Description:
------------
The fact that PHP5 issues an E_WARNING on illegal string offset use, gives a problem on checking values with isset and is_array. Furthermore it does not behave consistent.

Might not be a real bug, since it is the 'Backward Incompatible Changes' list, still the behavior seems to buggy to me.

Reproduce code:
---------------
test.php:
<?php
$a = 'this is not an array';

if(isset($a['foo']))
     print '1';
if(isset($a['foo']['bar']))
     print '2';
if(isset($a['foo']['bar']['doo']))
     print '3';

?>

test2.php
<?php
$a = 'this is not an array';

if(is_array($a['foo']))
     print '1';
if(is_array($a['foo']['bar']))
     print '2';
if(is_array($a['foo']['bar']['doo']))
     print '3';

?>


Expected result:
----------------
Nothing!

Maybe fatal error at line 4 in both scripts, would be ok, but not very niced designed, and doesn't fit well into the type loose scheme of PHP. IMHO.

Actual result:
--------------
Fatal error: Cannot use string offset as an array in
/var/www/sites/test.php on line 8


Fatal error: Cannot use string offset as an array in
/var/www/sites/test2.php on line 6