Description:
------------
Script recursively calls class b()'s constructor.  Due to the use of alloca for execution of the constructor, the process Dies Horribly rather than issuing a valid error code (which would normally facilitate at least an error message.) when it runs out of stack.


Reproduce code:
---------------
<?php
class a {
    var $y;
}

class b extends a {
    function b() {
        $this->{get_parent_class($this)}();
    }
}

class c extends b {
    function c() {
        $this->{get_parent_class($this)}();
    }
}

$f = new c();
?>

Expected result:
----------------
I'd like to see the zend engine throw an error when it runs out of stack, but I don't see how (without moving off of alloca and taking a performance hit) it can be implemented.

I don't believe this is a security issue due to libc killing the process rather than returning an error which zend_execute.c doesn't catch.

I've worked around the code in question by rearchitecting my class hierarchy.  Looking forward to multiple inheritance in PHP5?



Actual result:
--------------
Backtrace Follows:
Program received signal EXC_BAD_ACCESS, Could not access memory.
0x00172a94 in _zend_is_inconsistent (ht=0x180638, file=0x0, line=0) at /Users/porwig/Development/php-4.3.3RC3/Zend/zend_hash.c:83
83      {
(gdb) bt
#0  0x00172a94 in _zend_is_inconsistent (ht=0x180638, file=0x0, line=0) at /Users/porwig/Development/php-4.3.3RC3/Zend/zend_hash.c:83
#1  0x00180638 in zend_fetch_var_address (opline=0x4e8868, Ts=0xbff80140, type=0) at /Users/porwig/Development/php-4.3.3RC3/Zend/zend_execute.c:581
#2  0x00182ea4 in execute (op_array=0x4e9fb8) at /Users/porwig/Development/php-4.3.3RC3/Zend/zend_execute.c:1248
#3  0x001853f0 in execute (op_array=0x4e9fb8) at /Users/porwig/Development/php-4.3.3RC3/Zend/zend_execute.c:1660
#4  0x001853f0 in execute (op_array=0x4e9fb8) at /Users/porwig/Development/php-4.3.3RC3/Zend/zend_execute.c:1660
... snip ...
#748 0x001853f0 in execute (op_array=0x4e9fb8) at /Users/porwig/Development/php-4.3.3RC3/Zend/zend_execute.c:1660
#749 0x001853f0 in execute (op_array=0x4eb488) at /Users/porwig/Development/php-4.3.3RC3/Zend/zend_execute.c:1660
#750 0x001853f0 in execute (op_array=0x4e6cf8) at /Users/porwig/Development/php-4.3.3RC3/Zend/zend_execute.c:1660
#751 0x0016c8d4 in zend_execute_scripts (type=8, retval=0x0, file_count=3) at /Users/porwig/Development/php-4.3.3RC3/Zend/zend.c:885
#752 0x0011f298 in php_execute_script (primary_file=0xbffff740) at /Users/porwig/Development/php-4.3.3RC3/main/main.c:1720
#753 0x0018cb64 in main (argc=2, argv=0xbffffc90) at /Users/porwig/Development/php-4.3.3RC3/sapi/cli/php_cli.c:818
#754 0x00001e44 in _start (argc=2, argv=0xbffffc90, envp=0xbffffc9c) at /SourceCache/Csu/Csu-45/crt.c:267
#755 0x00001cc4 in start ()
(gdb)