fix: avoid crash when jekyll-archives.layouts is not a hash

lib/jekyll-archives/archive.rb

@@ -47,14 +47,16 @@ def initialize(site, title, type, posts)
       #
       # Returns the template String.
       def template
-        @config.dig("permalinks", type)
+        permalinks = @config["permalinks"]
+        permalinks[type] if permalinks.is_a?(Hash)
       end
 
       # The layout to use for rendering
       #
       # Returns the layout as a String
       def layout
-        @config.dig("layouts", type) || @config["layout"]
+        layouts = @config["layouts"]
+        (layouts[type] if layouts.is_a?(Hash)) || @config["layout"]
       end
 
       # Returns a hash of URL placeholder names (as symbols) mapping to the

test/test_jekyll_archives.rb

@@ -133,6 +133,25 @@ class TestJekyllArchives < Minitest::Test
     end
   end
 
+
+  context "the jekyll-archives plugin with malformed layouts config" do
+    setup do
+      @site = fixture_site(
+        "jekyll-archives" => {
+          "enabled" => true,
+          "layouts" => "archive-too",
+        }
+      )
+    end
+
+    should "fall back to the default layout instead of crashing" do
+      @site.process
+
+      assert_equal "Test", read_file("/2014/index.html")
+      assert_equal "Test", read_file("/tag/test-tag/index.html")
+    end
+  end
+
   context "the archives" do
     setup do
       @site = fixture_site("jekyll-archives" => {