Bitcoin Forum

Bitcoin-Qt version 0.8.6 final is now available from:

  http://sourceforge.net/projects/bitcoin/files/Bitcoin/bitcoin-0.8.6/ (http://sourceforge.net/projects/bitcoin/files/Bitcoin/bitcoin-0.8.6/)

This is a maintenance release to fix a critical bug; we urge all users to upgrade.

Please report bugs using the issue tracker at github:

  https://github.com/bitcoin/bitcoin/issues (https://github.com/bitcoin/bitcoin/issues)

How to Upgrade
--------------

If you already downloaded 0.8.6rc1 you do not need to re-download. This release is exactly the same.

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 0.8.6 your blockchain files will be re-indexed, which will take
anywhere from 30 minutes to several hours, depending on the speed of
your machine.

0.8.6 Release notes
===================

- Default block size increase for miners.
  (see https://gist.github.com/gavinandresen/7670433#086-accept-into-block)

- Remove the all-outputs-must-be-greater-than-CENT-to-qualify-as-free rule for relaying
  (see https://gist.github.com/gavinandresen/7670433#086-relaying)

- Lower maximum size for free transaction creation
  (see https://gist.github.com/gavinandresen/7670433#086-wallet)

- OSX block chain database corruption fixes
  - Update leveldb to 1.13
  - Use fcntl with `F_FULLSYNC` instead of fsync on OSX
  - Use native Darwin memory barriers
  - Replace use of mmap in leveldb for improved reliability (only on OSX)

- Fix nodes forwarding transactions with empty vins and getting banned

- Network code performance and robustness improvements

- Additional debug.log logging for diagnosis of network problems, log timestamps by default

- Fix Bitcoin-Qt startup crash when clicking dock icon on OSX

- Fix memory leaks in CKey::SetCompactSignature() and Key::SignCompact()

- Fix rare GUI crash on send

- Various small GUI, documentation and build fixes

Warning
-------

- There have been frequent reports of users running out of virtual memory on 32-bit systems
  during the initial sync.
  Hence it is recommended to use a 64-bit executable if possible.
  A 64-bit executable for Windows is planned for 0.9.

Note: Gavin Andresen's GPG signing key for SHA256SUMS.asc has been changed from  key id 1FC730C1 to sub key 7BF6E212 (see https://github.com/bitcoin/bitcoin.org/pull/279).

Sourceforge page still reads

Definitely looking for feedback -- good or bad -- from OSX users in particular.  You may have to -reindex to fix the prior corruption issues that impacted earlier versions.

For anyone downloading a fresh copy of the blockchain from scratch, please consider downloading the Bitcoin blockchain torrent (https://bitcointalk.org/index.php?topic=145386.0).

I'm running headless bitcoind on the Electrum server foundry ( http://foundry.electrum.org ) without problems. It all works as expected. It's nice to see some proper timestamps in the debug.log now.

One thing I noticed:
2013-12-09 14:22:59 Bitcoin version v0.8.6.0-g03a7d67-beta ()

-beta is probably not intended for a production release?

The -beta has been there in every release since the beginning.

BITCOIN IS IN BETA
Why do people forget this?

(not only are these the "early days" there are many "early days" to come)

Just downloaded on OSX Snow Leopard. Still doing block verification. Stay tuned.
Does this version expose any of the new Identity work?

Who signed the SHA256SUMS.asc? Key ID 7BF6E212. Normally they are signed by Gavin's Code Signing key 1FC730C1. I just doubled checked 0.8.5 and that is the case. Why the change in the signing key without any notification?

Also the Windows executable has not been signed by The Foundation. What is going on here?

Edit: Looks like it is a subkey - https://github.com/bitcoin/bitcoin.org/pull/279
I would kindly suggest the release notes be edited to document this change as both differences happening with no warning is a bit scary.

i'll wait for the 64-bit version.

Seems to run fine on OSX Snow Leopard. Took a while to sync as I hadn't run old version in a few days, and really burned up the CPU for a good hour doing it. Otherwise all good and shut down without incident as well.

Is there any chance for future releases that the upload bandwidth used by bitcoind could have a throttle option?

I don't have one of these new fangled VDSL or Cable connections, I have a 8mbit ADSL connection with a staggering 256k upstream. It gives me an upload speed of 38kb/s. Bitcoin-qt sucks up all of that bandwidth which makes even browsing webpages extremely slow and painful, sometimes impossible. It would be nice if there was an option (other than 'exit') so that bitcoin-qt couldn't hijack my internet connection.

Bah, I forgot to code-sign the Windows .exe. Expect an updated .exe and SHASUMS soon.

Working fine so far on MacOS 10.9 Mavericks. (Though, the prior versions did for me as well.)

And I concur that it'd be nice to have a heads up that the GPG signing key had changed. My GPG downloaded and verified the new key, but it was a little unexpected.

Thanks for all the work you guys put into this experiment!

Seems to sync faster on 10.9 OS X, also no problems here.

Thanks Gavin!

When you update the client do your bitcoins on the client stay intact?

Yes. But as always, backup your wallet.dat regularly to make sure a freak accident doesn't lose your coins.

I've added a note to the forum post.

Version 0.8.6 installed (over 0.8.5) succesfully in OSX 10.8.5 (Hackintosh) with an encrypted wallet. All ok. Thanks!

Electrum was made for you. You can also limit the connections from a long time ago.

bitcoin y u no checkpoint??

>getblockcountsincecheckpoint
24258

There is a Linux script in contrib/qos that allows throttling the outgoing bandwidth for connections on the Bitcoin network.
For other operating systems, there are likely similar ways to throttle certain applications/ports.

Yay I can finally combine my smaller amounts of BTC!

What is the secret to validating the download with the signature?  I am used to verifying files having a download file say file.tar.gz and then a file.tar.gz.asc and running:
after importing the authors public key.  However with bitcoin-qt the signature file SHA256SUMS.asc seems to have signature data for all the different versions of bitcoin-qt.  When I import Gavin Andresen's public key and run:
I get "Good signature" no matter what.  For instance if I completely delete bitcoin-0.8.6-linux.tar.gz I still get "Good signature"  if I create a blank file called bitcoin-0.8.6-linux.tar.gz I still get "Good signature".  It's as if it isn't actually verifying against the bitcoin-0.8.6-linux.tar.gz file.  What am I doing wrong?

I've looked around and can't find an answer regarding transaction fees paid by qt client.  It seems like sometimes it asks for a trnasaction fee and sometimes it doesn't, and sometimes it says it's going to be one fee and then it's less when I confirm I want to do it.  Finally I have heard you can do slower transactions for less fee but I can't find how to do this.  Thanks

First, you check that the downloaded file match the SHA-256 checksum in SHA256SUMS.asc

Then you check that SHA256SUMS.asc itself has not been tampered with

When will come to the Ubuntu repository ?

I just want to thank all of you for helping me with these issues. I am very new to this and I feel like the posters here are very helpful! Keep it up!!!

So I downloaded this for use with OSX 10.9.

I added the app to the Applications folder after verifying the sig. As a shortcut, I copied accross the 'blocks' and 'chainstate' folders from a VM I had running bitcoind on Ubuntu 13.04.

I then opened the Bitcoin-Qt 0.8.6, which 'hung' at the "Opening wallet" splashscreen, for about 24 hours. Luckily I could see in the console debug.log that it was just verifying the blocks, but to go from ~160,000 (where it started) to ~274,000 (where we are now) took 24hours using >700% CPU on an 8 core i7 (Ivy Bridge). Not sure if this is normal behaviour/speed as normally I sync from the network most of the blocks...? I woudl appreciate if anyone would like to comment on this time taken...

It then proceeded to work as expected. I have closed and re-opened the app with no corruption, but have not yet powered the computer off (after safe shutdown) to see if I can then re-open without levelDB corruption.

Will update when I do this, but so far, thanks for this release!

This may not be entirely accurate for this latest release of Bitcoin-Qt (as it only just came out!) but will explain fees pretty nicely for ya!

http://bitcoinfees.com/

This is why a new checkpoint would have been nice with this release, full transaction signatures are only verified for transactions in blocks after the checkpoint. I would think that is an unusual amount of CPU time though.

Never. The Bitcoin devs specifically asked package managers not to.

Correct. It would be great to have the latest version in the package repositories but that's not how it works. Due to stable release policies and such they never keep it up to date.

Use the PPA, at least we have that under control ourselves. https://launchpad.net/~bitcoin/+archive/bitcoin

thanks to all!
bitcoind seems to be running fine on rk3188 ARM with latest p2pool, compilation failed with Fedora 19x64,will try later.
great work !

thank you !
just updated with your steps
everything went fine!!
welldone! :)

Looking at the release notes, I don't understand which of the changes fixes a critical bug. Is this one of the OS X specific changes, or is it about a bug that affects all platforms? What is the impact of the bug?

The blockchain getting corrupted and the program crashing when you start it or when you send money are kind of annoying...
This whole thread: https://bitcointalk.org/index.php?topic=337294.0

Release notes (https://github.com/bitcoin/bitcoin/commit/03a7d673876dc8fbae876290b455c02b0cac80bd)

+- Default block size increase for miners

+  (see https://gist.github.com/gavinandresen/7670433#086-accept-into-block)


+- Remove the all-outputs-must-be-greater-than-CENT-to-qualify-as-free rule for relaying

+  (see https://gist.github.com/gavinandresen/7670433#086-relaying)


+- Lower maximum size for free transaction creation

+  (see https://gist.github.com/gavinandresen/7670433#086-wallet)


+- OSX block chain database corruption fixes

+  - Update leveldb to 1.13

+  - Use fcntl with `F_FULLSYNC` instead of fsync on OSX

+  - Use native Darwin memory barriers

+  - Replace use of mmap in leveldb for improved reliability (only on OSX)


+- Fix nodes forwarding transactions with empty vins and getting banned

+- Network code performance and robustness improvements

+- Additional debug.log logging for diagnosis of network problems, log timestamps by default

+- Fix Bitcoin-Qt startup crash when clicking dock icon on OSX

+- Fix memory leaks in CKey::SetCompactSignature() and Key::SignCompact()

+- Fix rare GUI crash on send

+- Various small GUI, documentation and build fixes

OK, so just to be sure: if I understand correctly,

• This bug certainly affects OS X users, and possibly (but probably not) users of other platforms.
• The impact of the bug is that your local copy of the block chain gets corrupted, causing program crashes and generally making it impossible to use the software
• The bug does not lead to a wallet corruption, and it does not allow hackers to do nasty things, such as bitcoin theft or gaining access to your computer

I wanted to know this, because I follow certain procedures when upgrading to a new version, and this will take some time. Since I've been using 0.8.5 without problems on an non-OS X platform for a while, I think I can safely continue to do so, until I've finished the upgrade to 0.8.6.

There are a few sort-of critical bugs fixed. Transmitting empty transactions and getting banned is ugly. The rare crash-on-send in the GUI can also be quite nasty.

The OSX bug does not affect any other platforms.

Nice! Good fixes.

anyone have build instructions?

I will answer myself.


If anyone knows how to install compatible bdb libs on ubuntu using apt-get side by side with the existing ones, that would be helpful.

If i install this latest version will i need to download the whole blockchain again ? (took a whole day last time)

No, assuming you are upgrading from 0.8.5, it will use the same wallet and blockchain data.

Thanks

Hey Wumpus! Thanks for sharing the news of latest update of Bitcoin which is much better in all aspects then the previous version. These days I have heard a lot about bitcoin but really I don’t know how to buy the new digital currency name d bitcoin. Can you please provide some link that will be helpful for people like me?

I have a 64 bit OS.. when is the 64bit executable going to be released? I believe version 0.9  . What risk is present if I wait?

Which 64 bit OS?

64-bit executables are available for OSX and Linux.  Windows is coming soon.

  I have Windows 7, waiting for  X64 version, my biggest concern is the risk in waiting..

I don't think it makes sense to wait for 0.9 if your goal is risk minimization. Better to just go with 0.8.6.

0.9.0rc1 will be more risky when it is released, after all it contains a lot of new features and changes which have not been as extensively tested as the 0.8.x series. This will need some time to settle down too.

 Well I wouldn't have worried about problems but in the release news it states 'Warning
-------

- There have been frequent reports of users running out of virtual memory on 32-bit systems
  during the initial sync.
  Hence it is recommended to use a 64-bit executable if possible.
  A 64-bit executable for Windows is planned for 0.9.'


so a 64 bit exe would be appropriate for a 64 bit OS?

That's nothing new with 0.8.6 -- if 0.8.5 or earlier worked fine for you on 32 bit, 0.8.6 will too.
Also it appears that the virtual memory problems occur mainly for new initial block syncs.

0.8.6?

mine says it is 4.8.3

apparently I am from the future

oh...I am derp

thanks

wumpus thanks for sharing a vital information with us. I was desperately waiting for these fixes finally It’s been fixed by new upgrades. Great, I shall soon check these updates. Keep on sharing such important news with your fellows on this forum. Thanks ones again

How big the size of synchronization purse?

Thank you very much to tell us about the release of new version. I will definitely try the new version as I was already facing few problems. I hope this update will finally solve the bugs that were becoming a headache for me. Please keep on sharing such news with us we shall appreciate it 

I see people using .9 ???

That must be 0.8.99, which is the current master (on release, it will be 0.9).

Somewhat related:  The bitcoin blockchain torrent was just updated: https://bitcointalk.org/index.php?topic=145386.0

New users may find that valuable.

...You know better, and that's just down-right fishy. With your position in this community, that is just inappropriate and unacceptable.

Yay to speak freely :)

Upgraded from working 0.8.5 on OS X 10.7.5. on MacBook Pro 8.3.
New 0.8.6 crashes upon init - first and every time.
Downgrade back to 0.8.5 now has same failure upon init:


Opened incident on github, included entire Mac "Problem Report for Bitcoin-QT". Is there any additional info I might provide to the devs?

In the meantime, what can I try to restore operation?

You will want to be using the latest version on OSX, it resolves several problems on that platform.

Try restarting the new client with the rebuild database index option and let it process, by running this command from the terminal:

Hows everyone liking Version 0.8.6?

Love it.

Did it. Fixed it. Thanks.

Ok, This is embarrassing to ask but since I'm not seeing anyone else ask I'm just gonna. I'm afraid that if I upgrade I will lose my wallet addresses. That's why I've never upgraded Bitcoin-QT, I'm still running version 0.8.3. Am I just being unreasonable, or should I back up first? I've got a Mac.

Lol no

But you better be encrypted and backed up anyway. You really need to be updated. Policies change. And an older one almost forked us.

Answered my own question I think: wallet.dat is in the users/library/... folder so it won't be affected by the drag and drop of Bitcoin-QT.

Thanks! Gonna update now. I'd hate to get forked! I'm encrypted and backed up, but I've added addresses since the backup. I just backed up again.

Haha! That was seamless. I'm an idiot for never updating!

tks

When 64 bit version will be out?? Should i download the new version asap, am i in risk by not doing it?

one negative issue with Bitcoin-Qt v0.8.6 client, it takes more than 8 hours to sync the client with network on 120Mb/s connection, slightly very long process, I think the reason behind the data is based one server instead of several geo locations.

Look at your cpu usage while downloading, especially after reaching the "20 weeks behind" point. You will see CPU being the bottleneck. Bitcoin verifies the ECDSA signatures in every transaction to ensure they are authorized payments, only better CPU or code optimizations (https://bitcointalk.org/index.php?topic=3238.0) will really improve this.

I noticed that last weeks of sync taking more time and the software using almost 2GB of RAM.

Will this version be compatible with my token ring ethernet LAN configuration?

Wot??? Are you sending this message from 1990?

As long as your computer has a normal TCP/IP stack and can get on the Internet and run other Internet applications, Bitcoin should work.

They have the Internet on computers now? (https://www.youtube.com/watch?v=iuslWRCnbyA)

Can Bitcoin wallet support other coins like litecoin or Gogecoin at same time? As you know there are so many coins now.

If it does not support other coins, do you have any plan for it?

Or if no plan, is there another project that is working on a wallet that supports multiple coins?

Regards
Anlongsun

That's like asking if my Swiss bank account supports Nigerian Prince investment fund. Or if Fort Knox will also store my collection of pretty rocks.

These alt-coins are Bitcoin, with the most trivial of changes. They can be taken out at any time by 51% attack by existing miner hashrate or common computing resources. They have been killed in the past just for demonstration, but nobody seems to learn, so now they and their wannabe-rich creators are ignored. Only Namecoin is unique in offering a new feature that won't be included in Bitcoin, and it has a difficulty about 75% that of Bitcoin itself.

I have a couple of wallet questions.

1: If several small transactions make up the bulk of my bitcoin does that affect the kb size of a transaction when I send coins? While I'm at it what does determine the kb size?

2: I created a vanity address about a year ago I have not used it or imported it to my wallet. If I were to import the private public key pair into my QT wallet and for whatever reason the vanity private key is compromised can it be used to move all the coins in the wallet or just ones that have been sent to the vanity address? I'm assuming that each bitcoin address has it's own private key and if any one of the private keys gets compromised does it control all the coins in the wallet or just the ones directly associated with the compromised key pair?

Thanks...

i have a question. If there is a new version 0.8.6 is 0.8.5 still functioned?

No.


The number of inputs determines the kB size. So if you have a lot of small inputs (for example received from faucets or mining) and merge them to send a larger amount, that will be a (kB-)large transaction.

Yes, every address (=public key id) has its own private key. So it would compromise what is sent to the vanity address.

Yes. It's not recommended but you can use older versions (down to 0.6.x or so) and they can still sync the entire chain.

Based on your authority, deepceleron, I simply can't wait until all the new features of Litecoin will be included in Bitcoin, since Namecoin is the only one with a new feature that WON'T be. /sarcasm

Perhaps you are reading the intention of the sentence incorrectly; the unique feature of Namecoin that "won't be included" in Bitcoin is the storage of user data for domain names and other identity (http://explorer.bit.pe/n/74491) or yet-imagined purposes. Storing arbitrary data is outside of the scope of Bitcoin, which is a network for the bitcoin currency; such features won't be added to it.

I am new to bitcoin.Which program is best for newbies? Bitcoin-qt or multibit

I second that question, and is multibit secure?
does anyone know where i can download a bitcoin blockchain and how i add it to the wallet? Ive spent ages trying to sync the bitcoin wallet but it doesnt seem to do anything, so have gone with multibit.

I download both programs. Multibit is good for newbies, bitcoin-qt is keep synchronizing

Insert Quote
I download both programs. Multibit is good for newbies, bitcoin-qt is keep synchronizing


do you mean just be patient?

multibit

bitcoin-qt is a full node that you can run to support the network, not for newbies that just want a wallet

I have had to reload the blockchain 3 times this year!
Anybody know when the QT version that does not require you to download the chain will be available? ???

Either it will download blockchain or it will not be QT.

Get electrum

Electrum != QT
Like I said.

So the answer should be: "Such version will never be available. (If it is it will not be QT anymore.)"

there is no such a version of QT..

Thank you very much to tell me about the release of new version. I will definitely try the new version as I was already facing few problems. I hope this update will finally solve the bugs that were becoming a headache for me. Please keep on sharing such news with me, I shall appreciate it

For newbies, I'd recommend electrum (https://electrum.org/download.html) as an SPV client.
Once you become familiar with bitcoin, you would want to be a full node and take the time to download the whole blockchain with bitcoin-qt and strong password for wallet encryption.
Avoid windows.

Electrum is easy to use but it needs centralized servers. It is not a pure P2P client.

Bitcoin-Qt is pure P2P. Multibit is pure P2P.

i'll wait for the 64-bit version.

SPV is specified in Satoshi's original paper for thin clients; A thin client (multibit or electrum) is NOT P2P because it needs full nodes to function. Anybody can run a full node electrum server. There is no "central" electrum server: you can chose the one you want to connect to.

Multibit IS pure P2P. Schildbach's Android wallet is also pure P2P. They implement the SPV concept of Satoshi. None of the two implementations are are used in validating nodes, but they are pure P2P.

https://plus.google.com/+MikeHearn/posts/hzySWGzHAcJ (https://plus.google.com/+MikeHearn/posts/hzySWGzHAcJ)

Electrum is not P2P and it does not implement Satoshi's SPV concept.

Bitcoin-Qt is P2P and their nodes fully validate transactions.

Good news... thanks a lot!

Thats being dealt with via the SPV protocol, already implemented in  MultiBit client.

Only namecoin attempting to add value?? you need to do your homework before making that kind of statement. I'm no fan of the me2 coins but there are some excellent innovations happening in the alt space.

Who are "they"? Do you want me to beat them up? Bitcoin is neither suitable nor designed for micropayments, it never was, and never will be. Anyone who says otherwise deserves to be punched in the face.

EDIT: Typo

There would be no opposition to adding a port option in the UI options.

Bandwidth limiting on the other hand is currently stalled until parallel block download is implemented. Currently a single slowed down peer can have too much impact.

Nevertheless you may be indeed able to limit the bandwidth on the OS level, a sample QoS script for Linux is even included in contrib/qos.

Anyone know when will bitcoind version 0.8.7 be release?
hopefully by this month!

I think it's going to 0.9 to help address the transaction malleability, dust spam issues, fees reduction etc.

My estimate for 0.9 is March
RC2 is already out
http://sourceforge.net/projects/bitcoin/files/Bitcoin/bitcoin-0.9.0/test/

https://bitcointalk.org/index.php?topic=495683.msg5460062#msg5460062

What security features does this upgrade incorporate, or are these wallets still basically candy for CCSM's to freely take people's coin as they please?

I am having some serious problems with Bitcoin-QT on openSUSE sending bitcoins to another wallet.

I am using:

Bitcoin v0.8.6.0-g03a7d67-beta
QT v4.8.5

This post explains the issue and has all the screen shots:

https://bitcointalk.org/index.php?topic=516059.0

Thanks,

so please do not post MALWARED link in your comment :)

Why anyone would like to use Bitcoin-qt over Multibit i don't get it.

If Bitcoin didn't exist, Bitcoin wouldn't exist. It is the single piece of software powering the network, miners run Bitcoin, merchants run Bitcoin, and Multibit connects to someone running Bitcoin.

That is like asking why anyone would prefer hamburgers over mustard.

Because I am running a P2Pool node which uses bitcoind/bitcon-qt

Cause I don't trust any nodes on the network.

Very simple: to support the network.
If no one was running bitcoind/-qt, there would be no network and no bitcoin.

I like this new version , but anyway i prefer MultiBit

Well this is kind interesting :)

But sometimes you need to rely on a node...
:) it makes things easier when using Android wallet..

That's the point! no more to say

Support the network!

True. but just want to add that IMO - without qt we could find another ways to keep lines up.
But it is not needed to think about.

I think qt is great wallet and I do not know why to not use that :)

I prefere qt more than anyother.
But I am using android wallet for most of transactions because I have it always near to me.

I run a few systems with bitcoin-qt (now Bitcoin Core) to support the network.
I am a bit less keen on the v0.9 client with the x.509 centralisation.
I look forward to a fork, hostile or not, that uses a distributed certificate keyserver system for those odd ducks that want additionally authenticated sources and destinations beyond the EC.
This weird centralisation in bitcoin core is ill considered and presents an external risk which is unnecessary.

I get that it is an answer to the coinvalidation seekers, but it is a poorly designed answer.

Please pass me a fork. 

Until then, not upgrading even though the 0.8.6 client doesn't resolve the malliated issues and I have wallets that don't know how many coins they have in them because they have 0 confirmation spends in them that are counted against the total due to the malliation spam in February, so my wallets would have more spendable coins if I upgrade, not worth it.

This article by Mike Hearn has helped me understand the X.509 solution for Bitcoin. I hope it helps you too.

https://medium.com/p/b64cf5912aa7 (https://medium.com/p/b64cf5912aa7)

X509 is not centralized, it is hierarchichal. I feel it is the best approach for Bitcoin to succeed.

First of all let me say I'm a noob.
I still use bitcoin-qt latest version.
Do I have to upgrade it to bitcoin core? And, above all, Is it an upgrading or they are two different things?

any help is appreciated, thx in advance

As far as I know bitcoinqt was renamed to Bitcoin core after version 0.9

Thx for your reply.
So do you think I just have to run bitcoincore  setup oon my pc and it will replace old QT version?

thx again for your help

Here is your answer: https://bitcoin.org/bin/0.9.0/README.txt (https://bitcoin.org/bin/0.9.0/README.txt)

Quoting:

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), uninstall all
earlier versions of Bitcoin, 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
0.9.0 your blockchain files will be re-indexed, which will take anywhere from
30 minutes to several hours, depending on the speed of your machine.

On Windows, do not forget to uninstall all earlier versions of the Bitcoin
client first, especially if you are switching to the 64-bit version.

Ty shawshank,
it is what I was looking for.

It is less a lack of understanding (I've run x.509 CA and RA departments for Telcos) and more a fundamental disagreement that the best they can do on this today is good enough or necessary enough.
Perhaps I am just more patient.

I just updated Bitcoin-QT from .8 (I think) to .8.5 just last week. I waited because I have a concern that it's possible that one day some release could be corrupted (intentionally or not), and jeopardize the currency. I read about this .8.6 update and it says it fixes a bug, and encourages updating asap... which is something like it might say if someone were intentionally up to shenanigans, no?

That's my point here.. Is it always best to upgrade asap for currency integrity purposes only? I acknowledge I'm pretty ignorant of technical stuff, so I'm asking, is there any reason for concern, or no? Hypothetically, could this ever be an issue?