In RequestProcessor, the cache key is constructed as such:
CacheKey = string.Join("/",
new[]
{
CachePrefix,
typeof (RequestProcessor).ToString(),
setName,
version,
Compressor.EncodingName
}.Concat(CacheVaryStates.Select(s => s.Key)).ToArray());
I believe that the current protocol (http vs https) should be considered when constructing this cache key.
I've run into problems with absolute paths and mixed content warnings when I assumed that:
http://blah.com/combres/set and
https://blah.com/combres/set would return entirely different resources (they should really, as they could represent entirely different content)