On 25 Apr 22 ◦ 04:09, Eric Sunshine wrote: > On Sun, Apr 24, 2022 at 9:00 AM FanJun Kong <bh1scw@xxxxxxxxx> wrote: > > First, I created two commits to a demo project. > > > > when I use command: > > git format-patch --cover-letter -1 > > [...] > > FanJun Kong (1): > > First commit. > > 1.c | 4 ++++ > > 1 file changed, 4 insertions(+) > > > > ok, you can see the cover letter has diffstat, just above "--". > > > > git format-patch --cover-letter -2 > > [...] > > FanJun Kong (2): > > First commit. > > Second commit. > > > > Comparing with last command, I just want to get 2 patches, > > but this time the diffstat is missing. > > > > I am not sure if this is a bug or I miss some options. > > This is expected behavior according to this code in > make_cover_letter() in builtin/log.c: > > /* We can only do diffstat with a unique reference point */ > if (origin) > show_diffstat(rev, origin, head); > > The problem is that when you format both patches of a two-commit > repository, `origin` is NULL because there is no commit preceding the > initial commit; the initial commit is the root of the history. Thus, > there is nothing prior to the first patch against which to create a > diffstat. > Very clear explanation, yeah~ > I have not investigated, but it may be possible to teach > show_diffstat() how to generate a diffstat against the "emptiness" > preceding the initial commit, but nobody has done so yet. Perhaps this > would be a good project for someone interested in contributing to the > project (or perhaps not -- as mentioned, I haven't investigated how > hard this would be). >From my point of view, it is a bug, but it doesn't affect too much. I agree with your suggestion, this is a nice chance to learn how to submit patches to upstream.
