further shrink diff

Author: MichaelChirico

R/as.data.table.R

@@ -130,8 +130,7 @@ as.data.table.list = function(x,
   n = length(x)
   eachnrow = integer(n)          # vector of lengths of each column. may not be equal if silent repetition is required.
   eachncol = integer(n)
-  missing.check.names = missing(check.names) || is.null(check.names) # is.null for #3193
-  if (missing.check.names) check.names = FALSE
+  missing.check.names = missing(check.names)
   origListNames = if (missing(.named)) names(x) else NULL  # as.data.table called directly, not from inside data.table() which provides .named, #3854
   empty_atomic = FALSE
   for (i in seq_len(n)) {