Sometimes new people are confused by how a revision "range" works,
in that it is not a random collection of commits but a set of
commits that are all connected to each other, and most Git commands
work on a single such "range".
Give an example to clarify it.
Signed-off-by: Junio C Hamano <gitster@xxxxxxxxx>
---
* So, here it is in a proper patch form, with an extended
description and illustration.
Documentation/revisions.txt | 23 +++++++++++++++++++++++
1 file changed, 23 insertions(+)
diff --git a/Documentation/revisions.txt b/Documentation/revisions.txt
index d9169c062e..f5f17b65a1 100644
--- a/Documentation/revisions.txt
+++ b/Documentation/revisions.txt
@@ -260,6 +260,9 @@ any of the given commits.
A commit's reachable set is the commit itself and the commits in
its ancestry chain.
+There are several notations to specify a set of connected commits
+(called a "revision range"), illustrated below.
+
Commit Exclusions
~~~~~~~~~~~~~~~~~
@@ -294,6 +297,26 @@ is a shorthand for 'HEAD..origin' and asks "What did the origin do since
I forked from them?" Note that '..' would mean 'HEAD..HEAD' which is an
empty range that is both reachable and unreachable from HEAD.
+Commands that are specifically designed to take two distinct ranges
+(e.g. "git range-diff R1 R2" to compare two ranges) do exist, but
+they are exceptions. Unless otherwise noted, all "git" commands
+that operate on a set of commits work on a single revision range.
+In other words, writing two "two-dot range notation" next to each
+other, e.g.
+
+ $ git log A..B C..D
+
+does *not* specify two revision ranges for most commands. Instead
+it will name a single connected set of commits, i.e. those that are
+reachable from either B or D but are reachable from neither A or C.
+In a linear history like this:
+
+ ---A---B---o---o---C---D
+
+because A and B are reachable from C, the revision range specified
+by these two dotted ranges is a single commit D.
+
+
Other <rev>{caret} Parent Shorthand Notations
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Three other shorthands exist, particularly useful for merge commits,
--
2.32.0-rc0-111-g32b9632252
