PHP 4.0 Bug #8937 Updated: unset() in context with GLOBAL

ID: 8937 Updated by: derick Reported By: aulbach@unter.franken.de Old-Status: Closed Status: Open Bug Type: Scripting Engine problem Assigned To: Comments: Sorry... forgot to read all the comments.... Previous Comments: --------------------------------------------------------------------------- [2001-01-26 16:14:57] derick@php.net This isn't a bug, but a feature =) If you use GLOBAL within a function it creates a reference to the orignal variabele, this reference is local to the function. SO if you unset() this variabele, you're only unsetting the reference (and thus not the GLOBAL variabele). This is documented behavior (from the unset() manual page): If a globalized variable is unset() inside of a function, only the local variable is destroyed. The variable in the calling environment will retain the same value as before unset() was called. --------------------------------------------------------------------------- [2001-01-26 14:19:15] aulbach@unter.franken.de The mentioned workarround (unset($GLOBALS['x'])) dosn't work with my testscript. The result is exactly the same as with the first version of my script. I really have GREAT TROUBLES to upgrade this old application to PHP4. Result: '/hugo/bla/fasel' '/hugo/bla' '/hugo' DIR called with function test1(): Array ( [/hugo] => 1 [/hugo/bla] => 1 [/hugo/bla/fasel] => 1 ) '/hugo/bla/fasel' '/hugo/bla' '/hugo' DIR called with function test2(): Array ( [/hugo/bla/fasel/test] => 1 [/hugo] => 1 [/hugo/bla] => 1 [/hugo/bla/fasel] => 1 ) Script: <? function test1 ($dir) { GLOBAL $x; unset($GLOBALS["x"]); $x[$dir]=true; mydirname($dir); } function test2 ($dir) { GLOBAL $x; ####### unset($x); no unset! $x[$dir]=true; mydirname($dir); } function mydirname ($dir) { GLOBAL $x; $dir=ereg_Replace('/[^/]*$','',$dir); if (!empty($dir)) { echo "'$dir'<br>"; flush(); mydirname($dir); $x[$dir]=true; } } $dir="/hugo/bla/fasel/test"; # first char must be '/' ! unset($x); test1($dir); echo "DIR called with function test1(): "; print_r($x); echo "<br>"; unset($x); test2($dir); echo "DIR called with function test2(): "; print_r($x); ?> --------------------------------------------------------------------------- [2001-01-26 14:05:26] aulbach@unter.franken.de Of course I know that it is already documented. First mentioned in August 1999! Havn't mentioned this, cause it is not relevant. A bug is bug, and the other tickets have been closed, but the bug was remaining. 4 (or more?) other guys had the same trouble with this behaviour. How many others havn't reported this bug? I know minimum 2 others, which havn't. Sorry, but it IS a bug and a workarround is not a bugfix and my opinion is, that you make it too easy for yourself to change the state of this ticket to "closed". But I will not change it for you. I'll respect your decission. --------------------------------------------------------------------------- [2001-01-26 11:54:16] jmoore@php.net Thats thanks to Bjorn ;) Not my sig.. --------------------------------------------------------------------------- [2001-01-26 11:52:29] jmoore@php.net Have a closer look at http://bugs.php.net/bugs.php?id=1971 and the commentary of Zeev. You have to use unset($GLOBALS["x"]); -- Björn Schotte b.schotte@pangora.com http://rent-a-phpwizard.de/ bjoern@baer.main.de --------------------------------------------------------------------------- The remainder of the comments for this report are too long. To view the rest of the comments, please view the bug report online. Full Bug description available at: http://bugs.php.net/?id=8937