Incorrect results with partially out-of-bounds part select

This should return y=4'b100x for a=1, but verilator returns y=0 instead (the MSB should be '1', obviously we don't care about the 'x' in the LSB that is the result of the (by one bit) out-of-bounds part select):

module issue_057(a, y);
  input [2:0] a;
  output [3:0] y;
  localparam [5:15] p = 51681708;
  assign y = p[15 + a -: 5];
endmodule

Self-contained test case: test020.v, test020_tb.v, test020.cc, test020.sh

This is with git e8edbad (verilator_3_864).

History:
2014-09-23 Reported as Issue #823
2017-07-01 Still broken in Verilator GIT 1da5a33 (3_906)