Fix bug #65387

Add GC support to dual_it. This is still missing AppendIterator
support.

Author: nikic

NEWS

@@ -2,6 +2,9 @@ PHP                                                                        NEWS
 |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
 ?? ??? ????, PHP 8.0.0rc2
 
+- SPL.
+  . Fixed bug #65387 (Circular references in SPL iterators are not garbage
+    collected). (Nikita)
 
 01 Oct 2020, PHP 8.0.0rc1
 

ext/spl/spl_iterators.c

@@ -2119,6 +2119,52 @@ static void spl_dual_it_free_storage(zend_object *_object)
 }
 /* }}} */
 
+static HashTable *spl_dual_it_get_gc(zend_object *obj, zval **table, int *n)
+{
+	spl_dual_it_object *object = spl_dual_it_from_obj(obj);
+	zend_get_gc_buffer *gc_buffer = zend_get_gc_buffer_create();
+
+	if (!Z_ISUNDEF(object->inner.zobject)) {
+		zend_get_gc_buffer_add_zval(gc_buffer, &object->inner.zobject);
+	}
+
+	switch (object->dit_type) {
+		case DIT_Unknown:
+		case DIT_Default:
+		case DIT_IteratorIterator:
+		case DIT_NoRewindIterator:
+		case DIT_InfiniteIterator:
+		case DIT_LimitIterator:
+		case DIT_RegexIterator:
+		case DIT_RecursiveRegexIterator:
+			/* Nothing to do */
+			break;
+		case DIT_AppendIterator:
+			// TODO
+			/*zend_get_gc_buffer_add_obj(gc_buffer, &object->u.append.iterator->std);
+			if (Z_TYPE(object->u.append.zarrayit) != IS_UNDEF) {
+				zend_get_gc_buffer_add_zval(gc_buffer, &object->u.append.zarrayit);
+			}*/
+			break;
+		case DIT_CachingIterator:
+		case DIT_RecursiveCachingIterator:
+			zend_get_gc_buffer_add_zval(gc_buffer, &object->u.caching.zcache);
+			break;
+		case DIT_CallbackFilterIterator:
+		case DIT_RecursiveCallbackFilterIterator:
+			if (object->u.cbfilter) {
+				zend_get_gc_buffer_add_zval(gc_buffer, &object->u.cbfilter->fci.function_name);
+				if (object->u.cbfilter->fci.object) {
+					zend_get_gc_buffer_add_obj(gc_buffer, object->u.cbfilter->fci.object);
+				}
+			}
+			break;
+	}
+
+	zend_get_gc_buffer_use(gc_buffer, table, n);
+	return zend_std_get_properties(obj);
+}
+
 /* {{{ spl_dual_it_new */
 static zend_object *spl_dual_it_new(zend_class_entry *class_type)
 {
@@ -3191,6 +3237,7 @@ PHP_MINIT_FUNCTION(spl_iterators)
 	spl_handlers_dual_it.clone_obj = NULL;
 	spl_handlers_dual_it.dtor_obj = spl_dual_it_dtor;
 	spl_handlers_dual_it.free_obj = spl_dual_it_free_storage;
+	spl_handlers_dual_it.get_gc = spl_dual_it_get_gc;
 
 	spl_ce_RecursiveIteratorIterator->get_iterator = spl_recursive_it_get_iterator;
 

ext/spl/tests/bug65387.phpt

@@ -0,0 +1,54 @@
+--TEST--
+Bug #67387: Circular references in SPL iterators are not garbage collected
+--FILE--
+<?php
+
+$it = new ArrayIterator([1, 2, 3]);
+// Inner.
+$it[] = $it;
+
+// Callback
+$it2 = new CallbackFilterIterator($it, function($elem) use(&$it2) {
+    return true;
+});
+
+// Callback object
+new class {
+    public function __construct() {
+        $it = new ArrayIterator([1, 2, 3]);
+        $this->it = new CallbackFilterIterator($it, function($elem) {
+            return true;
+        });
+    }
+};
+
+// Recursive callback
+$it = new RecursiveArrayIterator([1, 2, 3]);
+$it2 = new RecursiveCallbackFilterIterator($it, function($elem) use(&$it2) {
+    return true;
+});
+
+// Cache
+$it = new ArrayIterator();
+$it2 = new CachingIterator($it, CachingIterator::FULL_CACHE);
+$it2[] = $it2;
+$it2->next();
+
+// Recursive cache
+$it = new RecursiveArrayIterator();
+$it2 = new RecursiveCachingIterator($it, CachingIterator::FULL_CACHE);
+$it2[] = $it2;
+$it2->next();
+
+// Append
+/* TODO
+$it = new ArrayIterator();
+$it2 = new AppendIterator();
+$it[] = $it2;
+$it2->append($it);
+ */
+
+?>
+===DONE===
+--EXPECT--
+===DONE===