Git commit hash clash prevention

Hi folks,

the other day during a workshop on Git, one of the attendants asked
about the scenario when two developers, Jane and David, both working
on the same project, both create a commit and the two just so happen
to have the same SHA-1. I realise that the likelihood of this
happening is about as high as the chance of <insert witty joke
here>, but it *is* possible, isn't it? Even though this is thus
somewhat academic, I am still very curious about it.

What happens when David now pulls from Jane? How does Git deal with
this?

I imagine it'll be able to distinguish the two commits based on
metadata, but won't the DAG get corrupted?

Cheers,

-- 
martin | http://madduck.net/ | http://two.sentenc.es/
 
"and no one sings me lullabies,
 and no one makes me close my eyes,
 and so i throw the windows wide,
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                                                   -- pink floyd, 1971
 
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