Bitcoin-Qt 0.5.3
================

Bitcoin version 0.5.3 is now available for download at:
<http://sourceforge.net/projects/bitcoin/files/Bitcoin/bitcoin-0.5.3/>

This is a bugfix-only release based on 0.5.1.
It also includes a few protocol updates.

Please report bugs using the issue tracker at github:
<https://github.com/bitcoin/bitcoin/issues>

Stable source code is hosted at Gitorious:
http://gitorious.org/bitcoin/bitcoind-stable/archive-tarball/v0.5.3#.tar.gz

PROTOCOL UPDATES
----------------

* BIP 30: Introduce a new network rule: "a block is not valid if it contains a transaction whose hash already exists in the block chain, unless all that transaction's outputs were already spent before said block" beginning on March 15, 2012, 00:00 UTC.
* On testnet, allow mining of min-difficulty blocks if 20 minutes have gone by without mining a regular-difficulty block. This is to make testing Bitcoin easier, and will not affect normal mode.

BUG FIXES
---------

* Limit the number of orphan transactions stored in memory, to prevent a potential denial-of-service attack by flooding orphan transactions. Also never store invalid transactions at all.
* Fix possible buffer overflow on systems with very long application data paths. This is not exploitable.
* Resolved multiple bugs preventing long-term unlocking of encrypted wallets (issue #922).
* Only send local IP in "version" messages if it is globally routable (ie, not private), and try to get such an IP from UPnP if applicable.
* Reannounce UPnP port forwards every 20 minutes, to workaround routers expiring old entries, and allow the -upnp option to override any stored setting.
* Skip splash screen when -min is used, and fix Minimize to Tray function.
* Do not blank "label" in Bitcoin-Qt "Send" tab, if the user has already entered something.
* Correct various labels and messages.
* Various memory leaks and potential null pointer deferences have been fixed.
* Handle invalid Bitcoin URIs using "bitcoin://" instead of "bitcoin:".
* Several shutdown issues have been fixed.
* Revert to "global progress indication", as starting from zero every time was considered too confusing for many users.
* Check that keys stored in the wallet are valid at startup, and if not, report corruption.
* Enable accessible widgets on Windows, so that people with screen readers such as NVDA can make sense of it.
* Various build fixes.
* If no password is specified to bitcoind, recommend a secure password.
* Automatically focus and scroll to new "Send coins" entries in Bitcoin-Qt.
* Show a message box for --help on Windows, for Bitcoin-Qt.
* Add missing "About Qt" menu option to show built-in Qt About dialog.
* Don't show "-daemon" as an option for Bitcoin-Qt, since it isn't available.
* Update hard-coded fallback seed nodes, choosing recent ones with long uptime and versions at least 0.4.0.
* Add checkpoint at block 168,000.
