Fix Scss#sass_dir_relative_to_site_source logic

lib/jekyll/converters/scss.rb

@@ -123,7 +123,9 @@ def user_sass_load_paths
       end
 
       def sass_dir_relative_to_site_source
-        Jekyll.sanitized_path(site_source, sass_dir)
+        @sass_dir_relative_to_site_source ||= begin
+          Jekyll.sanitized_path(site_source, sass_dir).sub(site.source + "/", "")
+        end
       end
 
       # rubocop:disable Metrics/AbcSize
@@ -137,7 +139,7 @@ def sass_load_paths
 
         # Expand file globs (e.g. `node_modules/*/node_modules` )
         Dir.chdir(site_source) do
-          paths = paths.flat_map { |path| Dir.glob(path) }.uniq
+          paths = paths.flat_map { |path| Dir.glob(path) }
 
           paths.map! do |path|
             if safe?
@@ -149,6 +151,7 @@ def sass_load_paths
           end
         end
 
+        paths.uniq!
         paths << site.theme.sass_path if site.theme&.sass_path
         paths.select { |path| File.directory?(path) }
       end

spec/[alpha]beta/_config.yml

@@ -0,0 +1,3 @@
+sass:
+  style: :compressed
+highlighter: rouge

spec/[alpha]beta/_sass/_color.scss

@@ -0,0 +1,2 @@
+$black: #999;
+a { color: $black }

spec/[alpha]beta/_sass/_grid.scss

@@ -0,0 +1 @@
+.half { width: 50% }

spec/[alpha]beta/css/main.scss

@@ -0,0 +1,4 @@
+---
+---
+
+@import "grid";

spec/sass_converter_spec.rb

@@ -95,4 +95,22 @@ def converter(overrides = {})
       expect(verter.convert(content)).to eql(css_output)
     end
   end
+
+  context "in a site nested inside directory with square brackets" do
+    let(:site) do
+      make_site(
+        "source" => File.expand_path("[alpha]beta", __dir__),
+        "sass"   => {
+          "style" => :compact,
+        }
+      )
+    end
+
+    let(:verter) { sass_converter_instance(site) }
+
+    it "produces CSS without raising errors" do
+      expect { site.process }.not_to raise_error
+      expect(verter.convert(content)).to eql(css_output)
+    end
+  end
 end

spec/scss_converter_spec.rb

@@ -81,7 +81,7 @@ def converter(overrides = {})
         it "not allow sass_dirs outside of site source" do
           expect(
             converter("sass_dir" => "/etc/passwd").sass_dir_relative_to_site_source
-          ).to eql(source_dir("etc/passwd"))
+          ).to eql("etc/passwd")
         end
       end
     end
@@ -356,4 +356,22 @@ def converter(overrides = {})
       expect(verter.convert(content)).to eql(css_output)
     end
   end
+
+  context "in a site nested inside directory with square brackets" do
+    let(:site) do
+      make_site(
+        "source" => File.expand_path("[alpha]beta", __dir__),
+        "sass"   => {
+          "style" => :compact,
+        }
+      )
+    end
+
+    let(:verter) { scss_converter_instance(site) }
+
+    it "produces CSS without raising errors" do
+      expect { site.process }.not_to raise_error
+      expect(verter.convert(content)).to eql(css_output)
+    end
+  end
 end