builtin/help.c: add --guide option

diff --git a/match-trees.c b/match-trees.c
index 26f7ed143e0649b6377ea427b5c57ca7ddb663d3..2bb734d51cbe59e3eed7c82e7522c594d5efa579 100644 (file)
--- a/match-trees.c
+++ b/match-trees.c
@@ -47,6 +47,13 @@ static int score_matches(unsigned mode1, unsigned mode2, const char *path)
        return score;
 }
 
+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.
  */
@@ -71,54 +78,35 @@ static int score_trees(const unsigned char *hash1, const unsigned char *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);