Bugfix for #1850

[xordoquy]

No description provided.

[tomchristie]

So what's the upshot of this change then?
Does caching middleware work after this change?
Does anything else potentially break after the change, and what?

[paschembri]

I tried this and when caching is enabled (whole site) it does not work.

[xordoquy]

@paschembri do you have a code sample we could test against ?
I remember I tried on a "real" api and remove the _closable_objects fixed it (which is basically what this PR is about).

[paschembri]

Actually the exact setup for the application (that fails with caching enabled) is :
1 x Model => 1 x Serializer (HyperlinkedModelSerializer) => 1 x Collection view (ListCreateAPIView)

But the tricky thing to observe the failure is to use several http clients, I was working with firefox and the developer console (caching enabled server-side) then I tried accessing the api using another browser (so no cookies, no client cache control) and that's when it failed. I did not have to change the ip address to observe the failure.
The message is the one of issue 1850 (no _closable_objects).

EDIT:
The cache management is done using memcached

EDIT2 :
The issue is not raised with a dummycache

[paschembri]

Ok, something is strange, I just tried again to enable cache on the app and now it's working (with the proposed patch). I believe it was late when I was working on this.
I have an api running on public.netsach.com and I enabled caching (with the proposed patch).
Can you try it with several browser (with an open console so you can see if there is 500 errors) ?

[xordoquy]

Seems to work from here.

[paschembri]

I guess the patch works as expected