in the query cache. (Bug #9549)


libmysqld/emb_qcache.h:
  Fix Querycache_stream::use_next_block() to actually use the next
  block and mark blocks as used when it writes to them.
mysql-test/r/query_cache.result:
  Update results.
mysql-test/t/query_cache.test:
  Add new regression test.
libmysqld/emb_qcache.cc:
  Fix calls to use_next_block() to indicate whether we are writing
  to the next block or not.
sql/sql_cache.cc:
  Initialize the first block properly when storing a result in
  the embedded server.