#29848 [NEW]: Non-existent keys evaluate to string

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