Merge branch 'bjorn/cuddle-with-tests' into maint

* bjorn/cuddle-with-tests: (23 commits)
  rand_SUITE: Speed up basic_stats/1
  base64_SUITE: Speed up roundtrip/1
  lists_SUITE: Test lists:concat/2
  lists_SUITE: Test lists:split/2
  lists_SUITE: Add a test case for lists:prefix/2
  lists_SUITE: Add hof/1 to test all high-order functions
  lists_SUITE: Add test for lists:takewhile/1
  lists_SUITE: Run test cases in each group in parallel
  lists_SUITE: Test lists:keyreplace/4
  lists_SUITE: Extend flatten/1 test to also test flatlength/1
  lists_SUITE: Correct test of lists:flatten/2
  id_transform_SUITE: Modernize test suite
  io_proto_SUITE: Speed up determination of default shell
  io_proto_SUITE: Refactor up rtnode() and friends
  gen_event_SUITE: Remove unnecessary sleep calls
  proc_lib: Improve coverage for crash/1
  proc_lib_SUITE: Eliminate compiler warnings
  io_SUITE: Add coverage/1 to completely cover io_lib_pretty
  io_SUITE: Extend coverage of code for testing printable chars
  io_SUITE: Speed up test for bad +pc option
  ...

1 files changed, 26 insertions, 12 deletions

diff --git a/lib/stdlib/test/base64_SUITE.erl b/lib/stdlib/test/base64_SUITE.erl
index cca9b967d5..75eebba6c6 100644
--- a/lib/stdlib/test/base64_SUITE.erl
+++ b/lib/stdlib/test/base64_SUITE.erl
@@ -30,7 +30,8 @@
 %% Test cases must be exported.
 -export([base64_encode/1, base64_decode/1, base64_otp_5635/1,
 	 base64_otp_6279/1, big/1, illegal/1, mime_decode/1,
-	 mime_decode_to_string/1, roundtrip/1]).
+	 mime_decode_to_string/1,
+	 roundtrip_1/1, roundtrip_2/1, roundtrip_3/1, roundtrip_4/1]).
 
 init_per_testcase(_, Config) ->
     Dog = test_server:timetrap(?t:minutes(4)),
@@ -50,10 +51,11 @@ suite() -> [{ct_hooks,[ts_install_cth]}].
 all() -> 
     [base64_encode, base64_decode, base64_otp_5635,
      base64_otp_6279, big, illegal, mime_decode, mime_decode_to_string,
-     roundtrip].
+     {group, roundtrip}].
 
 groups() -> 
-    [].
+    [{roundtrip, [parallel],
+      [roundtrip_1, roundtrip_2, roundtrip_3, roundtrip_4]}].
 
 init_per_suite(Config) ->
     Config.
@@ -242,21 +244,33 @@ mime_decode_to_string(Config) when is_list(Config) ->
 
 %%-------------------------------------------------------------------------
 
-roundtrip(Config) when is_list(Config) ->
-    Sizes = lists:seq(1, 255) ++ lists:seq(2400-5, 2440),
-    roundtrip_1(Sizes, []).
+roundtrip_1(Config) when is_list(Config) ->
+    do_roundtrip(1).
 
-roundtrip_1([NextSize|Sizes], Current) ->
+roundtrip_2(Config) when is_list(Config) ->
+    do_roundtrip(2).
+
+roundtrip_3(Config) when is_list(Config) ->
+    do_roundtrip(3).
+
+roundtrip_4(Config) when is_list(Config) ->
+    do_roundtrip(4).
+
+do_roundtrip(Offset) ->
+    Sizes = lists:seq(Offset, 255, 4) ++ lists:seq(2400-6+Offset, 2440, 4),
+    do_roundtrip_1(Sizes, []).
+
+do_roundtrip_1([NextSize|Sizes], Current) ->
     Len = length(Current),
     io:format("~p", [Len]),
-    do_roundtrip(Current),
+    do_roundtrip_2(Current),
     Next = random_byte_list(NextSize - Len, Current),
-    roundtrip_1(Sizes, Next);
-roundtrip_1([], Last) ->
+    do_roundtrip_1(Sizes, Next);
+do_roundtrip_1([], Last) ->
     io:format("~p", [length(Last)]),
-    do_roundtrip(Last).
+    do_roundtrip_2(Last).
 
-do_roundtrip(List) ->
+do_roundtrip_2(List) ->
     Bin = list_to_binary(List),
     Base64Bin = base64:encode(List),
     Base64Bin = base64:encode(Bin),