after a while, callbacks are not called on broken connection

[rainbow-alex]

Access denied errors (and possibly others) stop callbacks from being called, but only after some time has passed. That is:

expected: When connecting badly, the first query calls back with an error.
expected: If I query again (within the same stack frame), the callback gets an error.
expected: If I query again (soon, in a different stack frame), the callback gets an error.
unexpected: If I query yet again (some time later, in a different stack frame), the callback is never called.

Here is a simple script illustrating the problem. Note that the connection options are supposed to be nonsense, to cause the access denied error.

"use strict";

let mysql = require( "mysql" );

let db = mysql.createConnection( {
    user: "foo",
    database: "bar",
} );

function oops()
{
    db.query( "SELECT 1",
    function( err, v )
    {
        console.log( "error is", err );
    } );
}

oops();
oops();
process.nextTick( oops );
setTimeout( oops, 200 );

expected: 4x access denied
actual: 3x access denied