rbind does not check if datetime classes are equal

[ecoRoland]

Example:

require(data.table)
DT1 <- data.table(date=as.POSIXct("2014-06-22", format="%Y-%m-%d", tz="GMT"))
DT2 <- data.table(date=as.Date("2014-06-23"))
rbind(DT1, DT2)
#'                               date
#'1: 2014-06-22 00:00:00
#'2: 1970-01-01 04:30:44
rbind(DT2, DT1)
#'                     date
#'1:       2014-06-23
#'2: 3844335-07-22
rbind.data.frame(DT2, DT1)
#'              date
#'1 2014-06-23
#'2 2014-06-22

[mattdowle]

Thanks. I reproduced in latest version and have assigned this to the v1.9.4 milestone.