Closes #1402. Fixed issue with test 842.

README.md

@@ -61,6 +61,8 @@
 
   1. Updated error message on invalid joins to reflect the new `on=` syntax, [#1368](https://github.com/Rdatatable/data.table/issues/1368). Thanks @MichaelChirico.
 
+  2. Fixed test 842 to account for `gdata::last` as well, [#1402](https://github.com/Rdatatable/data.table/issues/1402). Thanks @JanGorecki. 
+
 ### Changes in v1.9.6  (on CRAN 19 Sep 2015)
 
 #### NEW FEATURES

inst/tests/tests.Rraw

@@ -2292,7 +2292,8 @@ if ("package:xts" %in% search()) {  # e.g. when run via R CMD check
 } else {
     cat("Test 841 not run. If required call library(xts) first.\n")
     # So these won't run from R CMD check (deliberately, for now) ...
-    test(842, last(list("a",1:2,89)), 89)  # xts's last returns a one item list here. Would prefer it to return the item itself.
+    ans = if ("package:gdata" %in% search()) list(89) else 89
+    test(842, last(list("a",1:2,89)), ans)  # xts's last and gdata::last returns a one item list here. Would prefer it to return the item itself.
     DT = data.table(a=1:3)
     test(842.1, last(DT), DT[3L])
     # xts's last returns a 3L atomic here for 1 column data.frame, strangely. We wish for the last row, consistently. I tried