Re: [PATCH] format-patch: allow a non-integral version numbers

On 2021-02-25 10:13:24-0800, Junio C Hamano [off-list ref] wrote:

"ZheNing Hu via GitGitGadget" [off-list ref] writes:

quoted

From: ZheNing Hu <redacted>

Usually we can only use `format-patch -v<n>` to generate integral
version numbers patches, but if we can provide `format-patch` with
non-integer versions numbers of patches, this may help us to send patches
such as "v1.1" versions sometimes.

I am not in principle opposed to support a fractional version number
that comes after an integral one, which allows users to signal that
it is a minor correction that does not deserve a full version bump.

I'm late into the party, but this rational sounds greate to me.

If we were to do this, I would probably suggest a preliminary patch
that refactors the hardcoded "reroll_count - 1" out of diff_title()
so that the helper takes two "reroll count strings", i.e. reroll
count for this round, and the previous round, as two separate
parameters.  Teach the caller to pass "reroll_count - 1" for the new
parameter in this preliminary step.

However, if it's only a minor correction to the major version,
I _think_ it makes better sense to compare with the major version
instead of comparing with another minor version.
When a reviewer reviews v3.5, they can just compare to v3.
In a hypothetical world, when another reviewer jump in and a major
change required, v4 reroll also compare with v3.

In other words, we will have something likes:

 - v3   vs v2
 - v3.1 vs v3
 - v3.2 vs v3
 ....
 - v4   vs v3

The good side of this approach is: the logic to choose previous
version is simple.

The downside of this approach is: reviewers need to re-read the
changes in v3.1 v3.2, etc... However, we can reasonably expect those
changes are small enough, they're minor changes after all.

And they will need to re-read all the change if the major verison was
increased.

-- 
Danh