In Scheduler plugin, when a user created a new slot, and that slot conflicted with an existing slot, both would disappear.

Fix inserts slot after after deleting conflicting ones.

— a/mod/scheduler/teacherview.controller.php
+++ b/mod/scheduler/teacherview.controller.php
@@ -89,6 +89,8 @@ function scheduler_action_doaddsession($scheduler, $formdata) {
foreach ($conflicts as $conflict)

+ $DB->insert_record('scheduler_slots', $slot, false, true);
+ $countslots++;
}
} else {
$DB->insert_record('scheduler_slots', $slot, false, true);

TEST:

• Create new scheduler activity
• Using "Add Slots" create a slot (slot 1).
• Using "Add Slots" to create a conflicting (same time and date) slot, ticking the "Force when overlap" (slot 2)
  Without patch (current):
• Slot 1 and Slot 2 both disappear
  With patch (expected):
• The Slot 1 is deleted and Slot 2 is created.