On Mon, Sep 23, 2024, at 21:05, Eric Sunshine wrote:
> On Mon, Sep 23, 2024 at 2:44 PM Kristoffer Haugsbakk
> <kristofferhaugsbakk@xxxxxxxxxxxx> wrote:
>> On Mon, Sep 23, 2024, at 19:51, Eric Sunshine wrote:
>> > Depending upon how dramatically the patch series changes from one
>> > version to the next, the range-diff may end up being unreadable
>> > gobbledygook, in which case you may instead want to include an
>> > interdiff ("git format-patch --interdiff").
>>
>> What’s the benefit of interdiff in that case? Neither
>> git-format-patch(1) nor git-range-diff(1) seems to discuss what the
>> differences between these two are.
>
> An interdiff is just a plain diff. If you have branch (or tag) "v1"
> which is the original version of a patch series, and "v2" which is the
> reroll of the series, then interdiff is simply:
>
> git diff v1 v2
>
> Thus, it shows the difference between the final state of the code at
> v1 and the state at v2. Interdiffs are easy to read because they are
> just diffs. However, because they are only showing differences in file
> content, they don't show changes to commit messages or new or removed
> or reordered patches in a series.
>
> A range-diff is a diff-of-diffs. It is very, very roughly similar to this:
>
> git format-patch -o v1-patches <common-base>..v1
> git format-patch -o v2-patches <common-base>..v2
> some-diff-dir-command v1-patches v2-patches
>
> It shows the diff of the patches themselves, including changes to
> commit messages and changes to changes, as well as inserted and
> removed and reordered patches.
>
> Range-diffs tend to be a good deal more difficult to read (at least at
> first) but help show the evolution of the _patch series_ itself
> between versions, whereas interdiffs show only the evolution of the
> _code_ between versions. As a reviewer, if you're primarily interested
> in how the code evolved, then interdiffs are much more easily
> digested, but most reviewers are also interested in the holistic
> aspects of a patch series for which range-diffs are more helpful. I
> periodically include both range-diff and interdiffs in my rerolls.
Thanks for that. I love when a good range-diff falls out of a
reroll—and I love the tool—but of course that can’t be expected out of
every reroll.
--
Kristoffer Haugsbakk
