Added parameter "default_dbname" to pdo_pgsql driver which can be used to...

Added parameter "default_dbname" to pdo_pgsql driver which can be used to override the default database

docs/en/reference/configuration.rst

@@ -250,6 +250,8 @@ pdo\_pgsql
 -  ``dbname`` (string): Name of the database/schema to connect to.
 -  ``charset`` (string): The charset used when connecting to the
    database.
+-  ``default_dbname`` (string): Override the default database(postgres)
+   to connect to.
 -  ``sslmode`` (string): Determines whether or with what priority
    a SSL TCP/IP connection will be negotiated with the server.
    See the list of available modes:

lib/Doctrine/DBAL/Driver/PDOPgSql/Driver.php

@@ -88,12 +88,13 @@ class Driver extends AbstractPostgreSQLDriver
 
         if (isset($params['dbname'])) {
             $dsn .= 'dbname=' . $params['dbname'] . ' ';
+        } elseif (isset($params['default_dbname'])) {
+            $dsn .= 'dbname=' . $params['default_dbname'] . ' ';
         } else {
             // Used for temporary connections to allow operations like dropping the database currently connected to.
             // Connecting without an explicit database does not work, therefore "postgres" database is used
             // as it is certainly present in every server setup.
             $dsn .= 'dbname=postgres' . ' ';
-        }
 
         if (isset($params['sslmode'])) {
             $dsn .= 'sslmode=' . $params['sslmode'] . ' ';

tests/Doctrine/Tests/DBAL/Functional/Driver/PDOPgSql/DriverTest.php

@@ -2,6 +2,7 @@
 
 namespace Doctrine\Tests\DBAL\Functional\Driver\PDOPgSql;
 
+use Doctrine\DBAL\Connection;
 use Doctrine\DBAL\Driver\PDOPgSql\Driver;
 use Doctrine\Tests\DBAL\Functional\Driver\AbstractDriverTest;
 
@@ -20,6 +21,26 @@ class DriverTest extends AbstractDriverTest
         }
     }
 
+    public function testDefaultDatabaseOption()
+    {
+        $params = $this->_conn->getParams();
+        $dbName = $params['dbname'];
+        $params['default_dbname'] = $dbName;
+        unset($params['dbname']);
+
+        $connection = new Connection(
+            $params,
+            $this->_conn->getDriver(),
+            $this->_conn->getConfiguration(),
+            $this->_conn->getEventManager()
+        );
+
+        $this->assertSame(
+            $dbName,
+            $this->driver->getDatabase($connection)
+        );
+    }
+
     /**
      * @group DBAL-1146
      */