MySQL Statement has a empty query result when the response field has changed, also Segmentation fault

[Yurunsoft]

Description

The following code:

<?php

declare(strict_types=1);

function getPDO(): PDO
{
    return new PDO('mysql:host=127.0.0.1;dbname=test', 'root', 'root', [
        PDO::ATTR_ERRMODE           => PDO::ERRMODE_EXCEPTION,
        PDO::ATTR_EMULATE_PREPARES  => false,
    ]);
}

function testPDO(): void
{
    $pdo = getPDO();
    $pdo->exec(<<<'SQL'
    DROP TABLE IF EXISTS `test`
    SQL);
    $pdo->exec(<<<'SQL'
    CREATE TABLE `test`  (
      `id` int(10) UNSIGNED NOT NULL AUTO_INCREMENT,
      `name` varchar(32) CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci NOT NULL,
      PRIMARY KEY (`id`) USING BTREE,
      INDEX `name`(`name`) USING BTREE
    ) ENGINE = InnoDB CHARACTER SET = utf8mb4 COLLATE = utf8mb4_unicode_ci ROW_FORMAT = Dynamic;
    SQL);
    $pdo->exec(<<<'SQL'
    INSERT INTO `test` (`name`) VALUES ('test1');
    SQL);

    $pdo2 = getPDO();
    $stmt = $pdo2->prepare('select * from test');
    var_dump('PDO-1:', $stmt->execute(), $stmt->fetchAll());

    $stmt->closeCursor(); // Optional. Segmentation fault (core dumped)

    $pdo->exec(<<<'SQL'
    ALTER TABLE `test`
    ADD COLUMN `a` varchar(255) NOT NULL DEFAULT '';
    SQL);

    var_dump('PDO-2:', $stmt->execute(), $stmt->fetchAll());
}

function getMysqli(): mysqli
{
    return new mysqli('127.0.0.1', 'root', 'root', 'test');
}

function testMysqli(): void
{
    $mysqli = getMysqli();
    $mysqli->query(<<<'SQL'
    DROP TABLE IF EXISTS `test`
    SQL);
    $mysqli->query(<<<'SQL'
    CREATE TABLE `test`  (
      `id` int(10) UNSIGNED NOT NULL AUTO_INCREMENT,
      `name` varchar(32) CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci NOT NULL,
      PRIMARY KEY (`id`) USING BTREE,
      INDEX `name`(`name`) USING BTREE
    ) ENGINE = InnoDB CHARACTER SET = utf8mb4 COLLATE = utf8mb4_unicode_ci ROW_FORMAT = Dynamic;
    SQL);
    $mysqli->query(<<<'SQL'
    INSERT INTO `test` (`name`) VALUES ('test1');
    SQL);

    $mysqli2 = getMysqli();
    $stmt = $mysqli2->prepare('select * from test');
    var_dump('mysqli-1:', $stmt->execute(), $stmt->get_result()->fetch_all());

    $mysqli->query(<<<'SQL'
    ALTER TABLE `test`
    ADD COLUMN `a` varchar(255) NOT NULL DEFAULT '';
    SQL);

    var_dump('mysqli-2:', $stmt->execute(), $stmt->get_result()->fetch_all());
}

testMysqli();
testPDO();

Resulted in this output:

string(9) "mysqli-1:"
bool(true)
array(1) {
  [0]=>
  array(2) {
    [0]=>
    int(1)
    [1]=>
    string(5) "test1"
  }
}
string(9) "mysqli-2:"
bool(true)
array(0) {
}
string(6) "PDO-1:"
bool(true)
array(1) {
  [0]=>
  array(4) {
    ["id"]=>
    int(1)
    [0]=>
    int(1)
    ["name"]=>
    string(5) "test1"
    [1]=>
    string(5) "test1"
  }
}
Segmentation fault (core dumped)

But I expected this output instead:

string(9) "mysqli-1:"
bool(true)
array(1) {
  [0]=>
  array(2) {
    [0]=>
    int(1)
    [1]=>
    string(5) "test1"
  }
}
string(9) "mysqli-2:"
bool(true)
array(1) {
  [0]=>
  array(3) {
    [0]=>
    int(1)
    [1]=>
    string(5) "test1"
    [2]=>
    string(0) ""
  }
}
string(6) "PDO-1:"
bool(true)
array(1) {
  [0]=>
  array(4) {
    ["id"]=>
    int(1)
    [0]=>
    int(1)
    ["name"]=>
    string(5) "test1"
    [1]=>
    string(5) "test1"
  }
}
string(6) "PDO-2:"
bool(true)
array(1) {
  [0]=>
  array(6) {
    ["id"]=>
    int(1)
    [0]=>
    int(1)
    ["name"]=>
    string(5) "test1"
    [1]=>
    string(5) "test1"
    ["a"]=>
    string(0) ""
    [2]=>
    string(0) ""
  }
}

This bug affects mysqli, pdo_mysql.

I will fix this issue later.

PHP Version

PHP 8.1.21

Operating System

No response