FIX: Multiple links being generated for non-theme targets.

Follow-up to 8e3691d537

lib/stylesheet/manager.rb

@@ -201,8 +201,9 @@ class Stylesheet::Manager
     @@lock.synchronize do
       stylesheets = []
       stale_theme_ids = []
+      theme_ids = target.to_s =~ THEME_REGEX ? @theme_ids : [@theme_id]
 
-      @theme_ids.each do |theme_id|
+      theme_ids.each do |theme_id|
         cache_key = "path_#{target}_#{theme_id}_#{current_hostname}"
 
         if href = cache[cache_key]

spec/components/stylesheet/manager_spec.rb

@@ -38,6 +38,14 @@ describe Stylesheet::Manager do
       t.add_relative_theme!(:child, child_theme)
     }}
 
+    it "generates the right links for non-theme targets" do
+      manager = manager(theme.id)
+
+      hrefs = manager.stylesheet_details(:desktop, 'all')
+
+      expect(hrefs.length).to eq(1)
+    end
+
     it 'can correctly compile theme css' do
       manager = manager(theme.id)
       old_links = manager.stylesheet_link_tag(:desktop_theme, 'all')