Include cdn path in the stylesheet digest.

lib/sass/discourse_stylesheets.rb

@@ -59,7 +59,7 @@ class DiscourseStylesheets
   def self.max_file_mtime
     globs = ["#{Rails.root}/app/assets/stylesheets/**/*.*css"]
 
-    for path in (Discourse.plugins || []).map { |plugin| File.dirname(plugin.path) }
+    Discourse.plugins.map { |plugin| File.dirname(plugin.path) }.each do |path|
       globs += [
         "#{path}/plugin.rb",
         "#{path}/**/*.*css",
@@ -71,8 +71,6 @@ class DiscourseStylesheets
     end.compact.max.to_i
   end
 
-
-
   def initialize(target = :desktop)
     @target = target
   end
@@ -167,7 +165,13 @@ class DiscourseStylesheets
       if theme || category_updated > 0
         Digest::SHA1.hexdigest "#{RailsMultisite::ConnectionManagement.current_db}-#{theme}-#{DiscourseStylesheets.last_file_updated}-#{category_updated}"
       else
-        Digest::SHA1.hexdigest "defaults-#{DiscourseStylesheets.last_file_updated}"
+        digest_string = "defaults-#{DiscourseStylesheets.last_file_updated}"
+
+        if cdn_url = GlobalSetting.cdn_url
+          digest_string = "#{digest_string}-#{cdn_url}"
+        end
+
+        Digest::SHA1.hexdigest digest_string
       end
     end
   end

spec/components/discourse_stylesheets_spec.rb

@@ -29,4 +29,18 @@ describe DiscourseStylesheets do
     end
   end
 
+  describe "#digest" do
+    before do
+      described_class.expects(:max_file_mtime).returns(Time.new(2016, 06, 05, 12, 30, 0, 0))
+    end
+
+    it "should return a digest" do
+      expect(described_class.new.digest).to eq('0e6c2e957cfc92ed60661c90ec3345198ccef887')
+    end
+
+    it "should include the cdn url when generating the digest" do
+      GlobalSetting.expects(:cdn_url).returns('https://fastly.maxcdn.org')
+      expect(described_class.new.digest).to eq('4995163b1232c54c8ed3b44200d803a90bc47613')
+    end
+  end
 end