From 0510d5c757fbbf5b54ecd0aefe81338e4be9f40e Mon Sep 17 00:00:00 2001
From: Matteo Scaramuccia <moodle@matteoscaramuccia.com>
Date: Tue, 25 Jul 2017 09:07:20 +0200
Subject: [PATCH] MDL-59583 dml: fixed breaking change added w/ MariaDB 10.2.7+

---
 lib/dml/mariadb_native_moodle_database.php |  6 ++++++
 lib/dml/mysqli_native_moodle_database.php  | 14 +++++++++++++-
 2 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/lib/dml/mariadb_native_moodle_database.php b/lib/dml/mariadb_native_moodle_database.php
index ffc77965932..48debee57ce 100644
--- a/lib/dml/mariadb_native_moodle_database.php
+++ b/lib/dml/mariadb_native_moodle_database.php
@@ -88,6 +88,12 @@ class mariadb_native_moodle_database extends mysqli_native_moodle_database {
         return array('description'=>$this->mysqli->server_info, 'version'=>$version);
     }
 
+    protected function has_breaking_change_quoted_defaults() {
+        $version = $this->get_server_info()['version'];
+        // Breaking change since 10.2.7: MDEV-13132.
+        return version_compare($version, '10.2.7', '>=');
+    }
+
     /**
      * It is time to require transactions everywhere.
      *
diff --git a/lib/dml/mysqli_native_moodle_database.php b/lib/dml/mysqli_native_moodle_database.php
index bb6c519f3b1..1f70e7b4c8e 100644
--- a/lib/dml/mysqli_native_moodle_database.php
+++ b/lib/dml/mysqli_native_moodle_database.php
@@ -783,6 +783,14 @@ class mysqli_native_moodle_database extends moodle_database {
         return $structure;
     }
 
+    /**
+     * Indicates whether column information retrieved from `information_schema.columns` has default values quoted or not.
+     * @return boolean True when default values are quoted (breaking change); otherwise, false.
+     */
+    protected function has_breaking_change_quoted_defaults() {
+        return false;
+    }
+
     /**
      * Returns moodle column info for raw column from information schema.
      * @param stdClass $rawcolumn
@@ -794,7 +802,11 @@ class mysqli_native_moodle_database extends moodle_database {
         $info->name           = $rawcolumn->column_name;
         $info->type           = $rawcolumn->data_type;
         $info->meta_type      = $this->mysqltype2moodletype($rawcolumn->data_type);
-        $info->default_value  = $rawcolumn->column_default;
+        if ($this->has_breaking_change_quoted_defaults()) {
+            $info->default_value = trim($rawcolumn->column_default, "'");
+        } else {
+            $info->default_value = $rawcolumn->column_default;
+        }
         $info->has_default    = !is_null($rawcolumn->column_default);
         $info->not_null       = ($rawcolumn->is_nullable === 'NO');
         $info->primary_key    = ($rawcolumn->column_key === 'PRI');