[squid-users] stale-if-error combined with stale-while-revalidate not working as expected after 2.7 stable6

Hi to all

we use squid 2.7 as Reverse Proxy

stale-if-error combined with stale-while-revalidate not working as
expected after 2.7 stable6

Using both cache-control headers stale-if-error and
stale-while-revalidate when the peer returns 5xx squid does not serve
stale content anymore but the 5xx page to the client

we using this cache headers (Cache-control: public, max-age=5,
stale-while-revalidate=600, stale-if-error=3600)

************
using squid 2.7 STABLE7, squid 2.7 STABLE8, squid 2.7 STABLE9
when the peer returns 5xx

     -logfile output
  TCP_ASYNC_MISS:SOURCEHASH_PARENT "GET http://www.site.com/ HTTP/1.1"
503 165
  TCP_MISS:SOURCEHASH_PARENT "GET http://www.site.com/ HTTP/1.1" 503 231

-------------------

using squid 2.7 STABLE6 when the peer returns 5xx

     -logfile output
TCP_ASYNC_MISS:SOURCEHASH_PARENT "GET http://www.site.com/ HTTP/1.1"
503 165
TCP_NEGATIVE_HIT:FIRST_UP_PARENT "GET http://www.site.com/ HTTP/1.1" 200
59460

removing stale-while-revalidate and using this cache headers
(Cache-control: public, max-age=5, stale-if-error=3600) stale-if-error
works as expected!! but we loose the benefit of cache directive
stale-while-revalidate!!!!

is this a known bug?

-- 
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George Halkias