#22836 [Opn]: returning reference to uninitialized variable
ID: 22836
User updated by: brunswim at seas dot upenn dot edu
Reported By: brunswim at seas dot upenn dot edu
Status: Open
Bug Type: Scripting Engine problem
Operating System: Debian Linux 2.4.18
PHP Version: 4.3.1
New Comment:
For the record, the output I am getting for this script is:
string(3) "foo"
foo
string(3) "foo"
foo
NULL
foo
NULL
foo
NULL
foo
NULL
foo
NULL
foo
NULL
foo
Previous Comments:
------------------------------------------------------------------------
[2003-03-23 22:53:07] brunswim at seas dot upenn dot edu
f() returns a reference to an uninitialized variable $a. In subsequent
calls, this appears to corrupt the local variable $x. The following
script demonstrates the problem.
<?
function &f() {
$x = "foo";
var_dump($x);
print "<br>\n$x<br>\n";
return($a);
}
for ($i = 0; $i < 8; $i++) {
$h =& f();
}
?>
On the third call to f(), $x prints fine but is reported to be NULL by
var_dump(). Operations on $x will subsequently cause unexpected
behavior.
We can change the behavior of $x by adding the line:
$y = "bar";
after the line:
$x = "foo";
If we do this, printing $x returns "bar" but var_dump() still returns
NULL.
------------------------------------------------------------------------
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Thread (8 messages)