t4013: test that "-m" alone has no effect in "git log"

This is to notice current behavior that we are going to change when we
start to imply "-p" by "-m".

Signed-off-by: Sergey Organov <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: sorganov

t/t4013-diff-various.sh

@@ -452,6 +452,14 @@ diff-tree --stat --compact-summary initial mode
 diff-tree -R --stat --compact-summary initial mode
 EOF
 
+test_expect_success 'log -m matches pure log' '
+	git log master >result &&
+	process_diffs result >expected &&
+	git log -m >result &&
+	process_diffs result >actual &&
+	test_cmp expected actual
+'
+
 test_expect_success 'log --diff-merges=on matches --diff-merges=separate' '
 	git log -p --diff-merges=separate master >result &&
 	process_diffs result >expected &&