Revision 1805336

Create a backport branch for r1805301 (Fix for an endless loop in the
deflate bucket with the truncated input).

Since the deflate bucket has been heavily tweaked in trunk, the fix
required adjustment.  The test required a couple of tweaks as well.

* buckets/deflate_buckets.c
  (serf_deflate_read): Handle a case when we hit the end of input
   stream and zlib can't continue, even though there's enough output
   space.  If that happens, return an error.

* test/test_buckets.c
  (test_deflate_bucket_truncated_data): New test, fails without the fix.
  (test_buckets): Add new test.