+ static char this_header[16384];
+ int offset;
+
+ if (!verbose_header)
+ return commit;
+
+ offset = sprintf(this_header, "%s%s (from %s)\n", header_prefix, commit, parent);
+ offset += pretty_print_commit(commit_format, msg, len, this_header + offset, sizeof(this_header) - offset);
+ return this_header;
+}
+
+static int diff_tree_commit(const unsigned char *commit, const char *name)
+{
+ unsigned long size, offset;
+ char *buf = read_object_with_reference(commit, "commit", &size, NULL);
+
+ if (!buf)
+ return -1;
+
+ if (!name) {
+ static char commit_name[60];
+ strcpy(commit_name, sha1_to_hex(commit));
+ name = commit_name;
+ }
+
+ /* Root commit? */
+ if (show_root_diff && memcmp(buf + 46, "parent ", 7)) {
+ header = generate_header(name, "root", buf, size);
+ diff_root_tree(commit, "");
+ }
+
+ /* More than one parent? */
+ if (ignore_merges) {
+ if (!memcmp(buf + 46 + 48, "parent ", 7))
+ return 0;
+ }
+
+ offset = 46;
+ while (offset + 48 < size && !memcmp(buf + offset, "parent ", 7)) {
+ unsigned char parent[20];
+ if (get_sha1_hex(buf + offset + 7, parent))
+ return -1;
+ header = generate_header(name, sha1_to_hex(parent), buf, size);
+ diff_tree_sha1_top(parent, commit, "");
+ if (!header && verbose_header) {
+ header_prefix = "\ndiff-tree ";
+ /*
+ * Don't print multiple merge entries if we
+ * don't print the diffs.
+ */
+ }
+ offset += 48;
+ }
+ return 0;
+}
+
+static int diff_tree_stdin(char *line)
+{
+ int len = strlen(line);
+ unsigned char commit[20], parent[20];
+ static char this_header[1000];
+
+ if (!len || line[len-1] != '\n')
+ return -1;
+ line[len-1] = 0;
+ if (get_sha1_hex(line, commit))
+ return -1;
+ if (isspace(line[40]) && !get_sha1_hex(line+41, parent)) {
+ line[40] = 0;
+ line[81] = 0;
+ sprintf(this_header, "%s (from %s)\n", line, line+41);
+ header = this_header;
+ return diff_tree_sha1_top(parent, commit, "");
+ }
+ line[40] = 0;
+ return diff_tree_commit(commit, line);
+}
+
+static char *diff_tree_usage =
+"git-diff-tree [-p] [-r] [-z] [--stdin] [-m] [-s] [-v] [--pretty] [-t] [-R] [-B] [-M] [-C] [--find-copies-header] [-O<orderfile>] [-S<string>] [--pickaxe-all] <tree-ish> <tree-ish>";
+
+int main(int argc, const char **argv)
+{
+ int nr_sha1;
+ char line[1000];
+ unsigned char sha1[2][20];
+
+ nr_sha1 = 0;
+ for (;;) {
+ const char *arg;