Git commits in Moodle 3.8.x by David Matamoros

commit f24a2515cb358eab9f52147f68235ec6949af3b2
Author: David Matamoros <davidmc@moodle.com>
Date:   Wed, 30 Sep 2020 18:03:44 +0800
Tag:    v3.8.6

MDL-69805 mod_data: Freeze comment field if comments disabled

commit 21ad9531d069af41b43369a7bba7e5eb7ca69e6a
Author: David Matamoros <davidmc@moodle.com>
Date:   Mon, 02 Sep 2019 20:42:24 +0800
Tag:    v3.8.0-beta

MDL-66354 core_calendar: Notices in error.log on calendar events

commit 79b9f905b1ad250f3c9d2afa1bc9aacc33a67937
Author: David Matamoros <davidmc@moodle.com>
Date:   Thu, 23 May 2019 23:21:27 +0800
Tag:    v3.8.0-beta

MDL-65699 core_calendar: Check string exists for event types