From: Nguyen Thai Ngoc Duy Date: Wed, 18 Aug 2010 03:17:52 GMT Subject: Re: [RFC/PATCH 1/2] commit: add parse_commit_repl() to replace commits at parsing time Message-ID: In-Reply-To: <7vbp91aqfk.fsf@alter.siamese.dyndns.org> On Wed, Aug 18, 2010 at 7:18 AM, Junio C Hamano wrote: > Christian Couder writes: > >> The function parse_commit() is not safe regarding replaced commits >> because it uses the buffer of the replacement commit but the object >> part of the commit struct stay the same. Especially the sha1 is not >> changed so it doesn't match the content of the commit. > > This all sounds backwards to me, if I am reading the discussion correctly. > > If a replace record says commit 0123 is replaced by commit 4567 (iow, 0123 > was a mistake, and pretend that its content is what is recorded in 4567), > and when we are honoring the replace records (iow, we are not fsck), > shouldn't read_sha1("0123") give us a piece of memory that stores what is > recorded in 4567, parse_object("0123") return a struct commit whose buffer > points at a block of memory that has what is recorded in 4567 _while_ its > object.sha1[] say "0123"? 1. parse_object() as it is now would return object.sha1[] = "4567". 2. lookup_commit(), then parse_commit() would return object.sha1[] = "0123". > What problem are you trying to solve? Inconsistency in replacing objects. I have no comments whether #1 or #2 is expected behavior. But at least it should stick to one behavior only. -- Duy