<?php

function test()
{
throw new exception();
}

test();

?>

Consider the following code and a debugging session that has an exception breakpoint set on "Fatal error":
<?php

function test()
{
throw new exception();
}

test();

?>

Expected behaviour:

An uncaught exception triggers a fatal error, which is caught as a breakpoint by Xdebug. Xdebug transfers control over to the client. When the client asks for a stacktrace using the DBGp command 'stack_get', the user gets back a proper DBGp response, containing a stacktrace containing entries for the function 'test' and the function '{main}'.

Actual behaviour in 2.0RC4

The uncaught exception indeed triggers a fatal error which is properly caught by Xdebug. When requesting the stacktrace (without a depth specificier) you get an empty response:

(cmd) stack_get -i waa3
<?xml version="1.0" encoding="iso-8859-1"?>
<response xmlns="urn:debugger_protocol_v1" xmlns:xdebug="http://xdebug.org/dbgp/xdebug" command="stackget" transaction
id="waa3"></response>

Full debugclient conversation:

Waiting for debug server to connect.
Connect
<?xml version="1.0" encoding="iso-8859-1"?>
<init xmlns="urn:debugger_protocol_v1" xmlns:xdebug="http://xdebug.org/dbgp/xdebug" fileuri="file:///C%3A%5CProgram%20Fi
les%5Cxampp%5Cxampp%5Chtdocs%5Cxdebug%5Cexception.php" language="PHP" protocol_version="1.0" appid="424" idekey="0"><eng
ine version="2.0.0RC4-dev"><![CDATA[Xdebug]]></engine><author><![CDATA[Derick Rethans]]></author><url><![CDATA[http://xd
ebug.org]]></url><copyright><![CDATA[Copyright (c) 2002-2007 by Derick Rethans]]></copyright></init>

(cmd) breakpoint_set -i waa0 -t exception -x "Fatal error"
<?xml version="1.0" encoding="iso-8859-1"?>
<response xmlns="urn:debugger_protocol_v1" xmlns:xdebug="http://xdebug.org/dbgp/xdebug" command="breakpoint_set" transac
tion_id="waa0" id="4240002"></response>

(cmd) run -i waa
<?xml version="1.0" encoding="iso-8859-1"?>
<response xmlns="urn:debugger_protocol_v1" xmlns:xdebug="http://xdebug.org/dbgp/xdebug" command="run" transaction_id="wa
a" status="break" reason="ok"><xdebug:message filename="C:\Program Files\xampp\xampp\htdocs\xdebug\exception.php" lineno
="5" exception="Fatal error"><![CDATA[Uncaught exception 'Exception' in C:\Program Files\xampp\xampp\htdocs\xdebug\excep
tion.php:5
Stack trace:
#0 C:\Program Files\xampp\xampp\htdocs\xdebug\exception.php(8): test()
#1 {main}
thrown]]></xdebug:message></response>

(cmd) stack_get -i waa3
<?xml version="1.0" encoding="iso-8859-1"?>
<response xmlns="urn:debugger_protocol_v1" xmlns:xdebug="http://xdebug.org/dbgp/xdebug" command="stackget" transaction
id="waa3"></response>

(cmd) stack_get -i waa4 -d 0
<?xml version="1.0" encoding="iso-8859-1"?>
<response xmlns="urn:debugger_protocol_v1" xmlns:xdebug="http://xdebug.org/dbgp/xdebug" command="stackget" transaction
id="waa4"><error code="1"><message><![CDATA[parse error in command]]></message></error></response>

(cmd) stack_get -i waa5 -d 1
<?xml version="1.0" encoding="iso-8859-1"?>
<response xmlns="urn:debugger_protocol_v1" xmlns:xdebug="http://xdebug.org/dbgp/xdebug" command="stackget" transaction
id="waa4" status="break" reason="ok"><error code="301"><message><![CDATA[stack depth invalid]]></message></error></respo
nse>