If the variable dkey.mv_size is non-zero, then it means dkey
contains some original data which has to be put back in the
child db, typically when the child db has just been created.

But when using MDB_MULTIPLE, if this variable has not been
reset to zero, we may come back to this section and wrongly
think that there is some original data to be taken care of.

Howard Chu authored Mar 18, 2013 and Quanah Gibson-Mount committed Mar 18, 2013

typos in quicksort

Howard Chu authored Mar 14, 2013 and Quanah Gibson-Mount committed Mar 18, 2013

Was already being checked for other message types.

Allow leaf pages to have only 1 key.

Causes Bus Error on SPARC

Android supports madvise but not posix_madvise

Add missing parens

It's harmful when the DB is larger than RAM.

A page must always have at least 2 keys (unless it's a root page)