FIX: Allow shared CDN for s3 and assets

app/models/upload.rb

@@ -77,7 +77,7 @@ class Upload < ActiveRecord::Base
   def self.get_from_url(url)
     return if url.blank?
     # we store relative urls, so we need to remove any host/cdn
-    url = url.sub(Discourse.asset_host, "") if Discourse.asset_host.present?
+    url = url.sub(Discourse.asset_host, "") if Discourse.asset_host.present? && Discourse.asset_host != SiteSetting.Upload.s3_cdn_url
     # when using s3, we need to replace with the absolute base url
     url = url.sub(SiteSetting.Upload.s3_cdn_url, Discourse.store.absolute_base_url) if SiteSetting.Upload.s3_cdn_url.present?
 

spec/models/upload_spec.rb

@@ -111,6 +111,22 @@ describe Upload do
 
         expect(Upload.get_from_url(URI.join(s3_cdn_url, path).to_s)).to eq(upload)
       end
+
+      it "should return the right upload when using one CDN for both s3 and assets" do
+        begin
+          original_asset_host = Rails.configuration.action_controller.asset_host
+          cdn_url = 'http://my.cdn.com'
+          Rails.configuration.action_controller.asset_host = cdn_url
+          SiteSetting.s3_cdn_url = cdn_url
+          upload
+
+          expect(Upload.get_from_url(
+            URI.join(cdn_url, path).to_s
+          )).to eq(upload)
+        ensure
+          Rails.configuration.action_controller.asset_host = original_asset_host
+        end
+      end
     end
   end