Work around unexpected common_test behaviour

diameter_traffic_SUITE has four layers of nested groups, so when a
testcase is run it should get Config from four init_per_group plus one
init_per_testcase. This isn't what happens: Config is being accumulated
from several init_per_group in some manner that isn't clear, and the
skip in the parent commit somehow results in growing
test_server_gl:init/1 processes that eventually consume all memory.
Replacing rather than prepending to Config in init_per_group works
around this, but the common_test behaviour seems wrong.

1 files changed, 11 insertions, 2 deletions

diff --git a/lib/diameter/test/diameter_traffic_SUITE.erl b/lib/diameter/test/diameter_traffic_SUITE.erl
index fde7e9b8c2..a2c0f7fae6 100644
--- a/lib/diameter/test/diameter_traffic_SUITE.erl
+++ b/lib/diameter/test/diameter_traffic_SUITE.erl
@@ -325,7 +325,7 @@ init_per_group(Name, Config)
         false ->
             start_services(Config),
             add_transports(Config),
-            [{sleep, Name == parallel} | Config]
+            replace({sleep, Name == parallel}, Config)
     end;
 
 init_per_group(sctp = Name, Config) ->
@@ -352,7 +352,7 @@ init_per_group(Name, Config) ->
                        server_decoding = D,
                        server_sender = SS,
                        server_throttle = ST},
-            [{group, G}, {runlist, select()} | Config];
+            replace([{group, G}, {runlist, select()}], Config);
         _ ->
             Config
     end.
@@ -396,6 +396,15 @@ init_per_testcase(Name, Config) ->
 end_per_testcase(_, _) ->
     ok.
 
+%% replace/2
+
+replace(Pairs, Config)
+  when is_list(Pairs) ->
+    lists:foldl(fun replace/2, Config, Pairs);
+
+replace({Key, _} = T, Config) ->
+    [T | lists:keydelete(Key, 1, Config)].
+
 %% --------------------
 
 %% Testcases to run when services are started and connections