From: geoff at variosoft dot com
Operating system: Linux
PHP version: 4.3.8
PHP Bug Type: Arrays related
Bug description: Non-existent keys evaluate to string
Description:
------------
In a multi-dimensional assoc array with a depth of x, an unset key at
depth x+1 evaluates unexpectedly to a string when using var_dump() - the
1st char of the array value.
This means that isset() returns TRUE when testing for the unset key, which
makes it hard to test for non-existence.
An unset key with a depth of x+2 works as expected.
This behaviour has been replicated in 4.3.8 and the 5 previous versions,
all on Linux.
Reproduce code:
---------------
$foo['one']['two'] = 'test-value' ;
if( isset( $foo['one']['two']['three'] ) )
{
print( "Unexpected isset(): evaluated to TRUE<br>" ) ;
}
else
{
print( "Expected isset(): evaluated to FALSE<br>" ) ;
}
print( 'var_dump() output (expecting NULL):<br>' ) ;
var_dump( $foo['one']['two']['three'] ) ;
Expected result:
----------------
As I am testing for an unset key, I expected isset() to return FALSE, and
var_dump() to return NULL.
Actual result:
--------------
In fact, isset() returns TRUE.
var_dump() gives a clue as to what is going on: it returns the first
character of the key's value string.
For unset keys of a depth of x + 2, isset() returns FALSE and var_dump()
returns NULL, as expected.
--
Edit bug report at http://bugs.php.net/?id=29848&edit=1
--
Try a CVS snapshot (php4): http://bugs.php.net/fix.php?id=29848&r=trysnapshot4
Try a CVS snapshot (php5.0): http://bugs.php.net/fix.php?id=29848&r=trysnapshot50
Try a CVS snapshot (php5.1): http://bugs.php.net/fix.php?id=29848&r=trysnapshot51
Fixed in CVS: http://bugs.php.net/fix.php?id=29848&r=fixedcvs
Fixed in release: http://bugs.php.net/fix.php?id=29848&r=alreadyfixed
Need backtrace: http://bugs.php.net/fix.php?id=29848&r=needtrace
Need Reproduce Script: http://bugs.php.net/fix.php?id=29848&r=needscript
Try newer version: http://bugs.php.net/fix.php?id=29848&r=oldversion
Not developer issue: http://bugs.php.net/fix.php?id=29848&r=support
Expected behavior: http://bugs.php.net/fix.php?id=29848&r=notwrong
Not enough info: http://bugs.php.net/fix.php?id=29848&r=notenoughinfo
Submitted twice: http://bugs.php.net/fix.php?id=29848&r=submittedtwice
register_globals: http://bugs.php.net/fix.php?id=29848&r=globals
PHP 3 support discontinued: http://bugs.php.net/fix.php?id=29848&r=php3
Daylight Savings: http://bugs.php.net/fix.php?id=29848&r=dst
IIS Stability: http://bugs.php.net/fix.php?id=29848&r=isapi
Install GNU Sed: http://bugs.php.net/fix.php?id=29848&r=gnused
Floating point limitations: http://bugs.php.net/fix.php?id=29848&r=float
