213     u_check_tree(curbuf->b_u_oldhead, NULL, NULL);  in u_check()
215     if (seen_b_u_newhead == 0 && curbuf->b_u_oldhead != NULL  in u_check()
536 					       && curbuf->b_u_oldhead != NULL)  in u_savecommon()
538 	    u_header_T	    *uhfree = curbuf->b_u_oldhead;  in u_savecommon()
575 	    if (curbuf->b_u_oldhead == old_curhead)  in u_savecommon()
576 		curbuf->b_u_oldhead = uhp;  in u_savecommon()
607 	if (curbuf->b_u_oldhead == NULL)  in u_savecommon()
608 	    curbuf->b_u_oldhead = uhp;  in u_savecommon()
1260     put_header_ptr(bi, buf->b_u_oldhead);  in serialize_header()
1745     uhp = buf->b_u_oldhead;  in u_write_undo()
2142     curbuf->b_u_oldhead = old_idx < 0 ? NULL : uhp_table[old_idx];  in u_read_undo()
2267 		curbuf->b_u_curhead = curbuf->b_u_oldhead;  in u_doit()
2613 		    if (curbuf->b_u_oldhead == uhp)  in undo_time()
2614 			curbuf->b_u_oldhead = last;  in undo_time()
3091     uhp = curbuf->b_u_oldhead;  in ex_undolist()
3204     u_unch_branch(buf->b_u_oldhead);  in u_unchanged()
3356 	buf->b_u_oldhead = uhp->uh_prev.ptr;  in u_freeheader()
3383     if (uhp == buf->b_u_oldhead)  in u_freebranch()
3385 	while (buf->b_u_oldhead != NULL)  in u_freebranch()
3386 	    u_freeheader(buf, buf->b_u_oldhead, uhpp);  in u_freebranch()
3458     buf->b_u_newhead = buf->b_u_oldhead = buf->b_u_curhead = NULL;  in u_clearall()
3551     while (buf->b_u_oldhead != NULL)  in u_blockfree()
3552 	u_freeheader(buf, buf->b_u_oldhead, NULL);  in u_blockfree()
3724 	    u_eval_tree(curbuf->b_u_oldhead, list);  in f_undotree()