Description:
------------
PDO::__construct() will always throw a PDOException if the connection fails regardless of which PDO::ATTR_ERRMODE is currently set.  The PDOException has a public property $errorInfo which corresponds to PDO::errorInfo() or PDOStatement::errorInfo().

When PDO::__construct() throws a PDOException say, because of a database server issue, the public property PDOException::$errorInfo is set to NULL and the return value from PDOException::getCode() is not the expected string SQLSTATE error code.

I would have expected a non-NULL PDOException::$errorInfo to be set when the exception is caught.

Test script:
---------------
<?php

// Valid DSN, but with wrong password to trigger the exception
$dsn = 'pgsql:host=localhost;dbname=test;user=foo;password=wrongpass';
try {
  $pdo = new \PDO($dsn, null, null);
} catch (\PDOException $e) {
  var_dump($e->errorInfo);
  var_dump($e->getCode());
  var_dump($e->getMessage());
}

?>

Expected result:
----------------
array(3) {
  [0] =>
  string(5) "08006"
  [1] =>
  int(7)
  [2] =>
  string(53) "FATAL:  password authentication failed for user "foo""
}
string(5) "08006"
string(73) "SQLSTATE[08006] [7] FATAL:  password authentication failed for user "foo""


Actual result:
--------------
NULL
int(7)
string(73) "SQLSTATE[08006] [7] FATAL:  password authentication failed for user "foo""