Description:
------------
According to the manual one can expect PDO->errorInfo() to return an array with three elements.

"Return Values

PDO->errorInfo() returns an array of error information about the last operation performed by this database handle. The array consists of the following fields:
Element 	Information
0 	SQLSTATE error code (a five-character alphanumeric identifier defined in the ANSI SQL standard).
1 	Driver-specific error code.
2 	Driver-specific error message."
http://www.php.net/manual/en/function.PDO-errorInfo.php

The manual is wrong. PDO will not always return an array with three elements. There are two situations when you will get an array with only one element.

  1) driver has not set an error code yet
  2) IM001 - not implemented (= driver can't set an error code)

I'd appreciate if you either document this or fix PDO->errorInfo() to always return an array with three elements. My personal preference is change PDO->errorInfo(). I don't see any reason why people would have to use a complicated test like the following to avoid "undefined index" style messages:

if (count($info = $pdo->errorInfo()) == 3)
  die(sprintf("SQLSTATE %s, Driver info: %s/%s", $info[0], $info[1], $info[2])); 
else
  die(sprintf("SQLSTATE %s", $info[0]));

Note that this bug is somewhat related to the question raised in http://bugs.php.net/bug.php?id=44153 . 



Reproduce code:
---------------
nixnutz@ulflinux:~/php53> sapi/cli/php -r '$pdo=new PDO("sqlite:/tmp/foo.db"); var_dump($pdo->errorCode()); var_dump($pdo->errorInfo());'
string(0) ""
array(1) {
  [0]=>
  string(0) ""
}

nixnutz@ulflinux:~/php53> sapi/cli/php -r '$pdo=new PDO("mysql:dbname=phptest;unix_socket=/tmp/mysql.sock", "root", "root"); $pdo->getAttribute(-1); var_dump($pdo->errorCode()); var_dump($pdo->errorInfo());'

Warning: PDO::getAttribute(): SQLSTATE[IM001]: Driver does not support this function: driver does not support that attribute in Command line code on line 1
string(5) "IM001"
array(1) {
  [0]=>
  string(5) "IM001"
}


nixnutz@ulflinux:~/php53> sapi/cli/php -r '$pdo=new PDO("sqlite:/tmp/foo.db"); $pdo->getAttribute(-1); var_dump($pdo->errorCode()); var_dump($pdo->errorInfo());'

Warning: PDO::getAttribute(): SQLSTATE[IM001]: Driver does not support this function: driver does not support that attribute in Command line code on line 1
string(5) "IM001"
array(1) {
  [0]=>
  string(5) "IM001"
}

Expected result:
----------------
Always return an array with three elements. Make checking the errorInfo() easier.

Actual result:
--------------
See above. Array with only one element.