rebar_core: fix consistency issues caused by 252b31f

- refactor plugin dirs code to be simpler and easier to read
- use erlang-mode's default (%%) comments for portability/consistency
- make sure erlang-mode's indenter is used so that a future whole
  buffer indent doesn't get messed up

src/rebar_core.erl

@@ -533,21 +533,7 @@ plugin_modules(Config, PredirsAssoc, FoundModules, MissingModules) ->
 
 load_plugin_modules(Config, PredirsAssoc, Modules) ->
     Cwd = rebar_utils:get_cwd(),
-    PluginDirs = case rebar_config:get_local(Config, plugin_dir, undefined) of
+    PluginDirs = get_all_plugin_dirs(Config, Cwd, PredirsAssoc),
-        undefined ->
-            % Plugin can be in the project's "plugins" folder
-            [filename:join(Cwd, "plugins")];
-        Dir ->
-            [Dir]
-    end ++
-    % We also want to include this case:
-    % Plugin can be in "plugins" directory of the plugin base directory. For
-    % example, Cwd depends on Plugin, and deps/Plugin/plugins/Plugin.erl is the
-    % plugin.
-    [
-        filename:join(Dir, "plugins") ||
-        Dir <- get_plugin_base_dirs(Cwd, PredirsAssoc)
-    ],
 
     %% Find relevant sources in base_dir and plugin_dir
     Erls = string:join([atom_to_list(M)++"\\.erl" || M <- Modules], "|"),
@@ -562,12 +548,32 @@ load_plugin_modules(Config, PredirsAssoc, Modules) ->
     NotLoaded = [V || V <- Modules, FilterMissing(V)],
     {Loaded, NotLoaded}.
 
+get_all_plugin_dirs(Config, Cwd, PredirsAssoc) ->
+    get_plugin_dir(Config, Cwd) ++ get_base_plugin_dirs(Cwd, PredirsAssoc).
+
+get_plugin_dir(Config, Cwd) ->
+    case rebar_config:get_local(Config, plugin_dir, undefined) of
+        undefined ->
+            %% Plugin can be in the project's "plugins" folder
+            [filename:join(Cwd, "plugins")];
+        Dir ->
+            [Dir]
+    end.
+
+%% We also want to include this case:
+%% Plugin can be in "plugins" directory of the plugin base directory.
+%% For example, Cwd depends on Plugin, and deps/Plugin/plugins/Plugin.erl
+%% is the plugin.
+get_base_plugin_dirs(Cwd, PredirsAssoc) ->
+    [filename:join(Dir, "plugins") ||
+        Dir <- get_plugin_base_dirs(Cwd, PredirsAssoc)].
+
 %% @doc PredirsAssoc is a dictionary of plugindir -> 'parent' pairs
 %% 'parent' in this case depends on plugin; therefore we have to give
 %% all plugins that Cwd ('parent' in this case) depends on.
 get_plugin_base_dirs(Cwd, PredirsAssoc) ->
     [PluginDir || {PluginDir, Master} <- dict:to_list(PredirsAssoc),
-        Master =:= Cwd].
+                  Master =:= Cwd].
 
 is_missing_plugin(Loaded) ->
     fun(Mod) -> not lists:member(Mod, Loaded) end.