ID:               44182
 Updated by:       [EMAIL PROTECTED]
 Reported By:      robin_fernandes at uk dot ibm dot com
-Status:           Open
+Status:           Closed
 Bug Type:         Arrays related
 Operating System: *
 PHP Version:      5CVS, 6CVS (2008-10-27)
 New Comment:

This bug has been fixed in CVS.

Snapshots of the sources are packaged every three hours; this change
will be in the next snapshot. You can grab the snapshot at
http://snaps.php.net/.
 
Thank you for the report, and for helping us make PHP better.

Thanks for the patch


Previous Comments:
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[2008-10-27 13:20:20] robin_fernandes at uk dot ibm dot com

Confirmed this bug (and bug 44181) still present on:
PHP 5.2.7RC3-dev (cli) (built: Oct 27 2008 11:40:07) 
PHP 5.3.0alpha3-dev (cli) (built: Oct 27 2008 14:06:30) 
PHP 6.0.0-dev (cli) (built: Oct 27 2008 12:39:36)

------------------------------------------------------------------------

[2008-10-27 13:01:24] [EMAIL PROTECTED]

Does this bug exist in HEAD, PHP_5_3 and PHP_5_2 branches? And in
today's versions of them?

------------------------------------------------------------------------

[2008-10-25 13:52:02] robin_fernandes at uk dot ibm dot com

The patch URL? Seems OK to me, perhaps it was temporarily broken.

In any case, here's another one: 
http://soal.org/php/extract.patch.txt

------------------------------------------------------------------------

[2008-10-25 13:25:36] [EMAIL PROTECTED]

That url does not work..

------------------------------------------------------------------------

[2008-02-20 09:29:24] robin_fernandes at uk dot ibm dot com

I think the problem is that extract() can set the is_ref flag on zvals
without splitting them (i.e. zvals which have more than 1 copy-on-write
references can get their is_ref flag set).

>From array.c:
...
} else {
  if (Z_REFCOUNT_P(var_array) > 1 || *entry ==
EG(uninitialized_zval_ptr)) {
    SEPARATE_ZVAL_TO_MAKE_IS_REF(entry);
  } else {
    Z_SET_ISREF_PP(entry);  // <-- causes damage if entry has COW
references!
  }
...

I believe that the only reliable way to fix this would be to make
extract() take its array argument as PREFER_REF.

This way, we can safely split array elements away from their
copy-on-write references, and still end up with a zval that belongs to
the original array.

I'm attaching a patch which implements this and fixes this bug, as well
as bug http://bugs.php.net/44181.

Disclaimer:
- I am not an internals expert. I might have disregarded some
scenarios. Feedback welcome!
- Patch tested on Windows XP 32bit only.

Patch against php6.0-200802191530 snap (includes test cases):
http://pastebin.ca/910172

------------------------------------------------------------------------

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the rest of the comments, please view the bug report online at
    http://bugs.php.net/44182

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