From 6a36fa82c7cba8303c57b8d64a5dbcc555c4715a Mon Sep 17 00:00:00 2001
From: Long TRAN <longthanhtran@users.noreply.github.com>
Date: Mon, 7 Feb 2022 05:29:03 +0700
Subject: [PATCH] Fix #19047, fix #19118: Fix deprecated preg_match() passing
 null parameters #2 in db\mysql\Schema.php

---
 framework/CHANGELOG.md                  |  1 +
 framework/db/mysql/Schema.php           |  1 +
 tests/framework/db/mysql/SchemaTest.php | 31 +++++++++++++++++++++++--
 3 files changed, 31 insertions(+), 2 deletions(-)

diff --git a/framework/CHANGELOG.md b/framework/CHANGELOG.md
index 054abdf6a4f..051b6e54e9c 100644
--- a/framework/CHANGELOG.md
+++ b/framework/CHANGELOG.md
@@ -12,6 +12,7 @@ Yii Framework 2 Change Log
 - Bug #19187: Fix `yii\filters\PageCache` to store original headers names instead of normalized ones (bizley)
 - Bug #19191: Change `\Exception` to `\Throwable` in `BadRequestHttpException` and `HttpException` (Dmitrijlin)
 - Bug #19204: Support numbers in Inflector::camel2words (longthanhtran)
+- Bug #19047: Fix deprecated preg_match() passing null parameters #2 in db\mysql\Schema.php (longthanhtran)
 
 
 2.0.44 December 30, 2021
diff --git a/framework/db/mysql/Schema.php b/framework/db/mysql/Schema.php
index 87ae9ade780..babb7d2aa9a 100644
--- a/framework/db/mysql/Schema.php
+++ b/framework/db/mysql/Schema.php
@@ -294,6 +294,7 @@ protected function loadColumnSchema($info)
              * See details here: https://mariadb.com/kb/en/library/now/#description
              */
             if (($column->type === 'timestamp' || $column->type === 'datetime')
+                && isset($info['default'])
                 && preg_match('/^current_timestamp(?:\(([0-9]*)\))?$/i', $info['default'], $matches)) {
                 $column->defaultValue = new Expression('CURRENT_TIMESTAMP' . (!empty($matches[1]) ? '(' . $matches[1] . ')' : ''));
             } elseif (isset($type) && $type === 'bit') {
diff --git a/tests/framework/db/mysql/SchemaTest.php b/tests/framework/db/mysql/SchemaTest.php
index b5419821e8e..4fd27951f25 100644
--- a/tests/framework/db/mysql/SchemaTest.php
+++ b/tests/framework/db/mysql/SchemaTest.php
@@ -8,6 +8,8 @@
 namespace yiiunit\framework\db\mysql;
 use yii\db\Expression;
 
+use yii\db\mysql\ColumnSchema;
+use yii\db\mysql\Schema;
 use yiiunit\framework\db\AnyCaseValue;
 
 /**
@@ -101,7 +103,7 @@ public function testAlternativeDisplayOfDefaultCurrentTimestampInMariaDB()
          * We do not have a real database MariaDB >= 10.2.3 for tests, so we emulate the information that database
          * returns in response to the query `SHOW FULL COLUMNS FROM ...`
          */
-        $schema = new \yii\db\mysql\Schema();
+        $schema = new Schema();
         $column = $this->invokeMethod($schema, 'loadColumnSchema', [[
             'field' => 'emulated_MariaDB_field',
             'type' => 'timestamp',
@@ -114,11 +116,36 @@ public function testAlternativeDisplayOfDefaultCurrentTimestampInMariaDB()
             'comment' => '',
         ]]);
 
-        $this->assertInstanceOf(\yii\db\mysql\ColumnSchema::className(), $column);
+        $this->assertInstanceOf(ColumnSchema::className(), $column);
         $this->assertInstanceOf(Expression::className(), $column->defaultValue);
         $this->assertEquals('CURRENT_TIMESTAMP', $column->defaultValue);
     }
 
+    /**
+     * When displayed in the INFORMATION_SCHEMA.COLUMNS table, a default CURRENT TIMESTAMP is provided
+     * as NULL.
+     *
+     * @see https://github.com/yiisoft/yii2/issues/19047
+     */
+    public function testAlternativeDisplayOfDefaultCurrentTimestampAsNullInMariaDB()
+    {
+        $schema = new Schema();
+        $column = $this->invokeMethod($schema, 'loadColumnSchema', [[
+            'field' => 'emulated_MariaDB_field',
+            'type' => 'timestamp',
+            'collation' => NULL,
+            'null' => 'NO',
+            'key' => '',
+            'default' => NULL,
+            'extra' => '',
+            'privileges' => 'select,insert,update,references',
+            'comment' => '',
+        ]]);
+
+        $this->assertInstanceOf(ColumnSchema::className(), $column);
+        $this->assertEquals(NULL, $column->defaultValue);
+    }
+
     public function getExpectedColumns()
     {
         $version = $this->getConnection()->getSchema()->getServerVersion();