Git commits in Moodle 3.9.15 by Huong Nguyen

commit 47c211ba0eec1d33bf5e4c3b9ac9e409a49181bd
Author: Huong Nguyen <huongnv13@gmail.com>
Date:   Fri, 06 May 2022 13:21:39 +0800
Tag:    v3.9.15

MDL-72029 Lesson: Prevent arbitrary file read when importing lesson questions in blackboard format


commit 9f270d956e238a185e47f7f47e0971f652360445
Author: Huong Nguyen <huongnv13@gmail.com>
Date:   Fri, 06 May 2022 12:30:15 +0800
Tag:    v3.9.15

MDL-72029 lib: Prevent path traversal for clean_param with PARAM_SAFEPATH