Re: Does content provenance matter?

--- On Mon, 5/7/12, Thomas Rast <trast@student.ethz.ch> wrote:

What's the difference between the following series of
commits?

  Foo
  Bar
  Revert Bar

and

  Foo

You claim that they're the same, because the tree state
after each is
the same.  But I learned that Bar was broken, and
recorded it for all to see.

No, I don't claim they're the same. Different commits have different timestamps (and different commit messages, but that's not useful for automatic searching to find which commits are derived from which others). Consider if "Revert Bar" and "Bar" didn't point to their parents; could you still deduce from them that Bar was broken? Yes--on the basis of the commit timestamps (which shows their temporal order) and the contents of the trees which the commits point to (which shows that Revert Bar undoes a change made in Bar).