On Sat, 16 Aug 2025 at 14:58:56 -0700, Russ Allbery wrote:
Right, this is what I was talking about with incremental reviews. GitHub
now supports showing you only the differences since the last time you
reviewed it.
For what it's worth, Gitlab can also show you the differences between
arbitrary revisions of a merge request. For example in
https://salsa.debian.org/ci-team/autopkgtest/-/merge_requests/583 you
can see (behind the "Compare with previous version" link) that I applied
some lint fixes between v1 and v2.
Similarly in
https://salsa.debian.org/ci-team/autopkgtest/-/merge_requests/583/diffs,
the toolbar that says "Compare [master] and [latest version]" would let
you compare any pair of versions of the MR (for this particular MR there
are not many to choose between).
Viewing commit-by-commit doesn't have that feature available, but that's
probably unavoidable, because...
I agree that it's not quite as good as Gerrit at showing you deltas
between arbitrary revisions of the patch
... Github, Gitlab, and the git data model in general don't really have
any concept of what is "a different revision of the same patch" - the
only information they have is an earlier version of the pull/merge
request (a base commit + a patch series), and a later version (base
commit + patch series again). Gerrit can identify that you think a
commit is "the same" by it keeping a previously-used Change-ID, but
without enforcing that information being present, Github and Gitlab
can't know that you consider two commits with very similar commit
messages or very similar diffs to be "the same thing".
In practice I usually prefer to review commit-by-commit for a first pass
or when there have been significant changes, or "Compare with previous
version" for a quick check that previous review feedback has been taken
into account.
smcv
