
 	ce->ce_flags = create_ce_flags(stage);
 	ce->ce_namelen = len;
-	hashcpy(ce->sha1, n->sha1);
+	hashcpy(ce->sha1, n->oid->hash);
 	make_traverse_path(ce->name, info, n);
 
 	return ce;
diff --git a/walker.c b/walker.c
index 08773d419f..d95b007294 100644
--- a/walker.c
+++ b/walker.c
@@ -43,12 +43,12 @@ static int process_tree(struct walker *walker, struct tree *tree)
 		if (S_ISGITLINK(entry.mode))
 			continue;
 		if (S_ISDIR(entry.mode)) {
-			struct tree *tree = lookup_tree(entry.sha1);
+			struct tree *tree = lookup_tree(entry.oid->hash);
 			if (tree)
 				obj = &tree->object;
 		}
 		else {
-			struct blob *blob = lookup_blob(entry.sha1);
+			struct blob *blob = lookup_blob(entry.oid->hash);
 			if (blob)
 				obj = &blob->object;
 		}