From: Jon Seymour Date: Thu, 20 May 2010 23:05:46 GMT Subject: Re: Need to change old commit (and regenerate tree) Message-ID: In-Reply-To: On Fri, May 21, 2010 at 8:09 AM, Andreas Schwab wrote: > Antriksh Pany writes: > >> Instead of (what I initially expected): >> >> A--------o--------o--------o--------o(old B)--------o--------o--------o(old C) >> >> A2--------o--------o--------o--------B--------o--------o--------C >> >> >> So what I am missing here? Aren't the new commits B~1, B~2, B~3 >> identical to C~4, C~5, C~6 (respectively) in all ways so as to have >> gotten them the same SHA1 and hence appear as what I expected them to >> appear? > > No, they have a different commit time, which is also part of the hash. > Of course, even if the commit time was forged to be the same, the parent of B~3 is different to the parent of C~6 and since the parent is also contributes bits to the respective hashes, B~3 will necessarily (unlikely hash collisions excepted!) have a different hash to C~6 jon.