Parts of Spooled Debug Missing - Sometimes

[bhsmither]

I am still tracing this out, and maybe #3449 fixed it, but on a httpredir bounce, sometimes the first one or two dumps to the debug spool gets lost between script exits.

The sequence I am tracing is: Search using a word found only in one product. CubeCart should httpredir with ?_a=product&product_id=x The browser asks for that page. CubeCart should httpredir with appropriate /seo_url for x The browser asks for that page. CubeCart delivers that page.

On the page that is finally delivered, the debug is missing all the work that was done during the search.

[bhsmither]

So far, I have narrowed it down to:

In Debug->__destruct():
There is:
Session::getInstance()->set('debug_spool', array($this->display(true)));
In Session->set():
There is:
$_SESSION[$namespace][$name] = merge_array($_SESSION[$namespace][$name], $value);
In function merge_array($first, $second):
There is:
$first[(string)$key[$i]] = (is_array($second[$key[$i]])) ? array_merge($first[$key[$i]], $second[$key[$i]]) : $second[$key[$i]];

The two arrays to be merged are:

$first => array (size=1) [0] => string '<h2>Debug Output - /search?search[keywords]=Test ... ' (length=25796)
$second => array (size=1) [0] => string '<h2>Debug Output - /search?_a=product&product_id=1 ...' (length=15616)

Because $second is not empty and is an array, the merge will be attempted. The keys of $second, and the size of those keys, are:

$key => array (size=1) [0] => int 0
$size => '1'

This is index 0 of less than 1 ... Because $first[0] exists, and if $second[0] is an array, try to array_merge($first[0], $second[0]) and assign to $first['0']. But if $second[0] is not an array, use $second[0] directly assign to $first['0'].

Here's the problem. $second[0] is a string. (And so is $first[0] by the way.)

[bhsmither]

I hope you can find a better solution. I didn't want to mess with any of the legacy code.

So, this is what I did:

In Debug->__destruct():
From:
Session::getInstance()->set('debug_spool', array($this->display(true)));
To:
// Fetch the debug_spool array, where the default return is an array, and remove empty elements.
$debug_spool = array_filter($GLOBALS['session']->get('debug_spool', 'system', array()));
// Push the latest debug content string.
$debug_spool[] = $this->display(true);
// The new debug_spool overwrites.
Session::getInstance()->set('debug_spool', $debug_spool, 'system', true);