fix: mutable dt alias from unique.data.table Rdatatable#5932

Thanks to @brookslogan for the original bug report.
dshemetov · Feb 24, 2024 · 1faa873 · 1faa873
1 parent 82f559f
commit 1faa873
Showing 1 changed file with 1 addition and 1 deletion.
diff --git a/R/duplicated.R b/R/duplicated.R
@@ -28,7 +28,7 @@ unique.data.table = function(x, incomparables=FALSE, fromLast=FALSE, by=seq_alon
   if (!isFALSE(incomparables)) {
     .NotYetUsed("incomparables != FALSE")
   }
-  if (nrow(x) <= 1L) return(x)
+  if (nrow(x) <= 1L) return(copy(x))
   if (!length(by)) by = NULL  #4594
   o = forderv(x, by=by, sort=FALSE, retGrp=TRUE)
   if (!is.null(cols)) {