--- a/tests/test-amend.t Mon Jan 07 21:39:35 2019 +0900
+++ b/tests/test-amend.t Mon Jan 07 21:43:06 2019 +0900
@@ -438,3 +438,25 @@
user: foobar
date: Thu Jan 01 00:01:00 1998 +0000
summary: commit 1
+
+Unlike rewrite.update-timestamp, -D/--currentdate always updates the timestamp
+
+ $ hg amend -D
+ $ hg log --limit 1
+ user: foobar
+ date: Thu Jan 01 00:00:04 1970 +0000
+ summary: commit 1
+
+ $ hg amend -D --config rewrite.update-timestamp=True
+ $ hg log --limit 1
+ user: foobar
+ date: Thu Jan 01 00:00:05 1970 +0000
+ summary: commit 1
+
+Bad combination of date options:
+
+ $ hg amend -D --date '0 0'
+ abort: --date and --currentdate are mutually exclusive
+ [255]
+
+ $ cd ..