rbindlist SET_STRING_ELT error when DT has ordered variables

[ChristK]

Please see following example:

    require(data.table)
    DT1 = data.table(A = factor(1:2), B = factor(6:10), C = 0)
    DT2 = data.table(D = ordered(1:5), A = factor(1:2), C = 0)
    DT3 = data.table(A = factor(1:2), C = 0)
    l = list(DT1, DT2, DT3)
    rbindlist(l, use.names = T, fill = T)

The above returns:

     #Error in rbindlist(l, use.names = T, fill = T) : 
     # attempt to set index 6/6 in SET_STRING_ELT

When colD in DT2 is a factor instead of ordered factor, rbindlist works as expected:

    DT2 = data.table(D = factor(1:5), A = factor(1:2), C = 0)
    l = list(DT1, DT2, DT3)
    rbindlist(l, use.names = T, fill = T)
     #  A  B C  D
     #1: 1  6 0 NA
     #2: 2  7 0 NA
     #3: 1  8 0 NA
     #4: 2  9 0 NA
     #5: 1 10 0 NA
     #6: 1 NA 0  1
     #7: 2 NA 0  2
     #8: 1 NA 0  3
     #9: 2 NA 0  4
    #10: 1 NA 0  5
    #11: 1 NA 0 NA
    #12: 2 NA 0 NA

Reproducible in R v3.1.1 x64, data.table v1.9.5, Windows 8.1 x64 and LinuxMint x64

[ChristK]

Thank you for the super-fast fix