Re: [PATCH 2/5] add object-cache infrastructure

On Tue, Jul 12, 2011 at 5:07 PM, Clemens Buchacher [off-list ref] wrote:
[snip]

Now, one might argue that this is a corner case. But it's actually
very common. In the example, the patch-id changes because of an
extra change in a different text area. That is indeed unlikely.
However, the same problem will occur in a much more common case.
Let's say we have a patch with 10 hunks. The patch is applied
upstream, with only one difference in one of the hunks.
Subsequently, text areas affected by any of the other hunks change
upstream. When the original patch is rebased on top of that, it
will conflict with the one hunk that was changed in the upstream
version of that patch. And that's ok. Git should not decide which
version is correct. But in addition to that conflict there will
also be conflicts for all the other hunks, which the upstream patch
did _not_ modify. And all of those conflicts will look like
reverts.

I believe that is the main reason why rebase is so painful all the
time.

Clemens, that's a great description of the problem.  I've run into
this several times, and it is really confusing.  I've spent
considerable time tracking down the real conflict... only to find the
real issue was in something non-related and easily resolved.  IMHO, I
agree with you Clemens: this has been my major source of pain.

-John