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Date: Wed, 9 Nov 2016 14:21:16 +0000 (GMT)
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cc: Dmitry Stogov <dmitry@zend.com>, Nikita Popov <nikita.ppv@gmail.com>
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Subject: PHP 5.6 static access valgrind issue
From: derick@derickrethans.nl (Derick Rethans)

Hi!

Through https://bugs.xdebug.org/view.php?id=1185 I ran into a bug in PHP 
proper. Apparently, this script:

	<?php

	class A {
		static private $a;

		static public function init() {
			self::$a = 123;
		}
	}

	A::init();

	echo 'succcess!';

And running it with "valgrind php -n index.php", produces:

	root@debian-8-64bit:/home/derick/xdebug-issue-1185# valgrind php -n index.php
	==760== Memcheck, a memory error detector
	==760== Copyright (C) 2002-2013, and GNU GPL'd, by Julian Seward et al.
	==760== Using Valgrind-3.10.0 and LibVEX; rerun with -h for copyright info
	==760== Command: php -n index.php
	==760== 
	==760== Conditional jump or move depends on uninitialised value(s)
	==760==    at 0x797992: zend_std_get_static_method (zend_object_handlers.c:1261)
	==760==    by 0x7B66FE: ZEND_INIT_STATIC_METHOD_CALL_SPEC_CONST_CONST_HANDLER (zend_vm_execute.h:3887)
	==760==    by 0x7A379F: execute_ex (zend_vm_execute.h:363)
	==760==    by 0x76E2AF: zend_execute_scripts (zend.c:1341)
	==760==    by 0x70CC87: php_execute_script (main.c:2613)
	==760==    by 0x81A990: do_cli (php_cli.c:998)
	==760==    by 0x431996: main (php_cli.c:1382)
	==760== 
	succcess!==760== 
	==760== HEAP SUMMARY:
	==760==     in use at exit: 96 bytes in 3 blocks
	==760==   total heap usage: 19,605 allocs, 19,602 frees, 3,589,979 bytes allocated
	==760== 
	==760== LEAK SUMMARY:
	==760==    definitely lost: 0 bytes in 0 blocks
	==760==    indirectly lost: 0 bytes in 0 blocks
	==760==      possibly lost: 0 bytes in 0 blocks
	==760==    still reachable: 96 bytes in 3 blocks
	==760==         suppressed: 0 bytes in 0 blocks
	==760== Rerun with --leak-check=full to see details of leaked memory
	==760== 
	==760== For counts of detected and suppressed errors, rerun with: -v
	==760== Use --track-origins=yes to see where uninitialised values come from
	==760== ERROR SUMMARY: 1 errors from 1 contexts (suppressed: 0 from 0)

This is with the latest PHP-5.6 branch, and the GCC that comes with 
Debian Jessie:

	root@debian-8-64bit:/home/derick/xdebug-issue-1185# gcc --version
	gcc (Debian 4.9.2-10) 4.9.2


Annoyingly, I can only produce this on a Debian Jessie (8.6) fresh install, and
not on my local machine. I can't seem to find the problem either, but I *can*
provide a VM and instructions to reproduce this. Or provide SSH access 
into it upon request.

Anybody wants to try and fix this? I'm going to see whether PHP 7.0 and 
7.1 have a similar issue too.

cheers,
Derick

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