Crypt the text in the undo file if the file itself is crypted.
diff --git a/src/testdir/test72.ok b/src/testdir/test72.ok
index 66e7250..44210c9 100644
--- a/src/testdir/test72.ok
+++ b/src/testdir/test72.ok
@@ -7,3 +7,11 @@
 eight
 nine
 ten
+monday
+wednesday
+thursday
+friday
+bar apr
+apr
+foo mar
+mar