181 	if (uhp->uh_alt_prev.ptr != exp_uh_alt_prev)  in u_check_tree()
185 				       exp_uh_alt_prev, uhp->uh_alt_prev.ptr);  in u_check_tree()
571 	    uhp->uh_alt_prev.ptr = old_curhead->uh_alt_prev.ptr;  in u_savecommon()
572 	    if (uhp->uh_alt_prev.ptr != NULL)  in u_savecommon()
573 		uhp->uh_alt_prev.ptr->uh_alt_next.ptr = uhp;  in u_savecommon()
574 	    old_curhead->uh_alt_prev.ptr = uhp;  in u_savecommon()
579 	    uhp->uh_alt_prev.ptr = NULL;  in u_savecommon()
1293     put_header_ptr(bi, uhp->uh_alt_prev.ptr);  in serialize_uhp()
1342     uhp->uh_alt_prev.seq = undo_read_4c(bi);  in unserialize_uhp()
1765 	else if (uhp->uh_next.ptr != NULL && uhp->uh_alt_prev.ptr == NULL  in u_write_undo()
1768 	else if (uhp->uh_alt_prev.ptr != NULL)  in u_write_undo()
1769 	    uhp = uhp->uh_alt_prev.ptr;  in u_write_undo()
2116 			      && uhp_table[j]->uh_seq == uhp->uh_alt_prev.seq)  in u_read_undo()
2118 		uhp->uh_alt_prev.ptr = uhp_table[j];  in u_read_undo()
2501 	    else if (uhp->uh_next.ptr != NULL && uhp->uh_alt_prev.ptr == NULL  in undo_time()
2515 		if (uhp->uh_alt_prev.ptr != NULL)  in undo_time()
2516 		    uhp = uhp->uh_alt_prev.ptr;  in undo_time()
2589 		while (uhp->uh_alt_prev.ptr != NULL  in undo_time()
2590 				     && uhp->uh_alt_prev.ptr->uh_walk == mark)  in undo_time()
2591 		    uhp = uhp->uh_alt_prev.ptr;  in undo_time()
2602 		    while (uhp->uh_alt_prev.ptr != NULL)  in undo_time()
2603 			uhp = uhp->uh_alt_prev.ptr;  in undo_time()
2605 			last->uh_alt_next.ptr->uh_alt_prev.ptr =  in undo_time()
2606 							last->uh_alt_prev.ptr;  in undo_time()
2607 		    last->uh_alt_prev.ptr->uh_alt_next.ptr =  in undo_time()
2609 		    last->uh_alt_prev.ptr = NULL;  in undo_time()
2611 		    uhp->uh_alt_prev.ptr = last;  in undo_time()
3131 	else if (uhp->uh_next.ptr != NULL && uhp->uh_alt_prev.ptr == NULL  in ex_undolist()
3143 	    if (uhp->uh_alt_prev.ptr != NULL)  in ex_undolist()
3144 		uhp = uhp->uh_alt_prev.ptr;  in ex_undolist()
3351     if (uhp->uh_alt_prev.ptr != NULL)  in u_freeheader()
3352 	uhp->uh_alt_prev.ptr->uh_alt_next.ptr = NULL;  in u_freeheader()
3390     if (uhp->uh_alt_prev.ptr != NULL)  in u_freebranch()
3391 	uhp->uh_alt_prev.ptr->uh_alt_next.ptr = NULL;  in u_freebranch()