ID:               29493
 Updated by:       [EMAIL PROTECTED]
 Reported By:      msm at manley dot org
-Status:           Verified
+Status:           Closed
 Bug Type:         Unknown/Other Function
 Operating System: Linux, FreeBSD
 PHP Version:      5.0.0
 Assigned To:      moriyoshi
 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.




Previous Comments:
------------------------------------------------------------------------

[2004-08-09 00:37:29] [EMAIL PROTECTED]

Seems a side-effect of the fix I did for bug #25708.


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

[2004-08-06 16:35:22] msm at manley dot org

Sent patch to [EMAIL PROTECTED] that passes all of the PHP distribution
testcases for bug 25708 and all of the testcases above.

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

[2004-08-05 00:44:03] msm at manley dot org

That patch is no good. It causes the testcase for bug 25708 to fail.

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

[2004-08-04 23:46:02] msm at manley dot org

The problem lies in extract()'s use of the SEPARATE_ZVAL macro in
ext/standard/array.c. That macro actually makes a full copy of a ZVAL
if the ZVAL's refcount is > 1. 

I assume that's used when doing lazy copies, normally.

The existing extract() function uses SEPARATE_ZVAL_TO_MAKE_IS_REF to
set is_ref = 1 in the ZVAL. When the refcount on the extract()ed array
is 1, no copy is made and the extracted variables are refs to the array
member. When the refcount is > 1, a copy of the array entry gets made by
SEPARATE_ZVAL and the extracted variable end up as refs to the copy.

Here is a patch that I believe fixes the problem. So far a modified
version of PHP 5.0.0 has passed all the testcases with this patch in
place.



--- array.c     Wed Aug  4 15:54:40 2004
+++ array.c.msm Wed Aug  4 16:42:01 2004
@@ -1372,7 +1372,7 @@
                                if (extract_refs) {
                                        zval **orig_var;

-                                      
SEPARATE_ZVAL_TO_MAKE_IS_REF(entry);
+                                       (*(entry))->is_ref = 1;
                                        zval_add_ref(entry);

                                        if
(zend_hash_find(EG(active_symbol_table), final_name.c,
final_name.len+1, (void **) &orig_var) == SUCCESS) {

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

[2004-08-03 22:59:58] msm at manley dot org

Realizing I'm mostly conversing with myself here:

I'm not completely certain, but I think the issue is on line 1375 of
ext/standard/array.c

SEPARATE_ZVAL_TO_MAKE_IS_REF(entry);

If I follow the logic back through the twisty little maze of zend.h
macros, it would appear that when that macro is called and the refcount
on the original entry is > 1, SEPARATE_ZVAL ends up copying the entry
entirely.

But that would mean the individual entries in a array/hash have the
same refcount as the array in general. Perhaps that's true? 

At this point I am in way deeper than I can figure, having never even
looked at the PHP source before today.

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

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the rest of the comments, please view the bug report online at
    http://bugs.php.net/29493

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