Description:
------------
odbc_specialcolumns() is supposed to accept a 7th parameter
$nullable; this is no longer the case as of PHP 7.0.0[1].  Since
this parameter cannot be passed anymore, some arbitrary value will
be used internally, which likely lets the function fail (which
happens to me, see test script), or uses some arbitrary (allowed)
value.

[1] <https://github.com/php/php-src/commit/e8fcd52ef1d2bb215aa40a4b8507a760079e0497#diff-e7dfa5ff1b47832265dcb9426b0af690L3608-R3608>

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

$conn = odbc_connect($dsn, $user, $pass);
var_dump(($res = odbc_specialcolumns($conn, SQL_BEST_ROWID, 'TutorialDB', 'dbo', 'TEST', SQL_SCOPE_CURROW)));
var_dump(odbc_fetch_array($res));


Expected result:
----------------
resource(5) of type (odbc result)
array(8) {
  ["SCOPE"]=>
  string(1) "0"
  ["COLUMN_NAME"]=>
  string(2) "id"
  ["DATA_TYPE"]=>
  string(1) "4"
  ["TYPE_NAME"]=>
  string(3) "int"
  ["COLUMN_SIZE"]=>
  string(2) "10"
  ["BUFFER_LENGTH"]=>
  string(1) "4"
  ["DECIMAL_DIGITS"]=>
  string(1) "0"
  ["PSEUDO_COLUMN"]=>
  string(1) "1"
}

Actual result:
--------------
Warning: odbc_specialcolumns(): SQL error: Failed to fetch error message, SQL state HY000 in SQLSpecialColumns in %s on line %d
bool(false)

Warning: odbc_fetch_array() expects parameter 1 to be resource, boolean given in %s on line %d
NULL