List size for large data.tables

Fixes #6607

Author: vlulla

R/tables.R

@@ -5,7 +5,7 @@ type_size = function(DT) {
   # for speed and ram efficiency, a lower bound by not descending into character string lengths or list items
   # if a more accurate and higher estimate is needed then user can pass object.size or alternative to mb=
   # in case number of columns is very large (e.g. 1e6 columns) then we use a for() to avoid allocation of sapply()
-  ans = 0L
+  ans = 0
   lookup = c("raw"=1L, "integer"=4L, "double"=8L, "complex"=16L)
   for (i in seq_along(DT)) {
     col = DT[[i]]

inst/tests/other.Rraw

@@ -766,3 +766,10 @@ if (loaded[["nanotime"]]) {
   # respect dec=',' for nanotime, related to #6446, corresponding to tests 2281.*
   test(31, fwrite(data.table(as.nanotime(.POSIXct(0))), dec=',', sep=';'), output="1970-01-01T00:00:00,000000000Z")
 }
+
+# test for bug#6607
+local({
+  DT <- as.data.table(lapply(1:15,function(i) runif(20e6)))
+  res <- tables()
+  data.table:::test(32, res[NAME=='DT',.(NAME,NROW,NCOL,MB)], data.table(NAME="DT",NROW=20000000L,NCOL=15L,MB=2288))
+})