Made reading sys.configs consistent with OTP specification.

src/rebar_file_utils.erl

@@ -72,11 +72,14 @@ consult_config(State, Filename) ->
         [T] -> T;
         [] -> []
     end,
-    SubConfigs = [consult_config(State, Entry ++ ".config") ||
-                  Entry <- Config, is_list(Entry)
-                 ],
-
-    [Config | lists:merge(SubConfigs)].
+    lists:flatmap(
+      fun (SubConfig) when is_list(SubConfig) ->
+        case consult_config(State, SubConfig) of
+          [] -> consult_config(State, SubConfig ++ ".config");
+          X -> X
+        end;
+          (Entry) -> [Entry]
+      end, Config).
 
 format_error({bad_term_file, AppFile, Reason}) ->
     io_lib:format("Error reading file ~s: ~s", [AppFile, file:format_error(Reason)]).

src/rebar_prv_common_test.erl

@@ -218,9 +218,9 @@ select_tests(_, _, _, {error, _} = Error) -> Error;
 select_tests(State, ProjectApps, CmdOpts, CfgOpts) ->
     %% set application env if sys_config argument is provided
     SysConfigs = sys_config_list(CmdOpts, CfgOpts),
-    Configs = lists:flatmap(fun(Filename) ->
-                                rebar_file_utils:consult_config(State, Filename)
-                            end, SysConfigs),
+    Configs = lists:map(fun(Filename) ->
+                            rebar_file_utils:consult_config(State, Filename)
+                        end, SysConfigs),
     code:add_pathsa(rebar_state:code_paths(State, all_deps)),
     [application:load(Application) || Config <- Configs, {Application, _} <- Config],
     rebar_utils:reread_config(Configs),

src/rebar_prv_shell.erl

@@ -331,8 +331,8 @@ reread_config(State) ->
     case find_config(State) of
         no_config ->
             ok;
-        ConfigList ->
-            _ = rebar_utils:reread_config(ConfigList),
+        Config ->
+            _ = rebar_utils:reread_config([Config]),
             ok
     end.