Hi Junio, On Fri, 22 Jan 2021, Junio C Hamano wrote: > Johannes Schindelin <Johannes.Schindelin@xxxxxx> writes: > > >> > +- `<rev1>...<rev2>`. This resembles the symmetric ranges mentioned in > >> > + the `SPECIFYING RANGES` section of linkgit:gitrevisions[7], and is > >> > + equivalent to `<base>..<rev1> <base>..<rev2>` where `<base>` is the > >> > + merge base as obtained via `git merge-base <rev1> <rev2>`. > > The above paragraph says A...B is turned into $(git merge-base A > B)..A and $(git merge-base A B)..B, but I wonder if we should be > rewriting it into A..B and B..A instead; that would make it > unnecessary to explain what should happen when there are more than > one merge bases. You know what? I lied. The code already does what you suggested. Look [here](https://github.com/git/git/blob/v2.30.0/builtin/range-diff.c#L59-L77): [...] } else if (argc == 1) { const char *b = strstr(argv[0], "..."), *a = argv[0]; int a_len; if (!b) { error(_("single arg format must be symmetric range")); usage_with_options(builtin_range_diff_usage, options); } a_len = (int)(b - a); if (!a_len) { a = "HEAD"; a_len = strlen(a); } b += 3; if (!*b) b = "HEAD"; strbuf_addf(&range1, "%s..%.*s", b, a_len, a); strbuf_addf(&range2, "%.*s..%s", a_len, a, b); [...] > >> Does this merely resemble? Isn't it exactly what a symmetric range is? > > > > No, it is not exactly what a symmetric range is because `range-diff` > > treats both arms of the symmetric range independently, as two distinct > > non-symmetric ranges. > > This however is an end-user documentation, isn't it? Yes, and the end user is talking about _two_ commit ranges in the context of `git range-diff`, and about _one_ commit range in the context of `git log`. So I still think that it really just only resembles the symmetric range. It is fundamentally as different from it as the number 2 is different from the number 1. Ciao, Dscho
