- For internal classes we must auto generate the abstract class flags.

# Actually providing the flags while registering the class is not possible
# since that would require a major API change.

Author: helly25

Zend/zend_compile.c

@@ -2144,8 +2144,12 @@ ZEND_API void zend_do_inheritance(zend_class_entry *ce, zend_class_entry *parent
 	zend_hash_merge(&ce->constants_table, &parent_ce->constants_table, (void (*)(void *)) zval_add_ref, NULL, sizeof(zval *), 0);
 	zend_hash_merge_ex(&ce->function_table, &parent_ce->function_table, (copy_ctor_func_t) do_inherit_method, sizeof(zend_function), (merge_checker_func_t) do_inherit_method_check, ce);
 	do_inherit_parent_constructor(ce);
-	
-	zend_verify_abstract_class(ce TSRMLS_CC);
+
+	if (ce->ce_flags & ZEND_ACC_IMPLICIT_ABSTRACT_CLASS && ce->type == ZEND_INTERNAL_CLASS) {
+		ce->ce_flags |= ZEND_ACC_EXPLICIT_ABSTRACT_CLASS;
+	} else {
+		zend_verify_abstract_class(ce TSRMLS_CC);
+	}
 }