Watch destruction of widgets around OnAAction() method

fpdfsdk/fpdfxfa/cpdfxfa_docenvironment.cpp

Index: fpdfsdk/fpdfxfa/cpdfxfa_docenvironment.cpp
diff --git a/fpdfsdk/fpdfxfa/cpdfxfa_docenvironment.cpp b/fpdfsdk/fpdfxfa/cpdfxfa_docenvironment.cpp
index 106d997e440493c95147a8a2385398256750c13b..d7a29959e98dec886b53edbcb1aef9f8d5c254f8 100644
--- a/fpdfsdk/fpdfxfa/cpdfxfa_docenvironment.cpp
+++ b/fpdfsdk/fpdfxfa/cpdfxfa_docenvironment.cpp
@@ -538,7 +538,8 @@ void CPDFXFA_DocEnvironment::SetFocusWidget(CXFA_FFDoc* hDoc,
     return;
 
   if (!hWidget) {
-    m_pDocument->GetSDKDoc()->SetFocusAnnot(nullptr);
+    CPDFSDK_Annot::ObservedPtr pNull;
+    m_pDocument->GetSDKDoc()->SetFocusAnnot(pNull);
     return;
   }
 
@@ -548,7 +549,7 @@ void CPDFXFA_DocEnvironment::SetFocusWidget(CXFA_FFDoc* hDoc,
     if (!pPageView)
       continue;
 
-    CPDFSDK_Annot* pAnnot = pPageView->GetAnnotByXFAWidget(hWidget);
+    CPDFSDK_Annot::ObservedPtr pAnnot(pPageView->GetAnnotByXFAWidget(hWidget));
     if (pAnnot) {
       m_pDocument->GetSDKDoc()->SetFocusAnnot(pAnnot);
       break;