git-rev-list.txt: move description to separate file

A following commit will reuse the description of the `git rev-list`
command in the `git log` manpage.

Move this description to a separate file.

Signed-off-by: Philippe Blain <levraiphilippeblain@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 38 insertions, 0 deletions

diff --git a/Documentation/rev-list-description.txt b/Documentation/rev-list-description.txt
new file mode 100644
index 0000000000..14d78b91aa
--- /dev/null
+++ b/Documentation/rev-list-description.txt
@@ -0,0 +1,38 @@
+List commits that are reachable by following the `parent` links from the
+given commit(s), but exclude commits that are reachable from the one(s)
+given with a '{caret}' in front of them.  The output is given in reverse
+chronological order by default.
+
+You can think of this as a set operation. Commits reachable from any of
+the commits given on the command line form a set, and then commits reachable
+from any of the ones given with '{caret}' in front are subtracted from that
+set.  The remaining commits are what comes out in the command's output.
+Various other options and paths parameters can be used to further limit the
+result.
+
+Thus, the following command:
+
+-----------------------------------------------------------------------
+$ git rev-list foo bar ^baz
+-----------------------------------------------------------------------
+
+means "list all the commits which are reachable from 'foo' or 'bar', but
+not from 'baz'".
+
+A special notation "'<commit1>'..'<commit2>'" can be used as a
+short-hand for "^'<commit1>' '<commit2>'". For example, either of
+the following may be used interchangeably:
+
+-----------------------------------------------------------------------
+$ git rev-list origin..HEAD
+$ git rev-list HEAD ^origin
+-----------------------------------------------------------------------
+
+Another special notation is "'<commit1>'...'<commit2>'" which is useful
+for merges.  The resulting set of commits is the symmetric difference
+between the two operands.  The following two commands are equivalent:
+
+-----------------------------------------------------------------------
+$ git rev-list A B --not $(git merge-base --all A B)
+$ git rev-list A...B
+-----------------------------------------------------------------------