Fixed IBM DB2 tests

Author: morozov

lib/Doctrine/DBAL/Driver/IBMDB2/DB2Connection.php

@@ -134,7 +134,7 @@ public function lastInsertId(?string $name = null) : string
      */
     public function beginTransaction() : bool
     {
-        db2_autocommit($this->conn, DB2_AUTOCOMMIT_OFF);
+        return db2_autocommit($this->conn, DB2_AUTOCOMMIT_OFF);
     }
 
     /**
@@ -145,7 +145,8 @@ public function commit() : bool
         if (! db2_commit($this->conn)) {
             throw new DB2Exception(db2_conn_errormsg($this->conn));
         }
-        db2_autocommit($this->conn, DB2_AUTOCOMMIT_ON);
+
+        return db2_autocommit($this->conn, DB2_AUTOCOMMIT_ON);
     }
 
     /**
@@ -156,7 +157,8 @@ public function rollBack() : bool
         if (! db2_rollback($this->conn)) {
             throw new DB2Exception(db2_conn_errormsg($this->conn));
         }
-        db2_autocommit($this->conn, DB2_AUTOCOMMIT_ON);
+
+        return db2_autocommit($this->conn, DB2_AUTOCOMMIT_ON);
     }
 
     /**

lib/Doctrine/DBAL/Platforms/DB2Platform.php

@@ -291,7 +291,7 @@ public function getListTableColumnsSQL(string $table, ?string $database = null)
                  c.scale,
                  c.identity,
                  tc.type AS tabconsttype,
-                 c.remarks AS comment,
+                 COALESCE(c.remarks, '') AS comment,
                  k.colseq,
                  CASE
                  WHEN c.generated = 'D' THEN 1
@@ -528,7 +528,7 @@ public function getAlterTableSQL(TableDiff $diff)
 
             $comment = $this->getColumnComment($column);
 
-            if ($comment === null || $comment === '') {
+            if ($comment === '') {
                 continue;
             }
 

lib/Doctrine/DBAL/Schema/DB2SchemaManager.php

@@ -84,12 +84,10 @@ protected function _getPortableTableColumnDefinition(array $tableColumn) : Colum
             'fixed'         => (bool) $fixed,
             'default'       => $default,
             'autoincrement' => (bool) $tableColumn['autoincrement'],
-            'notnull'       => (bool) ($tableColumn['nulls'] === 'N'),
+            'notnull'       => $tableColumn['nulls'] === 'N',
             'scale'         => null,
             'precision'     => null,
-            'comment'       => isset($tableColumn['comment']) && $tableColumn['comment'] !== ''
-                ? $tableColumn['comment']
-                : null,
+            'comment'       => $tableColumn['comment'],
             'platformOptions' => [],
         ];
 

tests/Doctrine/Tests/DBAL/Functional/Schema/Db2SchemaManagerTest.php

@@ -23,7 +23,7 @@ public function testGetBooleanColumn() : void
         self::assertInstanceOf(BooleanType::class, $columns['bool']->getType());
         self::assertInstanceOf(BooleanType::class, $columns['bool_commented']->getType());
 
-        self::assertNull($columns['bool']->getComment());
+        self::assertSame('', $columns['bool']->getComment());
         self::assertSame("That's a comment", $columns['bool_commented']->getComment());
     }