rev-list: documentation and test for --cherry-mark

Signed-off-by: Michael J Gruber <git@drmicha.warpmail.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/git-rev-list.txt

@@ -33,6 +33,7 @@ SYNOPSIS
 	     [ \--left-right ]
 	     [ \--left-only ]
 	     [ \--right-only ]
+	     [ \--cherry-mark ]
 	     [ \--cherry-pick ]
 	     [ \--encoding[=<encoding>] ]
 	     [ \--(author|committer|grep)=<pattern> ]

Documentation/rev-list-options.txt

@@ -305,6 +305,11 @@ ifdef::git-rev-list[]
 	to /dev/null as the output does not have to be formatted.
 endif::git-rev-list[]
 
+--cherry-mark::
+
+	Like `--cherry-pick` (see below) but mark equivalent commits
+	with `=` rather than omitting them, and inequivalent ones with `+`.
+
 --cherry-pick::
 
 	Omit any commit that introduces the same change as

t/t6007-rev-list-cherry-pick-file.sh

@@ -99,6 +99,34 @@ test_expect_success '--cherry-pick bar does not come up empty (II)' '
 	test_cmp actual.named expect
 '
 
+cat >expect <<EOF
++tags/F
+=tags/D
++tags/E
+=tags/C
+EOF
+
+test_expect_success '--cherry-mark' '
+	git rev-list --cherry-mark F...E -- bar > actual &&
+	git name-rev --stdin --name-only --refs="*tags/*" \
+		< actual > actual.named &&
+	test_cmp actual.named expect
+'
+
+cat >expect <<EOF
+<tags/F
+=tags/D
+>tags/E
+=tags/C
+EOF
+
+test_expect_success '--cherry-mark --left-right' '
+	git rev-list --cherry-mark --left-right F...E -- bar > actual &&
+	git name-rev --stdin --name-only --refs="*tags/*" \
+		< actual > actual.named &&
+	test_cmp actual.named expect
+'
+
 cat >expect <<EOF
 tags/E
 EOF