Upgrading and downgrading

How to Upgrade

If you are running an older version, shut it down. Wait until it has completely shut down (which might take a few minutes for older versions), then run the installer (on Windows) or just copy over /Applications/Bitcoin-Qt (on Mac) or bitcoind/bitcoin-qt (on Linux).

If you are upgrading from version 0.7.2 or earlier, the first time you run 0.9.3 your blockchain files will be re-indexed, which will take anywhere from 30 minutes to several hours, depending on the speed of your machine.

Downgrading warnings

The ‘chainstate’ for this release is not always compatible with previous releases, so if you run 0.9.x and then decide to switch back to a 0.8.x release you might get a blockchain validation error when starting the old release (due to ‘pruned outputs’ being omitted from the index of unspent transaction outputs).

Running the old release with the -reindex option will rebuild the chainstate data structures and correct the problem.

Also, the first time you run a 0.8.x release on a 0.9 wallet it will rescan the blockchain for missing spent coins, which will take a long time (tens of minutes on a typical machine).

0.9.3 Release notes

RPC:

• Avoid a segfault on getblock if it can’t read a block from disk
• Add paranoid return value checks in base58

Protocol and network code:

• Don’t poll showmyip.com, it doesn’t exist anymore
• Add a way to limit deserialized string lengths and use it
• Add a new checkpoint at block 295,000
• Increase IsStandard() scriptSig length
• Avoid querying DNS seeds, if we have open connections
• Remove a useless millisleep in socket handler
• Stricter memory limits on CNode
• Better orphan transaction handling
• Add -maxorphantx=<n> and -maxorphanblocks=<n> options for control over the maximum orphan transactions and blocks

Wallet:

• Check redeemScript size does not exceed 520 byte limit
• Ignore (and warn about) too-long redeemScripts while loading wallet

GUI:

• fix ‘opens in testnet mode when presented with a BIP-72 link with no fallback’
• AvailableCoins: acquire cs_main mutex
• Fix unicode character display on MacOSX

Miscellaneous:

• key.cpp: fail with a friendlier message on missing ssl EC support
• Remove bignum dependency for scripts
• Upgrade OpenSSL to 1.0.1i (see https://www.openssl.org/news/secadv_20140806.txt - just to be sure, no critical issues for Bitcoin Core)
• Upgrade miniupnpc to 1.9.20140701
• Fix boost detection in build system on some platforms

Credits

Thanks to everyone who contributed to this release:

• Andrew Poelstra
• Cory Fields
• Gavin Andresen
• Jeff Garzik
• Johnathan Corgan
• Julian Haight
• Michael Ford
• Pavel Vasin
• Peter Todd
• phantomcircuit
• Pieter Wuille
• Rose Toomey
• Ruben Dario Ponticelli
• shshshsh
• Trevin Hofmann
• Warren Togami
• Wladimir J. van der Laan
• Zak Wilcox

As well as everyone that helped translating on Transifex.