dotless/dotless — Issue #115: Missing Vary: Accept-Encoding
Author: Sarkie
Created: 2012-01-27 11:51:16+00:00
State: open

As to add to my previous report.

http://stackoverflow.com/questions/7848796/what-does-varyaccept-encoding-mean

The logic you are reading is backwards, the article is saying if you are returning a compressed format, which you are in LessCssHttpHandler, you need to tell that the response changes based on the Requests Accept-Encoding, without it.

User a : Hi, I support, GZIP and Deflate.
Proxy1: I have nothing yet
Server: Ok here's a cacheable resource, encoded with Deflate
Proxy1: Ok thanks, well I'll cache that response on the proxy.
User a: Thanks perfect.
User b: Hi, I support nothing!
Proxy1: Oh well I have that resource cached and it doesn't vary on anything, here's the cached resource
User a: I can't read this?!? (Its in deflate).

This is my take on Vary and caching.