Since 0.8.x many MacOS X users have been experiencing periodic leveldb data corruption issues.  While not fatal, it is very time consuming to recover from this corruption and upsetting that it happens often for some users.  There have been three commits in Bitcoin that attempted to fix this, one fsync fix in leveldb, one in util.h, and a leveldb version upgrade to 1.13.  My guess is that one of these commits fixed other corruption, but there remains at least one mysterious corruption issue on Mac where leveldb is corrupted after a clean shutdown of Bitcoin-Qt.  After 5+ months we still do not know why some users never see corruption while it happens often for others.

Gavin has pledged 5 BTC, and Litecoin Dev pledges 200 LTC to start this bounty.  This thread has public addresses for Mac users to donate to increase the incentive to fix this issue sooner.

To help please contribute detailed bug reports or links to more relevant background information pertaining to this corruption issue.

https://bitcointalk.org/index.php?topic=320695.0

For testing purposes, please use either Bitcoin git master or Bitcoin 0.8.5 OMG3, both of which contain all of the relevant leveldb fixes.  Testing without those fixes will not be helpful at this point.

Warren