[Varnish] #1761: 204 responses intermittently delivered as chunk-encoded with length byte = 0

[Varnish]

#1761: 204 responses intermittently delivered as chunk-encoded with length byte =
0
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 Reporter:  geoff     |       Owner:  geoff
     Type:  defect    |      Status:  reopened
 Priority:  normal    |   Milestone:  Varnish 4.0 release
Component:  varnishd  |     Version:  4.0.3
 Severity:  normal    |  Resolution:
 Keywords:            |
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Comment (by geoff):

 Unfortunately I don't have a test case, because we never discovered how to
 reliably reproduce the problem. So I couldn't create a vtc that would fail
 unless the patch is applied.

 I'm confident that the patch resolves the problem, because it never
 happened again after we applied it in production.

 FWIW, the patch is a one-liner: set the wantbody flag to 0 when the
 response code was 204 (previously done only when the response is 304) --
 this is one of the things that happens in phk's patch for what is now 4.1.
 For the reasons described in the second comment, I think this has to be
 the solution. But I'm afraid I can't prove it with a vtc, only from our
 experience of a bug being there and then going away.

 @martin, what should we do?

-- 
Ticket URL: <https://www.varnish-cache.org/trac/ticket/1761#comment:11>
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