+ int parents;
+ unsigned char tree_sha1[20];
+ unsigned char parent_sha1[20];
+
+ if (memcmp(data, "tree ", 5))
+ return -1;
+ if (get_sha1_hex(data + 5, tree_sha1) < 0)
+ return -1;
+ mark_needs_sha1(sha1, "tree", tree_sha1);
+ data += 5 + 40 + 1; /* "tree " + <hex sha1> + '\n' */
+ parents = 0;
+ while (!memcmp(data, "parent ", 7)) {
+ if (get_sha1_hex(data + 7, parent_sha1) < 0)
+ return -1;
+ mark_needs_sha1(sha1, "commit", parent_sha1);
+ data += 7 + 40 + 1; /* "parent " + <hex sha1> + '\n' */
+ parents++;
+ }
+ if (!parents)
+ printf("root: %s\n", sha1_to_hex(sha1));