[Varnish] #795: Conditional GETs based on modification time are not honored if Last-Modified was not explicitly set

[Varnish]

#795: Conditional GETs based on modification time are not honored if Last-
Modified was not explicitly set
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  Reporter:  runa    |        Type:  defect
    Status:  closed  |    Priority:  normal
 Milestone:          |   Component:  build 
   Version:  2.0     |    Severity:  normal
Resolution:  fixed   |    Keywords:        
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Comment(by tfheen):

 (In [5613]) Merge r5505: Change how we do If-Modified-Since on objects
 without a Last-Modified header.

 Until now, we have not allowed IMS on objects without LM header but
 after due consideration of our role as web-server, that restriction is
 found too hard: Varnish will, by definition, not find and object which
 is not valid, so we can trust the time we put it into the cache to be
 the LM date.

 But we can not synthesize a LM header based on this, as this would
 allow down-stream client-side caches to make unwarranted decisions
 (see RFC2616 13.3.4 p88)

 Fixes: #795

-- 
Ticket URL: </ticket/795#comment:4>
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