ID:               34790
 Updated by:       [EMAIL PROTECTED]
 Reported By:      savzen at gmail dot com
-Status:           Verified
+Status:           Feedback
 Bug Type:         PCRE related
 Operating System: Linux
 PHP Version:      5CVS, 4CVS (2005-10-08) (snap)
 New Comment:

Please try using this CVS snapshot:

  http://snaps.php.net/php5-latest.tar.gz
 
For Windows:
 
  http://snaps.php.net/win32/php5-win32-latest.zip

Tried latest CVS, works fine and no valgrind errors.


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

[2005-10-09 01:42:25] [EMAIL PROTECTED]

I've tried to fix the bug, but I couldn't find a clue.
The problem is triggered when destroying a hash table (in zend_hash.c),
but I don't know which hash table is. This should be much easier to a
Engine expert.
Anyway, I've made a simpler reproduce script, which is enough to
trigger valgrind errors.

<? preg_match_all('/(?P<word>the)/', '', $matches); ?>

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

[2005-10-09 00:17:13] [EMAIL PROTECTED]

Ouch... 193 valgrind errors :)

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

[2005-10-08 19:27:59] savzen at gmail dot com

Description:
------------
I used the function preg_match_all () WITHIN a function being called by
another function, with a named capturing group and assigned the match to
a variable using the named group as a key (name or number).

The variable assigned the value of the return becomes NULL

This happens in both the latest snapshots of PHP-4 and PHP-5 with PHP-5
giving a segmentation fault after NULL when "error_reporting (E_ALL)" is
at the top of the script

When the configure option --enable-debug is used PHP-5 gives UNKNOWN:0
instead of NULL and no segmentation fault

When NOT using a Named capturing group name and instead use a normal
capturing group the behaviour seems to stop. Assigning the matched
value by reference also seems to stop the behaviour. ie
var2=&var['named_key']

Reproduce code:
---------------
error_reporting(E_ALL);
function func1(){
        $words = func2();
        var_dump($words);
        $this_words = $words;
        return $this_words;
}
function func2(){
        $pattern = '(?P<word>(?:the))';
        $string = 'what the word and the other word the';
        preg_match_all('/'.$pattern.'/i', $string, $matches);
        $words = $matches['word'];
        $this_words = $words;
        var_dump($this_words);
        return $words;
}
func1();

Expected result:
----------------
array(4) {
  [0]=>
  string(3) "the"
  [1]=>
  string(3) "the"
  [2]=>
  string(3) "the"
  [3]=>
  string(3) "the"
}
array(4) {
  [0]=>
  string(3) "the"
  [1]=>
  string(3) "the"
  [2]=>
  string(3) "the"
  [3]=>
  string(3) "the"
}


Actual result:
--------------
array(4) {
  [0]=>
  string(3) "the"
  [1]=>
  string(3) "the"
  [2]=>
  string(3) "the"
  [3]=>
  string(3) "the"
}
NULL{php -4} UNKNOWN:0 {php-5 --enable-debug}
segmentation fault {php-5 without --enable-debug}

Backtrace (PHP-5 latest without enable-debug because it doesn't crash
when it is used)
---------------------------------------
(gdb) bt
#0  0x402429f2 in malloc () from /lib/i686/libc.so.6
Cannot access memory at address 0x18
(gdb)


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


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