ID: 17959 Updated by: [EMAIL PROTECTED] Reported By: [EMAIL PROTECTED] -Status: Open +Status: Analyzed Bug Type: Scripting Engine problem Operating System: linux PHP Version: 4.2.1 New Comment:
Related to bug #20993(http://bugs.php.net/20993) Previous Comments: ------------------------------------------------------------------------ [2002-12-19 12:12:56] [EMAIL PROTECTED] I grabbed Apache/1.3.27 built and installed it. Next I grabbed php4-STABLE-200212182230 built and installed it. The same test-case presented in this bug report failed. I also grabbed php4-200212191630 a few minutes ago built and installed it. Again, the very same test-case in this bug report failed. --patrick ------------------------------------------------------------------------ [2002-12-07 01:46:07] [EMAIL PROTECTED] Please try using this CVS snapshot: http://snaps.php.net/php4-latest.tar.gz For Windows: http://snaps.php.net/win32/php4-win32-latest.zip Could you confirm that the problem still exists in latest CVS and if it does ,please provide a SMALL (10 or so) line script that could be used to replicate the problem. ------------------------------------------------------------------------ [2002-11-27 22:57:56] [EMAIL PROTECTED] I have experienced similar problems with PHP on Linux 2.4.x. It only seems to occur in very weird circumstances where you have a reference pointing (yes I know references are not pointers) to an array element. My only test cases are much larger that those presented by "[EMAIL PROTECTED]" as they involve production code. The one piece of information I can offer which may be of some use is that in my case, the problem can be eliminated by removing an uneeded "global" statement (the reference was already in scope). I realize that sounds absurd, but I have a case where "global" actually breaks the reference. When I comment out the global statement, the reference doesn't get wiped out. I know the reference is global because it was created in $GLOBALS. I know this seems strange, but I can var_dump it before and after and the only thing that changes is me commenting out the global statement. ------------------------------------------------------------------------ [2002-07-29 06:50:20] [EMAIL PROTECTED] <?php // Dear Php developer, // // After considering your explanation of what exactly 'global $ptr' // is i changed my code to strictly use $GLOBALS['ptr']. However, // after doing so my program still didn't function properly! // // I had to work a bit harder to come up with a simplified example // for you. I believe i have done so below. // // Please pay close attention to the notes w/in comments explaining // strange conditions that would make this sample code to work as // expected. Now I'm certain there EXISTS a serious problem with // the Php engine when processing this code. // // Thanks, // --patrick // define array we plan to navigate. $top = array ( 'name' => 'top', 'A' => array ( 'name' => 'A', 'A_a' => array ( 'name' => 'A_a', 'fn_1' => 'Aa_fn_1', 'fn_2' => 'Aa_fn_2', 'fn_3' => 'Aa_fn_3', 'A_a_1' => array ( 'name' => 'A_a_1', 'fn_1' => 'Aa1_fn_1', 'fn_2' => 'Aa1_fn_2', ), 'A_a_2' => array ( 'name' => 'A_a_2', 'fn_1' => 'Aa2_fn_1', 'fn_2' => 'Aa2_fn_2', ), ), ), ); // setup "parent references" for each of the nodes. $top['parent'] = null; $top['A']['parent'] = &$top; $top['A']['A_a']['parent'] = &$top['A']; $top['A']['A_a']['A_a_1']['parent'] = &$top['A']['A_a']; $top['A']['A_a']['A_a_2']['parent'] = &$top['A']['A_a']; //$top['A']['A_a']['A_a_1']['parent'] = &$top['A']['A_a']; // // Note! // Here if we uncomment the above line the sample code will // magically WORK! // // Why does the order of initialization matter!? And will the // code now break elsewhere? // setup our reference to $top. $ptr is what should change // on every call to change_ptr(name). $ptr = &$top; // change_ptr( name ) does the following w/some verbose // messages to display the state of variables in question. // // if ( ptr[name] ) // ptr = ptr[name]; // function change_ptr( $name ) { printf( " change_ptr($name) " ); if ( $GLOBALS['ptr'][$name] ) { // Setting up string for later printing. $before_change = sprintf( "before: \$GLOBALS['ptr']['name'] = %s", $GLOBALS['ptr']['name'] ); $GLOBALS['ptr'] = &$GLOBALS['ptr'][$name]; $after_change = sprintf( "after: \$GLOBALS['ptr']['name'] = %s", $GLOBALS['ptr']['name'] ); printf( "<font color=\"green\"><b>CHANGED</b></font>:\n" ); printf( " %s\n %s", $before_change, $after_change ); } else printf( "<font color=\"red\"><b>NO CHANGE!</b></font>" ); printf( "<br>\n" ); } ?> <pre> <? // All of the following calls should succeed and print // 'CHANGED'. However, you will notice that the last call // will fail to change $ptr to point to the 'parent' of // $top['A']['A_a']['A_a_2']. // change_ptr('A'); change_ptr('A_a'); change_ptr('A_a_1'); change_ptr('parent'); change_ptr('A_a_2'); change_ptr('parent'); ?> </pre> ------------------------------------------------------------------------ [2002-07-23 16:24:54] [EMAIL PROTECTED] think of the "global $p;" construct as a shortcut for "$p = &$GLOBALS['p'];" so by assigning a new reference you are breaking the one to the global variable so you have to explicitly assign to $GLOBALS["p"] here (marked as documentation problem) ------------------------------------------------------------------------ The remainder of the comments for this report are too long. To view the rest of the comments, please view the bug report online at http://bugs.php.net/17959 -- Edit this bug report at http://bugs.php.net/?id=17959&edit=1
