diff --git a/fpdfsdk/include/fsdk_baseform.h b/fpdfsdk/include/fsdk_baseform.h
index b15fba6..16a23bf 100644
--- a/fpdfsdk/include/fsdk_baseform.h
+++ b/fpdfsdk/include/fsdk_baseform.h
@@ -261,32 +261,27 @@
 
 #define CPDFSDK_Annots				CFX_ArrayTemplate<CPDFSDK_Annot*>
 #define CPDFSDK_SortAnnots			CGW_ArrayTemplate<CPDFSDK_Annot*>
-class CBA_AnnotIterator 
+class CBA_AnnotIterator
 {
 public:
 	CBA_AnnotIterator(CPDFSDK_PageView* pPageView, const CFX_ByteString& sType, const CFX_ByteString& sSubType);
-	virtual ~CBA_AnnotIterator();
-	
-	virtual CPDFSDK_Annot*				GetFirstAnnot();
-	virtual CPDFSDK_Annot*				GetLastAnnot();
-	virtual CPDFSDK_Annot*				GetNextAnnot(CPDFSDK_Annot* pAnnot);
-	virtual CPDFSDK_Annot*				GetPrevAnnot(CPDFSDK_Annot* pAnnot);
-	
-	virtual void						Release(){delete this;}
-	
+	~CBA_AnnotIterator();
+
+	CPDFSDK_Annot*				GetFirstAnnot();
+	CPDFSDK_Annot*				GetLastAnnot();
+	CPDFSDK_Annot*				GetNextAnnot(CPDFSDK_Annot* pAnnot);
+	CPDFSDK_Annot*				GetPrevAnnot(CPDFSDK_Annot* pAnnot);
+
 private:
 	void								GenerateResults();
 	static int							CompareByLeft(CPDFSDK_Annot* p1, CPDFSDK_Annot* p2);
 	static int							CompareByTop(CPDFSDK_Annot* p1, CPDFSDK_Annot* p2);
-	
 	static CPDF_Rect					GetAnnotRect(CPDFSDK_Annot* pAnnot);
-	
-private:
+
 	CPDFSDK_PageView*					m_pPageView;
 	CFX_ByteString						m_sType;
 	CFX_ByteString						m_sSubType;
 	int									m_nTabs;
-	
 	CPDFSDK_Annots						m_Annots;
 };
 
diff --git a/fpdfsdk/src/fsdk_baseform.cpp b/fpdfsdk/src/fsdk_baseform.cpp
index 6c8069b..0c0492d 100644
--- a/fpdfsdk/src/fsdk_baseform.cpp
+++ b/fpdfsdk/src/fsdk_baseform.cpp
@@ -4,6 +4,7 @@
  
 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
 
+#include "../../third_party/base/nonstd_unique_ptr.h"
 #include "../include/fsdk_define.h"
 #include "../include/fsdk_mgr.h"
 #include "../include/fsdk_baseannot.h"
@@ -1727,22 +1728,13 @@
 
 CPDFSDK_Widget* CPDFSDK_InterForm::GetSibling(CPDFSDK_Widget* pWidget, FX_BOOL bNext) const
 {
-	ASSERT(pWidget != NULL);
+    nonstd::unique_ptr<CBA_AnnotIterator> pIterator(
+        new CBA_AnnotIterator(pWidget->GetPageView(), "Widget", ""));
 
-	CBA_AnnotIterator* pIterator = new CBA_AnnotIterator(pWidget->GetPageView(), "Widget", "");
-	ASSERT(pIterator != NULL);
-
-	CPDFSDK_Widget* pRet = NULL;
-
-	if (bNext)
-		pRet = (CPDFSDK_Widget*)pIterator->GetNextAnnot(pWidget);
-	else
-		pRet = (CPDFSDK_Widget*)pIterator->GetPrevAnnot(pWidget);
-
-	pIterator->Release();
-	
-	return pRet;
-
+    if (bNext) {
+        return (CPDFSDK_Widget*)pIterator->GetNextAnnot(pWidget);
+    }
+    return (CPDFSDK_Widget*)pIterator->GetPrevAnnot(pWidget);
 }
 
 CPDFSDK_Widget*	CPDFSDK_InterForm::GetWidget(CPDF_FormControl* pControl) const