1 files changed, 53 insertions, 79 deletions

diff --git a/match-trees.c b/match-trees.c
index 26f7ed143e..1ce0954a3e 100644
--- a/match-trees.c
+++ b/match-trees.c
@@ -47,6 +47,29 @@ static int score_matches(unsigned mode1, unsigned mode2, const char *path)
 	return score;
 }
 
+static void *fill_tree_desc_strict(struct tree_desc *desc,
+				   const unsigned char *hash)
+{
+	void *buffer;
+	enum object_type type;
+	unsigned long size;
+
+	buffer = read_sha1_file(hash, &type, &size);
+	if (!buffer)
+		die("unable to read tree (%s)", sha1_to_hex(hash));
+	if (type != OBJ_TREE)
+		die("%s is not a tree", sha1_to_hex(hash));
+	init_tree_desc(desc, buffer, size);
+	return buffer;
+}
+
+static int base_name_entries_compare(const struct name_entry *a,
+				     const struct name_entry *b)
+{
+	return base_name_compare(a->path, tree_entry_len(a), a->mode,
+				 b->path, tree_entry_len(b), b->mode);
+}
+
 /*
  * Inspect two trees, and give a score that tells how similar they are.
  */
@@ -54,71 +77,39 @@ static int score_trees(const unsigned char *hash1, const unsigned char *hash2)
 {
 	struct tree_desc one;
 	struct tree_desc two;
-	void *one_buf, *two_buf;
+	void *one_buf = fill_tree_desc_strict(&one, hash1);
+	void *two_buf = fill_tree_desc_strict(&two, hash2);
 	int score = 0;
-	enum object_type type;
-	unsigned long size;
 
-	one_buf = read_sha1_file(hash1, &type, &size);
-	if (!one_buf)
-		die("unable to read tree (%s)", sha1_to_hex(hash1));
-	if (type != OBJ_TREE)
-		die("%s is not a tree", sha1_to_hex(hash1));
-	init_tree_desc(&one, one_buf, size);
-	two_buf = read_sha1_file(hash2, &type, &size);
-	if (!two_buf)
-		die("unable to read tree (%s)", sha1_to_hex(hash2));
-	if (type != OBJ_TREE)
-		die("%s is not a tree", sha1_to_hex(hash2));
-	init_tree_desc(&two, two_buf, size);
-	while (one.size | two.size) {
-		const unsigned char *elem1 = elem1;
-		const unsigned char *elem2 = elem2;
-		const char *path1 = path1;
-		const char *path2 = path2;
-		unsigned mode1 = mode1;
-		unsigned mode2 = mode2;
+	for (;;) {
+		struct name_entry e1, e2;
+		int got_entry_from_one = tree_entry(&one, &e1);
+		int got_entry_from_two = tree_entry(&two, &e2);
 		int cmp;
 
-		if (one.size)
-			elem1 = tree_entry_extract(&one, &path1, &mode1);
-		if (two.size)
-			elem2 = tree_entry_extract(&two, &path2, &mode2);
-
-		if (!one.size) {
-			/* two has more entries */
-			score += score_missing(mode2, path2);
-			update_tree_entry(&two);
-			continue;
-		}
-		if (!two.size) {
+		if (got_entry_from_one && got_entry_from_two)
+			cmp = base_name_entries_compare(&e1, &e2);
+		else if (got_entry_from_one)
 			/* two lacks this entry */
-			score += score_missing(mode1, path1);
-			update_tree_entry(&one);
-			continue;
-		}
-		cmp = base_name_compare(path1, strlen(path1), mode1,
-					path2, strlen(path2), mode2);
-		if (cmp < 0) {
+			cmp = -1;
+		else if (got_entry_from_two)
+			/* two has more entries */
+			cmp = 1;
+		else
+			break;
+
+		if (cmp < 0)
 			/* path1 does not appear in two */
-			score += score_missing(mode1, path1);
-			update_tree_entry(&one);
-			continue;
-		}
-		else if (cmp > 0) {
+			score += score_missing(e1.mode, e1.path);
+		else if (cmp > 0)
 			/* path2 does not appear in one */
-			score += score_missing(mode2, path2);
-			update_tree_entry(&two);
-			continue;
-		}
-		else if (hashcmp(elem1, elem2))
+			score += score_missing(e2.mode, e2.path);
+		else if (hashcmp(e1.sha1, e2.sha1))
 			/* they are different */
-			score += score_differs(mode1, mode2, path1);
+			score += score_differs(e1.mode, e2.mode, e1.path);
 		else
 			/* same subtree or blob */
-			score += score_matches(mode1, mode2, path1);
-		update_tree_entry(&one);
-		update_tree_entry(&two);
+			score += score_matches(e1.mode, e2.mode, e1.path);
 	}
 	free(one_buf);
 	free(two_buf);
@@ -136,16 +127,7 @@ static void match_trees(const unsigned char *hash1,
 			int recurse_limit)
 {
 	struct tree_desc one;
-	void *one_buf;
-	enum object_type type;
-	unsigned long size;
-
-	one_buf = read_sha1_file(hash1, &type, &size);
-	if (!one_buf)
-		die("unable to read tree (%s)", sha1_to_hex(hash1));
-	if (type != OBJ_TREE)
-		die("%s is not a tree", sha1_to_hex(hash1));
-	init_tree_desc(&one, one_buf, size);
+	void *one_buf = fill_tree_desc_strict(&one, hash1);
 
 	while (one.size) {
 		const char *path;
@@ -158,17 +140,12 @@ static void match_trees(const unsigned char *hash1,
 			goto next;
 		score = score_trees(elem, hash2);
 		if (*best_score < score) {
-			char *newpath;
-			newpath = xmalloc(strlen(base) + strlen(path) + 1);
-			sprintf(newpath, "%s%s", base, path);
 			free(*best_match);
-			*best_match = newpath;
+			*best_match = xstrfmt("%s%s", base, path);
 			*best_score = score;
 		}
 		if (recurse_limit) {
-			char *newbase;
-			newbase = xmalloc(strlen(base) + strlen(path) + 2);
-			sprintf(newbase, "%s%s/", base, path);
+			char *newbase = xstrfmt("%s%s/", base, path);
 			match_trees(elem, hash2, best_score, best_match,
 				    newbase, recurse_limit - 1);
 			free(newbase);
@@ -200,13 +177,10 @@ static int splice_tree(const unsigned char *hash1,
 	enum object_type type;
 	int status;
 
-	subpath = strchr(prefix, '/');
-	if (!subpath)
-		toplen = strlen(prefix);
-	else {
-		toplen = subpath - prefix;
+	subpath = strchrnul(prefix, '/');
+	toplen = subpath - prefix;
+	if (*subpath)
 		subpath++;
-	}
 
 	buf = read_sha1_file(hash1, &type, &sz);
 	if (!buf)
@@ -233,7 +207,7 @@ static int splice_tree(const unsigned char *hash1,
 	if (!rewrite_here)
 		die("entry %.*s not found in tree %s",
 		    toplen, prefix, sha1_to_hex(hash1));
-	if (subpath) {
+	if (*subpath) {
 		status = splice_tree(rewrite_here, subpath, hash2, subtree);
 		if (status)
 			return status;