This script works just fine for me. Can you:

• upgrade to Xdebug 2.1.1

And then explain exactly when you get this problem.

• What are you doing?
• What is the command line?
• What are the PHP.ini settings for Xdebug (only)... etc.

The exact code from Expression Engine:

<?php
class EE_Functions {
var $action_ids = array();
function fetch_action_id($class, $method)
{
if ($class == '' OR $method == '')
{
return FALSE;
}

    $this->action_ids[ucfirst($class)][$method] = $method;

    return 'AID:'.ucfirst($class).':'.$method.RD;
}

}
$obj = new EE_Functions;
echo $obj->fetch_action_id("class", "method");

?>

This code works on production server without xdebug. On my local enviroinment it dies without any messages even in log on the line $this->action_ids[ucfirst($class)][$method] = $method;

If I assign ucfirst($class) to a variable and use that variable as array index it works fine.

xdebug settings are:

xdebug.remote_enable=On
xdebug.remote_host=localhost
xdebug.remote_port=9000
xdebug.remote_handler="dbgp"
xdebug.remote_autostart=off
xdebug.remote_mode=req
xdebug.show_mem_delta=On
xdebug.auto_trace=On
xdebug.collect_assignments=On
xdebug.profiler_enable=On
xdebug.show_exception_trace=On
xdebug.show_local_vars=On
xdebug.overload_var_dump=On
xdebug.show_local_vars=1
html_errors=On
xdebug.max_nesting_level = 5000

I do not get a crash here, but I do see memory reading errors with valgrind.

I've fixed the crash for Xdebug 2.2.0, but the real fix will have to wait.

Right now, we print ???, but we need to see whether we can figure out the actual value.