From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from sog-mx-4.v43.ch3.sourceforge.com ([172.29.43.194] helo=mx.sourceforge.net) by sfs-ml-2.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1X6Vxl-0005qi-VK for bitcoin-development@lists.sourceforge.net; Mon, 14 Jul 2014 02:25:58 +0000 Received-SPF: pass (sog-mx-4.v43.ch3.sourceforge.com: domain of gmail.com designates 209.85.219.50 as permitted sender) client-ip=209.85.219.50; envelope-from=voisine@gmail.com; helo=mail-oa0-f50.google.com; Received: from mail-oa0-f50.google.com ([209.85.219.50]) by sog-mx-4.v43.ch3.sourceforge.com with esmtps (TLSv1:RC4-SHA:128) (Exim 4.76) id 1X6Vxk-0008BV-RX for bitcoin-development@lists.sourceforge.net; Mon, 14 Jul 2014 02:25:57 +0000 Received: by mail-oa0-f50.google.com with SMTP id g18so3559674oah.23 for ; Sun, 13 Jul 2014 19:25:51 -0700 (PDT) MIME-Version: 1.0 X-Received: by 10.182.19.196 with SMTP id h4mr15100293obe.20.1405304751206; Sun, 13 Jul 2014 19:25:51 -0700 (PDT) Received: by 10.60.169.109 with HTTP; Sun, 13 Jul 2014 19:25:51 -0700 (PDT) In-Reply-To: <35E6FF51-F9C4-4973-8489-B364E7C27C14@ricmoo.com> References: <35E6FF51-F9C4-4973-8489-B364E7C27C14@ricmoo.com> Date: Sun, 13 Jul 2014 19:25:51 -0700 Message-ID: From: Aaron Voisine To: Richard Moore Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable X-Spam-Score: -1.6 (-) X-Spam-Report: Spam Filtering performed by mx.sourceforge.net. See http://spamassassin.org/tag/ for more details. -1.5 SPF_CHECK_PASS SPF reports sender host as permitted sender for sender-domain 0.0 FREEMAIL_FROM Sender email is commonly abused enduser mail provider (voisine[at]gmail.com) -0.0 SPF_PASS SPF: sender matches SPF record -0.1 DKIM_VALID_AU Message has a valid DKIM or DK signature from author's domain 0.1 DKIM_SIGNED Message has a DKIM or DK signature, not necessarily valid -0.1 DKIM_VALID Message has at least one valid DKIM or DK signature X-Headers-End: 1X6Vxk-0008BV-RX Cc: Bitcoin Dev Subject: Re: [Bitcoin-development] Self-dependency transaction question... X-BeenThere: bitcoin-development@lists.sourceforge.net X-Mailman-Version: 2.1.9 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 14 Jul 2014 02:25:58 -0000 I believe tx have to be ordered sequentially within a block. Also since a tx is referenced by it's hash, it's practically impossible to make a self referential tx. Aaron Voisine breadwallet.com On Sun, Jul 13, 2014 at 4:32 PM, Richard Moore wrote: > Hey all, > > I'm working on the UTXO database for my Python implementation of bitcoind > and have found a situation I did not realize was valid, but since it seem= s > to be, had a quick question. > > If you look at block #546 the 4th transaction's first input uses its own > block's 3rd transaction as an input. > https://blockchain.info/block/000000005a4ded781e667e06ceefafb71410b511fe0= d5adc3e5a27ecbec34ae6 > > My question is, would the other way be valid, that is, could the 3rd > transaction of a block, use the 4th transaction from the same block as an > input? Or are transactions processed strictly top to bottom? > > Thanks, > RicMoo > > P.S. If it is valid, another question; what would happen if a transaction > was self-referencing? I realize it would be very difficult to find one, b= ut > if I could find a transaction X whose input was X and had an output Y, wo= uld > Y be a new valid utxo, without being a generation transaction input? > > .=C2=B7=C2=B4=C2=AF`=C2=B7.=C2=B8=C2=B8.=C2=B7=C2=B4=C2=AF`=C2=B7.=C2=B8= =C2=B8.=C2=B7=C2=B4=C2=AF`=C2=B7.=C2=B8=C2=B8.=C2=B7=C2=B4=C2=AF`=C2=B7.=C2= =B8=C2=B8.=C2=B7=C2=B4=C2=AF`=C2=B7.=C2=B8><(((=C2=BA> > > Richard Moore ~ Founder > Genetic Mistakes Software inc. > phone: (778) 882-6125 > email: ricmoo@geneticmistakes.com > www: http://GeneticMistakes.com > > > -------------------------------------------------------------------------= ----- > Want fast and easy access to all the code in your enterprise? Index and > search up to 200,000 lines of code with a free copy of Black Duck® > Code Sight™ - the same software that powers the world's largest code > search on Ohloh, the Black Duck Open Hub! Try it now. > http://p.sf.net/sfu/bds > _______________________________________________ > Bitcoin-development mailing list > Bitcoin-development@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/bitcoin-development >