Description:
------------
I insert or update a row of a mysql table via mysqli_query. Then I try to get the number of affected rows via mysqli_affected_rows. It returns 1. Everything works fine so far. Then I dump the mysqli object via var_dump or print_r between the mysqli_query and mysqli_affected_rows calls.

Test script:
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$link = mysqli_connect($my_host, $my_username, $my_password, $my_dbname);

if ($link)
{
	mysqli_query($link, "create table `test` (`id` int not null auto_increment, `name` varchar(100) not null, primary key (`id`)) engine = MyISAM charset = utf8mb4 collate utf8mb4_general_ci");
	mysqli_query($link, "insert into `test` set `name` = 'Al Bundy'");
	var_dump($link);
	echo 'affected rows = ' . mysqli_affected_rows($link) . "\n";
	echo 'sqlstate error = ' . mysqli_sqlstate($link) . "\n";
}


Expected result:
----------------
I expected mysqli_affected_rows to return 1 because a dump of the mysqli object shouldn't change anything about its internal state.


Actual result:
--------------
But mysqli_affected_rows unexpectedly returns -1. mysqli_sqlstate doesn't show any error, returning '00000'.

I didn't experience this behavior if I use prepared statements and mysqli_stmt_affected_rows.