Hello Sara,
nice catch, fix looks pretty correct to me
best regards
marcus
Wednesday, July 5, 2006, 10:59:35 PM, you wrote:
> When executing ZEND_FETCH_OBJ_IS on a non-object, the handler dispatches
> to zend_fetch_property_address_read_helper with type==BP_VAR_IS and ends
> up generating an error (isset() is supposed to be quiet) here:
> if (Z_TYPE_P(container) != IS_OBJECT ||
> !Z_OBJ_HT_P(container)->read_property) {
> zend_error(E_NOTICE, "Trying to get property of non-object");
> *retval = EG(uninitialized_zval_ptr);
> SELECTIVE_PZVAL_LOCK(*retval, &opline->result);
> AI_USE_PTR(EX_T(opline->result.u.var).var);
> It's cousin ZEND_FETCH_DIM_IS winds up at zend_fetch_dimension_address()
> where the non-arrayness of op1 is handled via these case statements:
> case IS_NULL: {
> /* for read-mode only */
> if (result) {
> result->var.ptr_ptr = &EG(uninitialized_zval_ptr);
> PZVAL_LOCK(*result->var.ptr_ptr);
> }
> if (type==BP_VAR_W || type==BP_VAR_RW) {
> zend_error(E_WARNING, "Cannot use a NULL value as an array");
> }
> break;
> }
> default: {
> switch (type) {
> case BP_VAR_UNSET:
> zend_error(E_WARNING, "Cannot unset offset in a
> non-array variable");
> /* break missing intentionally */
> case BP_VAR_R:
> case BP_VAR_IS:
> retval = &EG(uninitialized_zval_ptr);
> break;
> default:
> retval = &EG(error_zval_ptr);
> break;
> }
> if (result) {
> result->var.ptr_ptr = retval;
> PZVAL_LOCK(*result->var.ptr_ptr);
> }
> if (type==BP_VAR_W || type==BP_VAR_RW) {
> zend_error(E_WARNING, "Cannot use a scalar value as an
> array");
> }
> }
> Which indicate the expected behavior of silent failure. It's probably
> gone undetected till now as it requires fetching a property or dimension
> offset from a property in a third (non-object) variable within an isset()
> statement:
> $foo = NULL;
> isset($foo->bar->baz);
> Unless someone can suggest why Objects should be noisy inside isset(),
> I'd like to suggest the following fix:
> Index: Zend/zend_vm_def.h
> ===================================================================
> RCS file: /repository/ZendEngine2/zend_vm_def.h,v
> retrieving revision 1.120
> diff -u -r1.120 zend_vm_def.h
> --- Zend/zend_vm_def.h 13 Jun 2006 12:56:20 -0000 1.120
> +++ Zend/zend_vm_def.h 5 Jul 2006 20:52:41 -0000
> @@ -1176,7 +1176,9 @@
> if (Z_TYPE_P(container) != IS_OBJECT ||
> !Z_OBJ_HT_P(container)->read_property) {
> - zend_error(E_NOTICE, "Trying to get property of non-object");
> + if (type != BP_VAR_IS) {
> + zend_error(E_NOTICE, "Trying to get property of
> non-object");
> + }
> *retval = EG(uninitialized_zval_ptr);
> SELECTIVE_PZVAL_LOCK(*retval, &opline->result);
> AI_USE_PTR(EX_T(opline->result.u.var).var);
> I suggest only excluding BP_VAR_IS since the matching behavior for
> unset()/DIM is to throw a notice. I could potentially see excluding
> BP_VAR_R in order to match read/DIM, but personally I never liked that
> behavior :)
> -Sara
Best regards,
Marcus
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