Description:
------------
Whenever php make a call to a postgresql database function with the 'RAISE NOTICE' statement in it then it leaks memory.

With the provided memTest.php script, if one run it on php 7.1 or 7.2, there is a memory leak reported. Testing on php 7.0 leak memory but by comparison it is much less. Please see below result.

Here is a test result with php 7.2:

# php -v
PHP 7.2.2-1+ubuntu16.04.1+deb.sury.org+1 (cli) (built: Feb  1 2018 16:01:26) ( NTS )
Copyright (c) 1997-2018 The PHP Group
Zend Engine v3.2.0, Copyright (c) 1998-2018 Zend Technologies
    with Zend OPcache v7.2.2-1+ubuntu16.04.1+deb.sury.org+1, Copyright (c) 1999-2018, by Zend Technologies

# ./memTest.php
php-psql memory leak test for function with 'RAISE NOTICE'
After 1000 runs memory lost = 84920 bytes

Here is a test result with php 7.1:

# php -v
PHP 7.1.13-1+ubuntu16.04.1+deb.sury.org+1 (cli) (built: Jan  5 2018 13:26:45) ( NTS )
Copyright (c) 1997-2017 The PHP Group
Zend Engine v3.1.0, Copyright (c) 1998-2017 Zend Technologies
    with Zend OPcache v7.1.13-1+ubuntu16.04.1+deb.sury.org+1, Copyright (c) 1999-2017, by Zend Technologies

# ./memTest.php 
php-psql memory leak test for function with 'RAISE NOTICE'
After 1000 runs memory lost = 84920 bytes

Here is a test result with php 7.0:

# php -v
PHP 7.0.22-0ubuntu0.16.04.1 (cli) ( NTS )
Copyright (c) 1997-2017 The PHP Group
Zend Engine v3.0.0, Copyright (c) 1998-2017 Zend Technologies
    with Zend OPcache v7.0.22-0ubuntu0.16.04.1, Copyright (c) 1999-2017, by Zend Technologies

# ./memTest.php 
php-psql memory leak test for function with 'RAISE NOTICE'
After 1000 runs memory lost =  112 bytes


Test script:
---------------
# memTest.php script
# usage: ./memTest.php

#!/usr/bin/env php
<?php

const NUM_RUNS = 1000;

function addNoticeFunction($con)
{
    $query = "CREATE OR REPLACE FUNCTION test_function () RETURNS void AS $$ BEGIN RAISE NOTICE 'Hellow World!'; END; $$ LANGUAGE plpgsql;"; // this function will cause memory leak
    //$query = "CREATE OR REPLACE FUNCTION test_function () RETURNS void AS $$ BEGIN END; $$ LANGUAGE plpgsql;"; // this function will not cause memory leak
    $rs_client = pg_query($con, $query) or die("Cannot execute query: $query\n");
    if ($rs_client)
      pg_free_result($rs_client);

}

function makeAQuery($con)
{
    $query = "SELECT test_function()"; // lose 424 byte each run
    $rs_client = pg_query($con, $query) or die("Cannot execute query: $query\n");
    if ($rs_client)
      pg_free_result($rs_client);
}

function runQueryTests ($con)
{
    $before = memory_get_usage();
    for ($i = 0; $i < NUM_RUNS; ++$i) {
        makeAQuery($con);
    }
    $after = memory_get_usage();
    printf("After %d runs memory lost = %4d bytes\n", NUM_RUNS, $after - $before);
}

print("php-psql memory leak test for function with 'RAISE NOTICE'\n");
$con = pg_pconnect("host=172.17.0.1 user=postgres") or go_die("Could not connect to server\n");
addNoticeFunction($con);
runQueryTests($con);
pg_close($con);


?>


Expected result:
----------------
There should be 0 memory leak

Actual result:
--------------
There was 84920 bytes of memory leak after running the script