FIX: should be able to serve optimized image from local if its ... local...

app/controllers/user_avatars_controller.rb

@@ -67,7 +67,7 @@ class UserAvatarsController < ApplicationController
       original = Discourse.store.path_for(upload)
       if Discourse.store.external? || File.exists?(original)
         if optimized = get_optimized_image(upload, size)
-          if Discourse.store.external?
+          unless optimized.local?
             expires_in 1.day, public: true
             return redirect_to optimized.url
           end

app/models/optimized_image.rb

@@ -83,6 +83,10 @@ class OptimizedImage < ActiveRecord::Base
     end
   end
 
+  def local?
+   !(url =~ /^(https?:)?\/\//)
+  end
+
   def self.resize_instructions(from, to, dimensions, opts={})
     # NOTE: ORDER is important!
     %W{

spec/models/optimized_image_spec.rb

@@ -5,6 +5,21 @@ describe OptimizedImage do
   let(:upload) { build(:upload) }
   before { upload.id = 42 }
 
+  describe ".local?" do
+
+    def local(url)
+      OptimizedImage.new(url: url).local?
+    end
+
+    it "correctly detects local vs remote" do
+      expect(local("//hello")).to eq(false)
+      expect(local("http://hello")).to eq(false)
+      expect(local("https://hello")).to eq(false)
+      expect(local("https://hello")).to eq(false)
+      expect(local("/hello")).to eq(true)
+    end
+  end
+
   describe ".create_for" do
 
     context "when using an internal store" do