Sergey Organov <sorganov@xxxxxxxxx> writes: > This option provides a shortcut to request diff with respect to first > parent for any kind of commit, universally. It's implemented as pure > synonym for "--diff-merges=first-parent --patch". That explains what the patch does, but it does not tell us why it is useful [*]. > NOTE: originally proposed as '-d', and renamed to '--dd' due to Junio > request to keep "short-and-sweet" '-d' reserved for other uses. The note is not grammatical, and more importantly, readers of "git log" 6 months down the road would not care. I'd rather not see it in the proposed log message. It is suitable material to place after the three-dash line, or in the cover letter for the iteration. > diff --git a/diff-merges.c b/diff-merges.c > index ec97616db1df..45507588a279 100644 > --- a/diff-merges.c > +++ b/diff-merges.c > @@ -131,6 +131,9 @@ int diff_merges_parse_opts(struct rev_info *revs, const char **argv) > } else if (!strcmp(arg, "--cc")) { > set_dense_combined(revs); > revs->merges_imply_patch = 1; > + } else if (!strcmp(arg, "--dd")) { > + set_first_parent(revs); > + revs->merges_imply_patch = 1; Quite straight-forward as expected. I do not think "--dd" clicks for many people as "first parent diffs all over", though. > } else if (!strcmp(arg, "--remerge-diff")) { > set_remerge_diff(revs); > revs->merges_imply_patch = 1; > diff --git a/t/t4013-diff-various.sh b/t/t4013-diff-various.sh > index 5de1d190759f..4b474808311e 100755 > --- a/t/t4013-diff-various.sh > +++ b/t/t4013-diff-various.sh > @@ -473,6 +473,14 @@ test_expect_success 'log --diff-merges=on matches --diff-merges=separate' ' > test_cmp expected actual > ' > > +test_expect_success 'log --dd matches --diff-merges=1 -p' ' > + git log --diff-merges=1 -p master >result && > + process_diffs result >expected && > + git log --dd master >result && > + process_diffs result >actual && > + test_cmp expected actual > +' > + > test_expect_success 'deny wrong log.diffMerges config' ' > test_config log.diffMerges wrong-value && > test_expect_code 128 git log Looking good. Thanks. [Footnote] * As I said elsewhere, I do not think it is a good idea to encourage users' to adopt a screwed-up worldview in which first parent is special but not special, and does the wrong thing for reverse merges. If the option were short-hand for "--first-parent -p", at least I would be more sympathetic.