print.data.table row id in scientific notation

[jangorecki]

The row names while printing, in data.table the row id sequence, is printed in scientific notation. I wonder if it was like that all the time? or maybe it is something which came with 3.2.0?
It is some way confusing as does not distinct the row numbers.

library(data.table)
set.seed(1)
DT <- data.table(a = 1:5, b = letters[1:3], d = rnorm(5*3*1e6))
DT
#          a b          d
#1.0e+00: 1 a -0.6264538
#2.0e+00: 2 b  0.1836433
#3.0e+00: 3 c -0.8356286
#4.0e+00: 4 a  1.5952808
#5.0e+00: 5 b  0.3295078
#      ---               
#1.5e+07: 1 b  0.8778030
#1.5e+07: 2 c -1.8297175
#1.5e+07: 3 a -2.0020279
#1.5e+07: 4 b -0.5252506
#1.5e+07: 5 c -1.5342523

R version 3.2.0 (2015-04-16)
Platform: x86_64-pc-linux-gnu (64-bit)
Running under: Ubuntu 14.04.2 LTS

locale:
 [1] LC_CTYPE=en_US.UTF-8       LC_NUMERIC=C               LC_TIME=en_DK.UTF-8        LC_COLLATE=en_US.UTF-8     LC_MONETARY=en_US.UTF-8    LC_MESSAGES=C              LC_PAPER=en_US.UTF-8       LC_NAME=C                  LC_ADDRESS=C              
[10] LC_TELEPHONE=C             LC_MEASUREMENT=en_US.UTF-8 LC_IDENTIFICATION=C       

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base     

other attached packages:
[1] data.table_1.9.5

loaded via a namespace (and not attached):
[1] tools_3.2.0  knitr_1.10.5 chron_2.3-45

Below Frank's comment is related to #1307

[franknarf1]

Yeah, the printing thing is a bug visible in print.data.table. The last line of

if (isTRUE(row.names)) 
        rownames(toprint) = paste(format(rn, right = TRUE), ":", 
            sep = "")
    else rownames(toprint) = rep.int("", nrow(x))

should refer to nrow(toprint) instead.

I don't know about the rownumbers-over-1e7 thing. That's the highest I've ever needed to go in practice. I guess the culprit is the format line, but can't figure out how. It shows up the same (with scientific notation) for R 3.0.1.