+}
+
+void cgit_print_diff(const char *new_rev, const char *old_rev, const char *prefix)
+{
+ unsigned char sha1[20], sha2[20];
+ enum object_type type;
+ unsigned long size;
+ struct commit *commit, *commit2;
+
+ if (!new_rev)
+ new_rev = cgit_query_head;
+ get_sha1(new_rev, sha1);
+ type = sha1_object_info(sha1, &size);
+ if (type == OBJ_BAD) {
+ cgit_print_error(fmt("Bad object name: %s", new_rev));
+ return;
+ }
+ if (type != OBJ_COMMIT) {
+ cgit_print_error(fmt("Unhandled object type: %s",
+ typename(type)));
+ return;
+ }
+
+ commit = lookup_commit_reference(sha1);
+ if (!commit || parse_commit(commit))
+ cgit_print_error(fmt("Bad commit: %s", sha1_to_hex(sha1)));
+
+ if (old_rev)
+ get_sha1(old_rev, sha2);
+ else if (commit->parents && commit->parents->item)
+ hashcpy(sha2, commit->parents->item->object.sha1);
+ else
+ hashclr(sha2);
+
+ if (!is_null_sha1(sha2)) {
+ type = sha1_object_info(sha2, &size);
+ if (type == OBJ_BAD) {
+ cgit_print_error(fmt("Bad object name: %s", sha1_to_hex(sha2)));
+ return;
+ }
+ commit2 = lookup_commit_reference(sha2);
+ if (!commit2 || parse_commit(commit2))
+ cgit_print_error(fmt("Bad commit: %s", sha1_to_hex(sha2)));
+ }
+ html("<table class='diff'>");
+ html("<tr><td>");
+ cgit_diff_tree(sha2, sha1, filepair_cb, prefix);
+ html("</td></tr>");
+ html("</table>");