Another Verilator Internal Error for shift by undef value

Verilator 06744b6 creates the following error:
%Error: Internal Error: ../V3Number.cpp:521: toUInt with 4-state 32'bxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

module issue_049(a, y);
  input [3:0] a;
  output [3:0] y;
  assign y = a << 1 <<< 0/0;
endmodule

History:
2014-05-23 Reported as Issue #772
2014-05-24 Fixed in GIT commit f705f9b