ID: 8937
User Update by: [EMAIL PROTECTED]
Old-Status: Feedback
Status: Open
Bug Type: Scripting Engine problem
Description: unset() in context with GLOBAL

My problem is, that old PHP3 scripts won´t work with PHP4, if they use such a 
construct.

And it is a bug in the meaning of "the program dosn't do, what I expect". Ok, the bug 
is documented, but look at the ERROR-ID #8972 for a case, that makes a much more 
surprising and unexpected effect.

Why can't PHP just overwrite the value with the value "UNSET" in the case of unsetting 
a reference - instead of removing the reference?

Previous Comments:
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[2001-03-06 08:10:47] [EMAIL PROTECTED]
So, what's the problem with your latest code? I do not see any.

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

[2001-01-28 18:53:34] [EMAIL PROTECTED]
Bug or feature. Thats the question. :)

Sorry, it IS a bug. 4 people have mentioned this and I found now a
test case, where no workarround exists.

But I found another problem in this context. Will make a new ticket.


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[2001-01-26 16:24:50] [EMAIL PROTECTED]
Sorry... forgot to read all the comments....

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[2001-01-26 16:14:57] [EMAIL PROTECTED]
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] [EMAIL PROTECTED]
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);

?>


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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


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