[Rd] segfault with POSIXlt zone=NULL zone=""

[frederik at ofb.net]

Hi all,

I ran into a segfault while playing with dates.

    $ R --no-init-file
    ...
    > library(lubridate); d=as.POSIXlt(floor_date(Sys.time(),"year")); d$zone=NULL; d$zone=""; d

    Attaching package: ‘lubridate’

    The following object is masked from ‘package:base’:

        date

    Warning message:
    package ‘lubridate’ was built under R version 3.4.0 

     *** caught segfault ***
    address (nil), cause 'unknown'

    Traceback:
     1: format.POSIXlt(x, usetz = TRUE)
     2: format(x, usetz = TRUE)
     3: print(format(x, usetz = TRUE), ...)
     4: print.POSIXlt(x)
     5: function (x, ...) UseMethod("print")(x)

    Possible actions:
    ...

Hope I'm not doing something illegal...

Thanks,

Frederick