Re: [PATCH 0/3] Teach Git about the patience diff algorithm

[Sam Vilain <sam@vilain.net>]

Linus Torvalds wrote:
> On Thu, 8 Jan 2009, Sam Vilain wrote:
>   
>> Whatever happens, the current deterministic diff algorithm needs to stay
>> for generating patch-id's... those really can't be allowed to change.
>>     
>
> Sure they can.
>
> We never cache patch-id's over a long time. And we _have_ changed xdiff to 
> modify the output of the patches before, quite regardless of any patience 
> issues: see commit 9b28d55401a529ff08c709f42f66e765c93b0a20, which 
> admittedly doesn't affect any _normal_ diffs, but can generate subtly 
> different results for some cases.
>   

There's at least one person who thinks that they should be deterministic 
enough to be able to be placed in commit messages;

http://article.gmane.org/gmane.comp.version-control.git/95671

Now of course the git cherry-pick feature to add the old patch ID to the 
commit message isn't written yet; but unless there was a fall-back mode 
to produce a "stable" patch ID, these breadcrumbs would become (even 
more) worthless.

Sam