Re: [PATCH 3/3] range-diff(docs): explain how to specify commit ranges

Hi Junio,

On Thu, 21 Jan 2021, Junio C Hamano wrote:

"Johannes Schindelin via GitGitGadget" [off-list ref]
writes:

quoted

From: Johannes Schindelin <redacted>

There are three forms, depending whether the user specifies one, two or
three non-option arguments. We've never actually explained how this
works in the manual, so let's explain it.

Signed-off-by: Johannes Schindelin <redacted>
---
 Documentation/git-range-diff.txt | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/Documentation/git-range-diff.txt b/Documentation/git-range-diff.txt
index 9701c1e5fdd..76359baf26d 100644
--- a/Documentation/git-range-diff.txt
+++ b/Documentation/git-range-diff.txt

@@ -28,6 +28,19 @@ Finally, the list of matching commits is shown in the order of the
 second commit range, with unmatched commits being inserted just after
 all of their ancestors have been shown.

+There are three ways to specify the commit ranges:
+
+- `<range1> <range2>`: Either commit range can be of the form
+  `<base>..<rev>`, `<rev>^!` or `<rev>^-<n>`. See `SPECIFYING RANGES`
+  in linkgit:gitrevisions[7] for more details.

Good.

quoted

+- `<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>`.

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.

quoted

+- `<base> <rev1> <rev2>`: This is equivalent to `<base>..<rev1>
+  <base>..<rev2>`.

Nice to see this documented.

Yes. I was rather surprised that I had overlooked that in my original
submission of the `range-diff` command.

Ciao,
Dscho