Do not apply overrides to a root application.

Overrides should apply to a layer below where they are declared. This
patch makes it so if the project root is an application (i.e. it isn't
'root' and therefore not an umbrella project), we omit applying
overrides in rebar_app_discover.

This in turn required changing a bunch of tests, because all the tests
worked with the idea that all overrides applied to all apps to validate
that they get inherited properly. The changes re-structure the cases so
they are written with an umbrella app, demonstrating that the changes
stick.

1 files changed, 9 insertions, 4 deletions

diff --git a/src/rebar_app_discover.erl b/src/rebar_app_discover.erl
index 21dea29..0c97ad7 100644
--- a/src/rebar_app_discover.erl
+++ b/src/rebar_app_discover.erl
@@ -52,7 +52,7 @@ do(State, LibDirs) ->
                         Name = rebar_app_info:name(AppInfo),
                         case enable(State, AppInfo) of
                             true ->
-                                {AppInfo1, StateAcc1} = merge_opts(AppInfo, StateAcc),
+                                {AppInfo1, StateAcc1} = merge_opts(TopLevelApp, AppInfo, StateAcc),
                                 OutDir = filename:join(DepsDir, Name),
                                 AppInfo2 = rebar_app_info:out_dir(AppInfo1, OutDir),
                                 ProjectDeps1 = lists:delete(Name, ProjectDeps),
@@ -91,9 +91,9 @@ format_error({missing_module, Module}) ->
 %% some configuration like erl_opts must be merged into a subapp's opts
 %% while plugins and hooks need to be kept defined to only either the
 %% top level state or an individual application.
--spec merge_opts(rebar_app_info:t(), rebar_state:t()) ->
+-spec merge_opts(root | binary(), rebar_app_info:t(), rebar_state:t()) ->
     {rebar_app_info:t(), rebar_state:t()}.
-merge_opts(AppInfo, State) ->
+merge_opts(TopLevelApp, AppInfo, State) ->
     %% These steps make sure that hooks and artifacts are run in the context of
     %% the application they are defined at. If an umbrella structure is used and
     %% they are defined at the top level they will instead run in the context of
@@ -104,7 +104,12 @@ merge_opts(AppInfo, State) ->
     Name = rebar_app_info:name(AppInfo1),
 
     %% We reset the opts here to default so no profiles are applied multiple times
-    AppInfo2 = rebar_app_info:apply_overrides(rebar_state:get(State1, overrides, []), AppInfo1),
+    AppInfo2 = case TopLevelApp of
+        Name -> % don't apply to the root app
+            AppInfo;
+        _ -> % apply overrides when in an umbrella project or on deps
+            rebar_app_info:apply_overrides(rebar_state:get(State1, overrides, []), AppInfo1)
+    end,
     AppInfo3 = rebar_app_info:apply_profiles(AppInfo2, CurrentProfiles),
 
     %% Will throw an exception if checks fail