Ensure CJS_Return() with error always includes a message.

Change the signature of the constructors to make it impossible to
do this otherwise.

Change-Id: I14e88d98a1128f2d599459ce9337cd6d079469fe
Reviewed-on: https://pdfium-review.googlesource.com/34531
Reviewed-by: dsinclair <dsinclair@chromium.org>
Commit-Queue: Tom Sepez <tsepez@chromium.org>

21 files changed, 138 insertions, 137 deletions

diff --git a/fxjs/xfa/cjx_container.cpp b/fxjs/xfa/cjx_container.cpp
index e5dbfe8258..0e58a7ea22 100644
--- a/fxjs/xfa/cjx_container.cpp
+++ b/fxjs/xfa/cjx_container.cpp
@@ -27,7 +27,7 @@ CJX_Container::~CJX_Container() {}
 CJS_Return CJX_Container::getDelta(
     CFX_V8* runtime,
     const std::vector<v8::Local<v8::Value>>& params) {
-  return CJS_Return(true);
+  return CJS_Return();
 }
 
 CJS_Return CJX_Container::getDeltas(
diff --git a/fxjs/xfa/cjx_datawindow.cpp b/fxjs/xfa/cjx_datawindow.cpp
index cdb6aab207..1f5b6ec7b6 100644
--- a/fxjs/xfa/cjx_datawindow.cpp
+++ b/fxjs/xfa/cjx_datawindow.cpp
@@ -27,25 +27,25 @@ CJX_DataWindow::~CJX_DataWindow() {}
 CJS_Return CJX_DataWindow::moveCurrentRecord(
     CFX_V8* runtime,
     const std::vector<v8::Local<v8::Value>>& params) {
-  return CJS_Return(true);
+  return CJS_Return();
 }
 
 CJS_Return CJX_DataWindow::record(
     CFX_V8* runtime,
     const std::vector<v8::Local<v8::Value>>& params) {
-  return CJS_Return(true);
+  return CJS_Return();
 }
 
 CJS_Return CJX_DataWindow::gotoRecord(
     CFX_V8* runtime,
     const std::vector<v8::Local<v8::Value>>& params) {
-  return CJS_Return(true);
+  return CJS_Return();
 }
 
 CJS_Return CJX_DataWindow::isRecordGroup(
     CFX_V8* runtime,
     const std::vector<v8::Local<v8::Value>>& params) {
-  return CJS_Return(true);
+  return CJS_Return();
 }
 
 void CJX_DataWindow::recordsBefore(CFXJSE_Value* pValue,
diff --git a/fxjs/xfa/cjx_delta.cpp b/fxjs/xfa/cjx_delta.cpp
index 1da5953ea1..9732f4eecb 100644
--- a/fxjs/xfa/cjx_delta.cpp
+++ b/fxjs/xfa/cjx_delta.cpp
@@ -24,7 +24,7 @@ CJS_Return CJX_Delta::restore(CFX_V8* runtime,
                               const std::vector<v8::Local<v8::Value>>& params) {
   if (!params.empty())
     return CJS_Return(JSGetStringFromID(JSMessage::kParamError));
-  return CJS_Return(true);
+  return CJS_Return();
 }
 
 void CJX_Delta::currentValue(CFXJSE_Value* pValue,
diff --git a/fxjs/xfa/cjx_eventpseudomodel.cpp b/fxjs/xfa/cjx_eventpseudomodel.cpp
index d2364c8f32..a6c5560b03 100644
--- a/fxjs/xfa/cjx_eventpseudomodel.cpp
+++ b/fxjs/xfa/cjx_eventpseudomodel.cpp
@@ -174,22 +174,22 @@ CJS_Return CJX_EventPseudoModel::emit(
     const std::vector<v8::Local<v8::Value>>& params) {
   CFXJSE_Engine* pScriptContext = GetDocument()->GetScriptContext();
   if (!pScriptContext)
-    return CJS_Return(true);
+    return CJS_Return();
 
   CXFA_EventParam* pEventParam = pScriptContext->GetEventParam();
   if (!pEventParam)
-    return CJS_Return(true);
+    return CJS_Return();
 
   CXFA_FFNotify* pNotify = GetDocument()->GetNotify();
   if (!pNotify)
-    return CJS_Return(true);
+    return CJS_Return();
 
   CXFA_FFWidgetHandler* pWidgetHandler = pNotify->GetWidgetHandler();
   if (!pWidgetHandler)
-    return CJS_Return(true);
+    return CJS_Return();
 
   pWidgetHandler->ProcessEvent(pEventParam->m_pTarget, pEventParam);
-  return CJS_Return(true);
+  return CJS_Return();
 }
 
 CJS_Return CJX_EventPseudoModel::reset(
@@ -197,14 +197,14 @@ CJS_Return CJX_EventPseudoModel::reset(
     const std::vector<v8::Local<v8::Value>>& params) {
   CFXJSE_Engine* pScriptContext = GetDocument()->GetScriptContext();
   if (!pScriptContext)
-    return CJS_Return(true);
+    return CJS_Return();
 
   CXFA_EventParam* pEventParam = pScriptContext->GetEventParam();
   if (!pEventParam)
-    return CJS_Return(true);
+    return CJS_Return();
 
   pEventParam->Reset();
-  return CJS_Return(true);
+  return CJS_Return();
 }
 
 void CJX_EventPseudoModel::Property(CFXJSE_Value* pValue,
diff --git a/fxjs/xfa/cjx_exclgroup.cpp b/fxjs/xfa/cjx_exclgroup.cpp
index 2b66484073..6e44e56079 100644
--- a/fxjs/xfa/cjx_exclgroup.cpp
+++ b/fxjs/xfa/cjx_exclgroup.cpp
@@ -38,7 +38,7 @@ CJS_Return CJX_ExclGroup::execEvent(
 
   execSingleEventByName(runtime->ToWideString(params[0]).AsStringView(),
                         XFA_Element::ExclGroup);
-  return CJS_Return(true);
+  return CJS_Return();
 }
 
 CJS_Return CJX_ExclGroup::execInitialize(
@@ -51,7 +51,7 @@ CJS_Return CJX_ExclGroup::execInitialize(
   if (pNotify)
     pNotify->ExecEventByDeepFirst(GetXFANode(), XFA_EVENT_Initialize, false,
                                   true);
-  return CJS_Return(true);
+  return CJS_Return();
 }
 
 CJS_Return CJX_ExclGroup::execCalculate(
@@ -64,7 +64,7 @@ CJS_Return CJX_ExclGroup::execCalculate(
   if (pNotify)
     pNotify->ExecEventByDeepFirst(GetXFANode(), XFA_EVENT_Calculate, false,
                                   true);
-  return CJS_Return(true);
+  return CJS_Return();
 }
 
 CJS_Return CJX_ExclGroup::execValidate(
diff --git a/fxjs/xfa/cjx_field.cpp b/fxjs/xfa/cjx_field.cpp
index d3f0280d3f..3beb868f1d 100644
--- a/fxjs/xfa/cjx_field.cpp
+++ b/fxjs/xfa/cjx_field.cpp
@@ -44,7 +44,7 @@ CJS_Return CJX_Field::clearItems(
   CXFA_Node* node = GetXFANode();
   if (node->IsWidgetReady())
     node->DeleteItem(-1, true, false);
-  return CJS_Return(true);
+  return CJS_Return();
 }
 
 CJS_Return CJX_Field::execEvent(
@@ -57,7 +57,7 @@ CJS_Return CJX_Field::execEvent(
   int32_t iRet =
       execSingleEventByName(eventString.AsStringView(), XFA_Element::Field);
   if (eventString != L"validate")
-    return CJS_Return(true);
+    return CJS_Return();
 
   return CJS_Return(runtime->NewBoolean(iRet != XFA_EVENTERROR_Error));
 }
@@ -73,7 +73,7 @@ CJS_Return CJX_Field::execInitialize(
     pNotify->ExecEventByDeepFirst(GetXFANode(), XFA_EVENT_Initialize, false,
                                   false);
   }
-  return CJS_Return(true);
+  return CJS_Return();
 }
 
 CJS_Return CJX_Field::deleteItem(
@@ -84,7 +84,7 @@ CJS_Return CJX_Field::deleteItem(
 
   CXFA_Node* node = GetXFANode();
   if (!node->IsWidgetReady())
-    return CJS_Return(true);
+    return CJS_Return();
 
   bool bValue = node->DeleteItem(runtime->ToInt32(params[0]), true, true);
   return CJS_Return(runtime->NewBoolean(bValue));
@@ -119,7 +119,7 @@ CJS_Return CJX_Field::boundItem(
 
   CXFA_Node* node = GetXFANode();
   if (!node->IsWidgetReady())
-    return CJS_Return(true);
+    return CJS_Return();
 
   WideString value = runtime->ToWideString(params[0]);
   WideString boundValue = node->GetItemValue(value.AsStringView());
@@ -134,7 +134,7 @@ CJS_Return CJX_Field::getItemState(
 
   CXFA_Node* node = GetXFANode();
   if (!node->IsWidgetReady())
-    return CJS_Return(true);
+    return CJS_Return();
 
   int32_t state = node->GetItemState(runtime->ToInt32(params[0]));
   return CJS_Return(runtime->NewBoolean(state != 0));
@@ -151,7 +151,7 @@ CJS_Return CJX_Field::execCalculate(
     pNotify->ExecEventByDeepFirst(GetXFANode(), XFA_EVENT_Calculate, false,
                                   false);
   }
-  return CJS_Return(true);
+  return CJS_Return();
 }
 
 CJS_Return CJX_Field::getDisplayItem(
@@ -183,17 +183,17 @@ CJS_Return CJX_Field::setItemState(
 
   CXFA_Node* node = GetXFANode();
   if (!node->IsWidgetReady())
-    return CJS_Return(true);
+    return CJS_Return();
 
   int32_t iIndex = runtime->ToInt32(params[0]);
   if (runtime->ToInt32(params[1]) != 0) {
     node->SetItemState(iIndex, true, true, true, true);
-    return CJS_Return(true);
+    return CJS_Return();
   }
   if (node->GetItemState(iIndex))
     node->SetItemState(iIndex, false, true, true, true);
 
-  return CJS_Return(true);
+  return CJS_Return();
 }
 
 CJS_Return CJX_Field::addItem(CFX_V8* runtime,
@@ -203,7 +203,7 @@ CJS_Return CJX_Field::addItem(CFX_V8* runtime,
 
   CXFA_Node* node = GetXFANode();
   if (!node->IsWidgetReady())
-    return CJS_Return(true);
+    return CJS_Return();
 
   WideString label;
   if (params.size() >= 1)
@@ -214,7 +214,7 @@ CJS_Return CJX_Field::addItem(CFX_V8* runtime,
     value = runtime->ToWideString(params[1]);
 
   node->InsertItem(label, value, true);
-  return CJS_Return(true);
+  return CJS_Return();
 }
 
 CJS_Return CJX_Field::execValidate(
diff --git a/fxjs/xfa/cjx_form.cpp b/fxjs/xfa/cjx_form.cpp
index fa244b3af6..d1d50ad8f3 100644
--- a/fxjs/xfa/cjx_form.cpp
+++ b/fxjs/xfa/cjx_form.cpp
@@ -59,7 +59,7 @@ CJS_Return CJX_Form::remerge(CFX_V8* runtime,
     return CJS_Return(JSGetStringFromID(JSMessage::kParamError));
 
   GetDocument()->DoDataRemerge(true);
-  return CJS_Return(true);
+  return CJS_Return();
 }
 
 CJS_Return CJX_Form::execInitialize(
@@ -72,7 +72,7 @@ CJS_Return CJX_Form::execInitialize(
   if (pNotify)
     pNotify->ExecEventByDeepFirst(GetXFANode(), XFA_EVENT_Initialize, false,
                                   true);
-  return CJS_Return(true);
+  return CJS_Return();
 }
 
 CJS_Return CJX_Form::recalculate(
@@ -82,19 +82,19 @@ CJS_Return CJX_Form::recalculate(
       GetDocument()->GetScriptContext()->GetEventParam();
   if (pEventParam->m_eType == XFA_EVENT_Calculate ||
       pEventParam->m_eType == XFA_EVENT_InitCalculate) {
-    return CJS_Return(true);
+    return CJS_Return();
   }
   if (params.size() != 1)
     return CJS_Return(JSGetStringFromID(JSMessage::kParamError));
 
   CXFA_FFNotify* pNotify = GetDocument()->GetNotify();
   if (!pNotify || runtime->ToInt32(params[0]) != 0)
-    return CJS_Return(true);
+    return CJS_Return();
 
   pNotify->ExecEventByDeepFirst(GetXFANode(), XFA_EVENT_Calculate, false, true);
   pNotify->ExecEventByDeepFirst(GetXFANode(), XFA_EVENT_Validate, false, true);
   pNotify->ExecEventByDeepFirst(GetXFANode(), XFA_EVENT_Ready, true, true);
-  return CJS_Return(true);
+  return CJS_Return();
 }
 
 CJS_Return CJX_Form::execCalculate(
@@ -107,7 +107,7 @@ CJS_Return CJX_Form::execCalculate(
   if (pNotify)
     pNotify->ExecEventByDeepFirst(GetXFANode(), XFA_EVENT_Calculate, false,
                                   true);
-  return CJS_Return(true);
+  return CJS_Return();
 }
 
 CJS_Return CJX_Form::execValidate(
diff --git a/fxjs/xfa/cjx_hostpseudomodel.cpp b/fxjs/xfa/cjx_hostpseudomodel.cpp
index fe26d3161d..2d9b1bf712 100644
--- a/fxjs/xfa/cjx_hostpseudomodel.cpp
+++ b/fxjs/xfa/cjx_hostpseudomodel.cpp
@@ -243,33 +243,33 @@ CJS_Return CJX_HostPseudoModel::gotoURL(
     CFX_V8* runtime,
     const std::vector<v8::Local<v8::Value>>& params) {
   if (!GetDocument()->GetScriptContext()->IsRunAtClient())
-    return CJS_Return(true);
+    return CJS_Return();
 
   if (params.size() != 1)
     return CJS_Return(JSGetStringFromID(JSMessage::kParamError));
 
   CXFA_FFNotify* pNotify = GetDocument()->GetNotify();
   if (!pNotify)
-    return CJS_Return(true);
+    return CJS_Return();
 
   CXFA_FFDoc* hDoc = pNotify->GetHDOC();
   WideString URL = runtime->ToWideString(params[0]);
   hDoc->GetDocEnvironment()->GotoURL(hDoc, URL);
-  return CJS_Return(true);
+  return CJS_Return();
 }
 
 CJS_Return CJX_HostPseudoModel::openList(
     CFX_V8* runtime,
     const std::vector<v8::Local<v8::Value>>& params) {
   if (!GetDocument()->GetScriptContext()->IsRunAtClient())
-    return CJS_Return(true);
+    return CJS_Return();
 
   if (params.size() != 1)
     return CJS_Return(JSGetStringFromID(JSMessage::kParamError));
 
   CXFA_FFNotify* pNotify = GetDocument()->GetNotify();
   if (!pNotify)
-    return CJS_Return(true);
+    return CJS_Return();
 
   CXFA_Node* pNode = nullptr;
   if (params[0]->IsObject()) {
@@ -278,11 +278,11 @@ CJS_Return CJX_HostPseudoModel::openList(
   } else if (params[0]->IsString()) {
     CFXJSE_Engine* pScriptContext = GetDocument()->GetScriptContext();
     if (!pScriptContext)
-      return CJS_Return(true);
+      return CJS_Return();
 
     CXFA_Object* pObject = pScriptContext->GetThisObject();
     if (!pObject)
-      return CJS_Return(true);
+      return CJS_Return();
 
     uint32_t dwFlag = XFA_RESOLVENODE_Children | XFA_RESOLVENODE_Parent |
                       XFA_RESOLVENODE_Siblings;
@@ -291,24 +291,24 @@ CJS_Return CJX_HostPseudoModel::openList(
         pObject, runtime->ToWideString(params[0]).AsStringView(),
         &resolveNodeRS, dwFlag, nullptr);
     if (!iRet || !resolveNodeRS.objects.front()->IsNode())
-      return CJS_Return(true);
+      return CJS_Return();
 
     pNode = resolveNodeRS.objects.front()->AsNode();
   }
 
   CXFA_LayoutProcessor* pDocLayout = GetDocument()->GetLayoutProcessor();
   if (!pDocLayout)
-    return CJS_Return(true);
+    return CJS_Return();
 
   CXFA_FFWidget* hWidget =
       XFA_GetWidgetFromLayoutItem(pDocLayout->GetLayoutItem(pNode));
   if (!hWidget)
-    return CJS_Return(true);
+    return CJS_Return();
 
   CXFA_FFDoc* hDoc = pNotify->GetHDOC();
   hDoc->GetDocEnvironment()->SetFocusWidget(hDoc, hWidget);
   pNotify->OpenDropDownList(hWidget);
-  return CJS_Return(true);
+  return CJS_Return();
 }
 
 CJS_Return CJX_HostPseudoModel::response(
@@ -319,7 +319,7 @@ CJS_Return CJX_HostPseudoModel::response(
 
   CXFA_FFNotify* pNotify = GetDocument()->GetNotify();
   if (!pNotify)
-    return CJS_Return(true);
+    return CJS_Return();
 
   WideString question;
   if (params.size() >= 1)
@@ -356,7 +356,7 @@ CJS_Return CJX_HostPseudoModel::resetData(
 
   CXFA_FFNotify* pNotify = GetDocument()->GetNotify();
   if (!pNotify)
-    return CJS_Return(true);
+    return CJS_Return();
 
   WideString expression;
   if (params.size() >= 1)
@@ -364,7 +364,7 @@ CJS_Return CJX_HostPseudoModel::resetData(
 
   if (expression.IsEmpty()) {
     pNotify->ResetData(nullptr);
-    return CJS_Return(true);
+    return CJS_Return();
   }
 
   int32_t iStart = 0;
@@ -375,11 +375,11 @@ CJS_Return CJX_HostPseudoModel::resetData(
     iStart = FilterName(expression.AsStringView(), iStart, wsName);
     CFXJSE_Engine* pScriptContext = GetDocument()->GetScriptContext();
     if (!pScriptContext)
-      return CJS_Return(true);
+      return CJS_Return();
 
     CXFA_Object* pObject = pScriptContext->GetThisObject();
     if (!pObject)
-      return CJS_Return(true);
+      return CJS_Return();
 
     uint32_t dwFlag = XFA_RESOLVENODE_Children | XFA_RESOLVENODE_Parent |
                       XFA_RESOLVENODE_Siblings;
@@ -395,42 +395,42 @@ CJS_Return CJX_HostPseudoModel::resetData(
   if (!pNode)
     pNotify->ResetData(nullptr);
 
-  return CJS_Return(true);
+  return CJS_Return();
 }
 
 CJS_Return CJX_HostPseudoModel::beep(
     CFX_V8* runtime,
     const std::vector<v8::Local<v8::Value>>& params) {
   if (!GetDocument()->GetScriptContext()->IsRunAtClient())
-    return CJS_Return(true);
+    return CJS_Return();
 
   if (params.size() > 1)
     return CJS_Return(JSGetStringFromID(JSMessage::kParamError));
 
   CXFA_FFNotify* pNotify = GetDocument()->GetNotify();
   if (!pNotify)
-    return CJS_Return(true);
+    return CJS_Return();
 
   uint32_t dwType = 4;
   if (params.size() >= 1)
     dwType = runtime->ToInt32(params[0]);
 
   pNotify->GetAppProvider()->Beep(dwType);
-  return CJS_Return(true);
+  return CJS_Return();
 }
 
 CJS_Return CJX_HostPseudoModel::setFocus(
     CFX_V8* runtime,
     const std::vector<v8::Local<v8::Value>>& params) {
   if (!GetDocument()->GetScriptContext()->IsRunAtClient())
-    return CJS_Return(true);
+    return CJS_Return();
 
   if (params.size() != 1)
     return CJS_Return(JSGetStringFromID(JSMessage::kParamError));
 
   CXFA_FFNotify* pNotify = GetDocument()->GetNotify();
   if (!pNotify)
-    return CJS_Return(true);
+    return CJS_Return();
 
   CXFA_Node* pNode = nullptr;
   if (params.size() >= 1) {
@@ -440,11 +440,11 @@ CJS_Return CJX_HostPseudoModel::setFocus(
     } else if (params[0]->IsString()) {
       CFXJSE_Engine* pScriptContext = GetDocument()->GetScriptContext();
       if (!pScriptContext)
-        return CJS_Return(true);
+        return CJS_Return();
 
       CXFA_Object* pObject = pScriptContext->GetThisObject();
       if (!pObject)
-        return CJS_Return(true);
+        return CJS_Return();
 
       uint32_t dwFlag = XFA_RESOLVENODE_Children | XFA_RESOLVENODE_Parent |
                         XFA_RESOLVENODE_Siblings;
@@ -453,13 +453,13 @@ CJS_Return CJX_HostPseudoModel::setFocus(
           pObject, runtime->ToWideString(params[0]).AsStringView(),
           &resolveNodeRS, dwFlag, nullptr);
       if (!iRet || !resolveNodeRS.objects.front()->IsNode())
-        return CJS_Return(true);
+        return CJS_Return();
 
       pNode = resolveNodeRS.objects.front()->AsNode();
     }
   }
   pNotify->SetFocusWidgetNode(pNode);
-  return CJS_Return(true);
+  return CJS_Return();
 }
 
 CJS_Return CJX_HostPseudoModel::getFocus(
@@ -467,11 +467,11 @@ CJS_Return CJX_HostPseudoModel::getFocus(
     const std::vector<v8::Local<v8::Value>>& params) {
   CXFA_FFNotify* pNotify = GetDocument()->GetNotify();
   if (!pNotify)
-    return CJS_Return(true);
+    return CJS_Return();
 
   CXFA_Node* pNode = pNotify->GetFocusWidgetNode();
   if (!pNode)
-    return CJS_Return(true);
+    return CJS_Return();
 
   CFXJSE_Value* value =
       GetDocument()->GetScriptContext()->GetJSValueFromMap(pNode);
@@ -485,14 +485,14 @@ CJS_Return CJX_HostPseudoModel::messageBox(
     CFX_V8* runtime,
     const std::vector<v8::Local<v8::Value>>& params) {
   if (!GetDocument()->GetScriptContext()->IsRunAtClient())
-    return CJS_Return(true);
+    return CJS_Return();
 
   if (params.empty() || params.size() > 4)
     return CJS_Return(JSGetStringFromID(JSMessage::kParamError));
 
   CXFA_FFNotify* pNotify = GetDocument()->GetNotify();
   if (!pNotify)
-    return CJS_Return(true);
+    return CJS_Return();
 
   WideString message;
   if (params.size() >= 1)
@@ -531,14 +531,14 @@ CJS_Return CJX_HostPseudoModel::print(
     CFX_V8* runtime,
     const std::vector<v8::Local<v8::Value>>& params) {
   if (!GetDocument()->GetScriptContext()->IsRunAtClient())
-    return CJS_Return(true);
+    return CJS_Return();
 
   if (params.size() != 8)
     return CJS_Return(JSGetStringFromID(JSMessage::kParamError));
 
   CXFA_FFNotify* pNotify = GetDocument()->GetNotify();
   if (!pNotify)
-    return CJS_Return(true);
+    return CJS_Return();
 
   uint32_t dwOptions = 0;
   if (runtime->ToBoolean(params[0]))
@@ -559,7 +559,7 @@ CJS_Return CJX_HostPseudoModel::print(
 
   CXFA_FFDoc* hDoc = pNotify->GetHDOC();
   hDoc->GetDocEnvironment()->Print(hDoc, nStartPage, nEndPage, dwOptions);
-  return CJS_Return(true);
+  return CJS_Return();
 }
 
 CJS_Return CJX_HostPseudoModel::importData(
@@ -568,7 +568,7 @@ CJS_Return CJX_HostPseudoModel::importData(
   if (params.empty() || params.size() > 1)
     return CJS_Return(JSGetStringFromID(JSMessage::kParamError));
 
-  return CJS_Return(true);
+  return CJS_Return();
 }
 
 CJS_Return CJX_HostPseudoModel::exportData(
@@ -579,7 +579,7 @@ CJS_Return CJX_HostPseudoModel::exportData(
 
   CXFA_FFNotify* pNotify = GetDocument()->GetNotify();
   if (!pNotify)
-    return CJS_Return(true);
+    return CJS_Return();
 
   WideString filePath;
   if (params.size() >= 1)
@@ -591,7 +591,7 @@ CJS_Return CJX_HostPseudoModel::exportData(
 
   CXFA_FFDoc* hDoc = pNotify->GetHDOC();
   hDoc->GetDocEnvironment()->ExportData(hDoc, filePath, XDP);
-  return CJS_Return(true);
+  return CJS_Return();
 }
 
 CJS_Return CJX_HostPseudoModel::pageUp(
@@ -599,17 +599,17 @@ CJS_Return CJX_HostPseudoModel::pageUp(
     const std::vector<v8::Local<v8::Value>>& params) {
   CXFA_FFNotify* pNotify = GetDocument()->GetNotify();
   if (!pNotify)
-    return CJS_Return(true);
+    return CJS_Return();
 
   CXFA_FFDoc* hDoc = pNotify->GetHDOC();
   int32_t nCurPage = hDoc->GetDocEnvironment()->GetCurrentPage(hDoc);
   int32_t nNewPage = 0;
   if (nCurPage <= 1)
-    return CJS_Return(true);
+    return CJS_Return();
 
   nNewPage = nCurPage - 1;
   hDoc->GetDocEnvironment()->SetCurrentPage(hDoc, nNewPage);
-  return CJS_Return(true);
+  return CJS_Return();
 }
 
 CJS_Return CJX_HostPseudoModel::pageDown(
@@ -617,13 +617,13 @@ CJS_Return CJX_HostPseudoModel::pageDown(
     const std::vector<v8::Local<v8::Value>>& params) {
   CXFA_FFNotify* pNotify = GetDocument()->GetNotify();
   if (!pNotify)
-    return CJS_Return(true);
+    return CJS_Return();
 
   CXFA_FFDoc* hDoc = pNotify->GetHDOC();
   int32_t nCurPage = hDoc->GetDocEnvironment()->GetCurrentPage(hDoc);
   int32_t nPageCount = hDoc->GetDocEnvironment()->CountPages(hDoc);
   if (!nPageCount || nCurPage == nPageCount)
-    return CJS_Return(true);
+    return CJS_Return();
 
   int32_t nNewPage = 0;
   if (nCurPage >= nPageCount)
@@ -632,5 +632,5 @@ CJS_Return CJX_HostPseudoModel::pageDown(
     nNewPage = nCurPage + 1;
 
   hDoc->GetDocEnvironment()->SetCurrentPage(hDoc, nNewPage);
-  return CJS_Return(true);
+  return CJS_Return();
 }
diff --git a/fxjs/xfa/cjx_instancemanager.cpp b/fxjs/xfa/cjx_instancemanager.cpp
index 081b685efa..f8df62cdbc 100644
--- a/fxjs/xfa/cjx_instancemanager.cpp
+++ b/fxjs/xfa/cjx_instancemanager.cpp
@@ -144,7 +144,7 @@ CJS_Return CJX_InstanceManager::moveInstance(
 
   CXFA_FFNotify* pNotify = GetDocument()->GetNotify();
   if (!pNotify)
-    return CJS_Return(true);
+    return CJS_Return();
 
   CXFA_Node* pToInstance = GetXFANode()->GetItemIfExists(iTo);
   if (pToInstance && pToInstance->GetElementType() == XFA_Element::Subform)
@@ -156,7 +156,7 @@ CJS_Return CJX_InstanceManager::moveInstance(
     pNotify->RunSubformIndexChange(pFromInstance);
   }
 
-  return CJS_Return(true);
+  return CJS_Return();
 }
 
 CJS_Return CJX_InstanceManager::removeInstance(
@@ -196,7 +196,7 @@ CJS_Return CJX_InstanceManager::removeInstance(
     pLayoutPro->AddChangedContainer(
         ToNode(GetDocument()->GetXFAObject(XFA_HASHCODE_Form)));
   }
-  return CJS_Return(true);
+  return CJS_Return();
 }
 
 CJS_Return CJX_InstanceManager::setInstances(
@@ -206,7 +206,7 @@ CJS_Return CJX_InstanceManager::setInstances(
     return CJS_Return(JSGetStringFromID(JSMessage::kParamError));
 
   SetInstances(runtime->ToInt32(params[0]));
-  return CJS_Return(true);
+  return CJS_Return();
 }
 
 CJS_Return CJX_InstanceManager::addInstance(
diff --git a/fxjs/xfa/cjx_layoutpseudomodel.cpp b/fxjs/xfa/cjx_layoutpseudomodel.cpp
index 6a01d2914e..0ae4871d09 100644
--- a/fxjs/xfa/cjx_layoutpseudomodel.cpp
+++ b/fxjs/xfa/cjx_layoutpseudomodel.cpp
@@ -78,7 +78,7 @@ CJS_Return CJX_LayoutPseudoModel::HWXY(
   CXFA_Node* pNode =
       ToNode(static_cast<CFXJSE_Engine*>(runtime)->ToXFAObject(params[0]));
   if (!pNode)
-    return CJS_Return(true);
+    return CJS_Return();
 
   WideString unit(L"pt");
   if (params.size() >= 2) {
@@ -90,11 +90,11 @@ CJS_Return CJX_LayoutPseudoModel::HWXY(
 
   CXFA_LayoutProcessor* pDocLayout = GetDocument()->GetLayoutProcessor();
   if (!pDocLayout)
-    return CJS_Return(true);
+    return CJS_Return();
 
   CXFA_LayoutItem* pLayoutItem = pDocLayout->GetLayoutItem(pNode);
   if (!pLayoutItem)
-    return CJS_Return(true);
+    return CJS_Return();
 
   while (iIndex > 0 && pLayoutItem) {
     pLayoutItem = pLayoutItem->GetNext();
@@ -154,7 +154,7 @@ CJS_Return CJX_LayoutPseudoModel::NumberedPageCount(CFX_V8* runtime,
                                                     bool bNumbered) {
   CXFA_LayoutProcessor* pDocLayout = GetDocument()->GetLayoutProcessor();
   if (!pDocLayout)
-    return CJS_Return(true);
+    return CJS_Return();
 
   int32_t iPageCount = 0;
   int32_t iPageNum = pDocLayout->CountPages();
@@ -189,11 +189,11 @@ CJS_Return CJX_LayoutPseudoModel::pageSpan(
   CXFA_Node* pNode =
       ToNode(static_cast<CFXJSE_Engine*>(runtime)->ToXFAObject(params[0]));
   if (!pNode)
-    return CJS_Return(true);
+    return CJS_Return();
 
   CXFA_LayoutProcessor* pDocLayout = GetDocument()->GetLayoutProcessor();
   if (!pDocLayout)
-    return CJS_Return(true);
+    return CJS_Return();
 
   CXFA_LayoutItem* pLayoutItem = pDocLayout->GetLayoutItem(pNode);
   if (!pLayoutItem)
@@ -365,11 +365,11 @@ CJS_Return CJX_LayoutPseudoModel::pageContent(
 
   CXFA_FFNotify* pNotify = GetDocument()->GetNotify();
   if (!pNotify)
-    return CJS_Return(true);
+    return CJS_Return();
 
   CXFA_LayoutProcessor* pDocLayout = GetDocument()->GetLayoutProcessor();
   if (!pDocLayout)
-    return CJS_Return(true);
+    return CJS_Return();
 
   auto pArrayNodeList = pdfium::MakeUnique<CXFA_ArrayNodeList>(GetDocument());
   pArrayNodeList->SetArrayNodeList(
@@ -411,7 +411,7 @@ CJS_Return CJX_LayoutPseudoModel::relayout(
     pLayoutProcessor->AddChangedContainer(pContentRootNode);
 
   pLayoutProcessor->SetForceReLayout(true);
-  return CJS_Return(true);
+  return CJS_Return();
 }
 
 CJS_Return CJX_LayoutPseudoModel::absPageSpan(
@@ -445,7 +445,7 @@ CJS_Return CJX_LayoutPseudoModel::sheet(
 CJS_Return CJX_LayoutPseudoModel::relayoutPageArea(
     CFX_V8* runtime,
     const std::vector<v8::Local<v8::Value>>& params) {
-  return CJS_Return(true);
+  return CJS_Return();
 }
 
 CJS_Return CJX_LayoutPseudoModel::sheetCount(
@@ -474,7 +474,7 @@ CJS_Return CJX_LayoutPseudoModel::PageInternals(
 
   CXFA_LayoutProcessor* pDocLayout = GetDocument()->GetLayoutProcessor();
   if (!pDocLayout)
-    return CJS_Return(true);
+    return CJS_Return();
 
   CXFA_LayoutItem* pLayoutItem = pDocLayout->GetLayoutItem(pNode);
   if (!pLayoutItem)
diff --git a/fxjs/xfa/cjx_list.cpp b/fxjs/xfa/cjx_list.cpp
index 4340e3b089..b6ac47ec79 100644
--- a/fxjs/xfa/cjx_list.cpp
+++ b/fxjs/xfa/cjx_list.cpp
@@ -42,7 +42,7 @@ CJS_Return CJX_List::append(CFX_V8* runtime,
     return CJS_Return(JSGetStringFromID(JSMessage::kValueError));
 
   GetXFAList()->Append(pNode);
-  return CJS_Return(true);
+  return CJS_Return();
 }
 
 CJS_Return CJX_List::insert(CFX_V8* runtime,
@@ -58,7 +58,7 @@ CJS_Return CJX_List::insert(CFX_V8* runtime,
   auto* pBeforeNode =
       ToNode(static_cast<CFXJSE_Engine*>(runtime)->ToXFAObject(params[1]));
   GetXFAList()->Insert(pNewNode, pBeforeNode);
-  return CJS_Return(true);
+  return CJS_Return();
 }
 
 CJS_Return CJX_List::remove(CFX_V8* runtime,
@@ -72,7 +72,7 @@ CJS_Return CJX_List::remove(CFX_V8* runtime,
     return CJS_Return(JSGetStringFromID(JSMessage::kValueError));
 
   GetXFAList()->Remove(pNode);
-  return CJS_Return(true);
+  return CJS_Return();
 }
 
 CJS_Return CJX_List::item(CFX_V8* runtime,
diff --git a/fxjs/xfa/cjx_logpseudomodel.cpp b/fxjs/xfa/cjx_logpseudomodel.cpp
index 18093f5263..93772ed03d 100644
--- a/fxjs/xfa/cjx_logpseudomodel.cpp
+++ b/fxjs/xfa/cjx_logpseudomodel.cpp
@@ -35,29 +35,29 @@ CJS_Return CJX_LogPseudoModel::message(
   //   fprintf(stderr, "  %ls\n", WideString::FromUTF8(*str).c_str());
   // }
 
-  return CJS_Return(true);
+  return CJS_Return();
 }
 
 CJS_Return CJX_LogPseudoModel::traceEnabled(
     CFX_V8* runtime,
     const std::vector<v8::Local<v8::Value>>& params) {
-  return CJS_Return(true);
+  return CJS_Return();
 }
 
 CJS_Return CJX_LogPseudoModel::traceActivate(
     CFX_V8* runtime,
     const std::vector<v8::Local<v8::Value>>& params) {
-  return CJS_Return(true);
+  return CJS_Return();
 }
 
 CJS_Return CJX_LogPseudoModel::traceDeactivate(
     CFX_V8* runtime,
     const std::vector<v8::Local<v8::Value>>& params) {
-  return CJS_Return(true);
+  return CJS_Return();
 }
 
 CJS_Return CJX_LogPseudoModel::trace(
     CFX_V8* runtime,
     const std::vector<v8::Local<v8::Value>>& params) {
-  return CJS_Return(true);
+  return CJS_Return();
 }
diff --git a/fxjs/xfa/cjx_model.cpp b/fxjs/xfa/cjx_model.cpp
index 857d6a4b01..688b30350a 100644
--- a/fxjs/xfa/cjx_model.cpp
+++ b/fxjs/xfa/cjx_model.cpp
@@ -28,7 +28,7 @@ CJX_Model::~CJX_Model() {}
 CJS_Return CJX_Model::clearErrorList(
     CFX_V8* runtime,
     const std::vector<v8::Local<v8::Value>>& params) {
-  return CJS_Return(true);
+  return CJS_Return();
 }
 
 CJS_Return CJX_Model::createNode(
diff --git a/fxjs/xfa/cjx_node.cpp b/fxjs/xfa/cjx_node.cpp
index a07aa4cb2c..7c472db6c9 100644
--- a/fxjs/xfa/cjx_node.cpp
+++ b/fxjs/xfa/cjx_node.cpp
@@ -117,7 +117,7 @@ CJS_Return CJX_Node::applyXSL(CFX_V8* runtime,
     return CJS_Return(JSGetStringFromID(JSMessage::kParamError));
 
   // TODO(weili): check whether we need to implement this, pdfium:501.
-  return CJS_Return(true);
+  return CJS_Return();
 }
 
 CJS_Return CJX_Node::assignNode(
@@ -127,7 +127,7 @@ CJS_Return CJX_Node::assignNode(
     return CJS_Return(JSGetStringFromID(JSMessage::kParamError));
 
   // TODO(weili): check whether we need to implement this, pdfium:501.
-  return CJS_Return(true);
+  return CJS_Return();
 }
 
 CJS_Return CJX_Node::clone(CFX_V8* runtime,
@@ -206,7 +206,7 @@ CJS_Return CJX_Node::loadXML(CFX_V8* runtime,
 
   ByteString expression = runtime->ToByteString(params[0]);
   if (expression.IsEmpty())
-    return CJS_Return(true);
+    return CJS_Return();
 
   bool bIgnoreRoot = true;
   if (params.size() >= 2)
@@ -218,11 +218,11 @@ CJS_Return CJX_Node::loadXML(CFX_V8* runtime,
 
   auto pParser = pdfium::MakeUnique<CXFA_DocumentParser>(GetDocument());
   if (!pParser)
-    return CJS_Return(true);
+    return CJS_Return();
 
   CFX_XMLNode* pXMLNode = pParser->ParseXMLData(expression);
   if (!pXMLNode)
-    return CJS_Return(true);
+    return CJS_Return();
 
   if (bIgnoreRoot &&
       (pXMLNode->GetType() != FX_XMLNODE_Element ||
@@ -278,7 +278,7 @@ CJS_Return CJX_Node::loadXML(CFX_V8* runtime,
   pParser->ConstructXFANode(pFakeRoot, pFakeXMLRoot);
   pFakeRoot = pParser->GetRootNode();
   if (!pFakeRoot)
-    return CJS_Return(true);
+    return CJS_Return();
 
   if (bOverwrite) {
     CXFA_Node* pChild = GetXFANode()->GetFirstChild();
@@ -326,14 +326,14 @@ CJS_Return CJX_Node::loadXML(CFX_V8* runtime,
   }
   pFakeRoot->SetFlag(XFA_NodeFlag_HasRemovedChildren);
 
-  return CJS_Return(true);
+  return CJS_Return();
 }
 
 CJS_Return CJX_Node::saveFilteredXML(
     CFX_V8* runtime,
     const std::vector<v8::Local<v8::Value>>& params) {
   // TODO(weili): Check whether we need to implement this, pdfium:501.
-  return CJS_Return(true);
+  return CJS_Return();
 }
 
 CJS_Return CJX_Node::saveXML(CFX_V8* runtime,
@@ -383,7 +383,7 @@ CJS_Return CJX_Node::setAttribute(
   WideString attributeValue = runtime->ToWideString(params[0]);
   WideString attribute = runtime->ToWideString(params[1]);
   SetAttribute(attribute.AsStringView(), attributeValue.AsStringView(), true);
-  return CJS_Return(true);
+  return CJS_Return();
 }
 
 CJS_Return CJX_Node::setElement(
@@ -393,7 +393,7 @@ CJS_Return CJX_Node::setElement(
     return CJS_Return(JSGetStringFromID(JSMessage::kParamError));
 
   // TODO(weili): check whether we need to implement this, pdfium:501.
-  return CJS_Return(true);
+  return CJS_Return();
 }
 
 void CJX_Node::id(CFXJSE_Value* pValue,
diff --git a/fxjs/xfa/cjx_object.cpp b/fxjs/xfa/cjx_object.cpp
index ba914221bd..d357c56091 100644
--- a/fxjs/xfa/cjx_object.cpp
+++ b/fxjs/xfa/cjx_object.cpp
@@ -172,7 +172,8 @@ CJS_Return CJX_Object::RunMethod(
     const std::vector<v8::Local<v8::Value>>& params) {
   auto it = method_specs_.find(func.UTF8Encode());
   if (it == method_specs_.end())
-    return CJS_Return(false);
+    return CJS_Return(JSMessage::kUnknownMethod);
+
   return it->second(this, GetXFAObject()->GetDocument()->GetScriptContext(),
                     params);
 }
diff --git a/fxjs/xfa/cjx_signaturepseudomodel.cpp b/fxjs/xfa/cjx_signaturepseudomodel.cpp
index 304177884b..0e4d560da3 100644
--- a/fxjs/xfa/cjx_signaturepseudomodel.cpp
+++ b/fxjs/xfa/cjx_signaturepseudomodel.cpp
@@ -47,7 +47,7 @@ CJS_Return CJX_SignaturePseudoModel::enumerate(
     const std::vector<v8::Local<v8::Value>>& params) {
   if (!params.empty())
     return CJS_Return(JSGetStringFromID(JSMessage::kParamError));
-  return CJS_Return(true);
+  return CJS_Return();
 }
 
 CJS_Return CJX_SignaturePseudoModel::clear(
diff --git a/fxjs/xfa/cjx_source.cpp b/fxjs/xfa/cjx_source.cpp
index 7576e7718d..98772b5acf 100644
--- a/fxjs/xfa/cjx_source.cpp
+++ b/fxjs/xfa/cjx_source.cpp
@@ -41,7 +41,7 @@ CJS_Return CJX_Source::next(CFX_V8* runtime,
                             const std::vector<v8::Local<v8::Value>>& params) {
   if (!params.empty())
     return CJS_Return(JSGetStringFromID(JSMessage::kParamError));
-  return CJS_Return(true);
+  return CJS_Return();
 }
 
 CJS_Return CJX_Source::cancelBatch(
@@ -49,14 +49,14 @@ CJS_Return CJX_Source::cancelBatch(
     const std::vector<v8::Local<v8::Value>>& params) {
   if (!params.empty())
     return CJS_Return(JSGetStringFromID(JSMessage::kParamError));
-  return CJS_Return(true);
+  return CJS_Return();
 }
 
 CJS_Return CJX_Source::first(CFX_V8* runtime,
                              const std::vector<v8::Local<v8::Value>>& params) {
   if (!params.empty())
     return CJS_Return(JSGetStringFromID(JSMessage::kParamError));
-  return CJS_Return(true);
+  return CJS_Return();
 }
 
 CJS_Return CJX_Source::updateBatch(
@@ -64,7 +64,7 @@ CJS_Return CJX_Source::updateBatch(
     const std::vector<v8::Local<v8::Value>>& params) {
   if (!params.empty())
     return CJS_Return(JSGetStringFromID(JSMessage::kParamError));
-  return CJS_Return(true);
+  return CJS_Return();
 }
 
 CJS_Return CJX_Source::previous(
@@ -72,42 +72,42 @@ CJS_Return CJX_Source::previous(
     const std::vector<v8::Local<v8::Value>>& params) {
   if (!params.empty())
     return CJS_Return(JSGetStringFromID(JSMessage::kParamError));
-  return CJS_Return(true);
+  return CJS_Return();
 }
 
 CJS_Return CJX_Source::isBOF(CFX_V8* runtime,
                              const std::vector<v8::Local<v8::Value>>& params) {
   if (!params.empty())
     return CJS_Return(JSGetStringFromID(JSMessage::kParamError));
-  return CJS_Return(true);
+  return CJS_Return();
 }
 
 CJS_Return CJX_Source::isEOF(CFX_V8* runtime,
                              const std::vector<v8::Local<v8::Value>>& params) {
   if (!params.empty())
     return CJS_Return(JSGetStringFromID(JSMessage::kParamError));
-  return CJS_Return(true);
+  return CJS_Return();
 }
 
 CJS_Return CJX_Source::cancel(CFX_V8* runtime,
                               const std::vector<v8::Local<v8::Value>>& params) {
   if (!params.empty())
     return CJS_Return(JSGetStringFromID(JSMessage::kParamError));
-  return CJS_Return(true);
+  return CJS_Return();
 }
 
 CJS_Return CJX_Source::update(CFX_V8* runtime,
                               const std::vector<v8::Local<v8::Value>>& params) {
   if (!params.empty())
     return CJS_Return(JSGetStringFromID(JSMessage::kParamError));
-  return CJS_Return(true);
+  return CJS_Return();
 }
 
 CJS_Return CJX_Source::open(CFX_V8* runtime,
                             const std::vector<v8::Local<v8::Value>>& params) {
   if (!params.empty())
     return CJS_Return(JSGetStringFromID(JSMessage::kParamError));
-  return CJS_Return(true);
+  return CJS_Return();
 }
 
 CJS_Return CJX_Source::deleteItem(
@@ -115,14 +115,14 @@ CJS_Return CJX_Source::deleteItem(
     const std::vector<v8::Local<v8::Value>>& params) {
   if (!params.empty())
     return CJS_Return(JSGetStringFromID(JSMessage::kParamError));
-  return CJS_Return(true);
+  return CJS_Return();
 }
 
 CJS_Return CJX_Source::addNew(CFX_V8* runtime,
                               const std::vector<v8::Local<v8::Value>>& params) {
   if (!params.empty())
     return CJS_Return(JSGetStringFromID(JSMessage::kParamError));
-  return CJS_Return(true);
+  return CJS_Return();
 }
 
 CJS_Return CJX_Source::requery(
@@ -130,28 +130,28 @@ CJS_Return CJX_Source::requery(
     const std::vector<v8::Local<v8::Value>>& params) {
   if (!params.empty())
     return CJS_Return(JSGetStringFromID(JSMessage::kParamError));
-  return CJS_Return(true);
+  return CJS_Return();
 }
 
 CJS_Return CJX_Source::resync(CFX_V8* runtime,
                               const std::vector<v8::Local<v8::Value>>& params) {
   if (!params.empty())
     return CJS_Return(JSGetStringFromID(JSMessage::kParamError));
-  return CJS_Return(true);
+  return CJS_Return();
 }
 
 CJS_Return CJX_Source::close(CFX_V8* runtime,
                              const std::vector<v8::Local<v8::Value>>& params) {
   if (!params.empty())
     return CJS_Return(JSGetStringFromID(JSMessage::kParamError));
-  return CJS_Return(true);
+  return CJS_Return();
 }
 
 CJS_Return CJX_Source::last(CFX_V8* runtime,
                             const std::vector<v8::Local<v8::Value>>& params) {
   if (!params.empty())
     return CJS_Return(JSGetStringFromID(JSMessage::kParamError));
-  return CJS_Return(true);
+  return CJS_Return();
 }
 
 CJS_Return CJX_Source::hasDataChanged(
@@ -159,7 +159,7 @@ CJS_Return CJX_Source::hasDataChanged(
     const std::vector<v8::Local<v8::Value>>& params) {
   if (!params.empty())
     return CJS_Return(JSGetStringFromID(JSMessage::kParamError));
-  return CJS_Return(true);
+  return CJS_Return();
 }
 
 void CJX_Source::db(CFXJSE_Value* pValue,
diff --git a/fxjs/xfa/cjx_subform.cpp b/fxjs/xfa/cjx_subform.cpp
index 52f08655ca..042bd85119 100644
--- a/fxjs/xfa/cjx_subform.cpp
+++ b/fxjs/xfa/cjx_subform.cpp
@@ -36,7 +36,7 @@ CJS_Return CJX_Subform::execEvent(
 
   execSingleEventByName(runtime->ToWideString(params[0]).AsStringView(),
                         XFA_Element::Subform);
-  return CJS_Return(true);
+  return CJS_Return();
 }
 
 CJS_Return CJX_Subform::execInitialize(
@@ -49,7 +49,7 @@ CJS_Return CJX_Subform::execInitialize(
   if (pNotify)
     pNotify->ExecEventByDeepFirst(GetXFANode(), XFA_EVENT_Initialize, false,
                                   true);
-  return CJS_Return(true);
+  return CJS_Return();
 }
 
 CJS_Return CJX_Subform::execCalculate(
@@ -62,7 +62,7 @@ CJS_Return CJX_Subform::execCalculate(
   if (pNotify)
     pNotify->ExecEventByDeepFirst(GetXFANode(), XFA_EVENT_Calculate, false,
                                   true);
-  return CJS_Return(true);
+  return CJS_Return();
 }
 
 CJS_Return CJX_Subform::execValidate(
diff --git a/fxjs/xfa/cjx_template.cpp b/fxjs/xfa/cjx_template.cpp
index 6612a7c5c2..0b9c3b2472 100644
--- a/fxjs/xfa/cjx_template.cpp
+++ b/fxjs/xfa/cjx_template.cpp
@@ -42,7 +42,7 @@ CJS_Return CJX_Template::remerge(
     return CJS_Return(JSGetStringFromID(JSMessage::kParamError));
 
   GetDocument()->DoDataRemerge(true);
-  return CJS_Return(true);
+  return CJS_Return();
 }
 
 CJS_Return CJX_Template::execInitialize(
diff --git a/fxjs/xfa/cjx_tree.cpp b/fxjs/xfa/cjx_tree.cpp
index 219953d1d4..442a82d1e6 100644
--- a/fxjs/xfa/cjx_tree.cpp
+++ b/fxjs/xfa/cjx_tree.cpp
@@ -38,7 +38,7 @@ CJS_Return CJX_Tree::resolveNode(
   WideString expression = runtime->ToWideString(params[0]);
   CFXJSE_Engine* pScriptContext = GetDocument()->GetScriptContext();
   if (!pScriptContext)
-    return CJS_Return(true);
+    return CJS_Return();
 
   CXFA_Object* refNode = GetXFAObject();
   if (refNode->GetElementType() == XFA_Element::Xfa)
@@ -90,7 +90,7 @@ CJS_Return CJX_Tree::resolveNodes(
 
   CFXJSE_Engine* pScriptContext = GetDocument()->GetScriptContext();
   if (!pScriptContext)
-    return CJS_Return(true);
+    return CJS_Return();
 
   auto pValue = pdfium::MakeUnique<CFXJSE_Value>(pScriptContext->GetIsolate());
   ResolveNodeList(pValue.get(), runtime->ToWideString(params[0]),
diff --git a/fxjs/xfa/cjx_treelist.cpp b/fxjs/xfa/cjx_treelist.cpp
index 904e09370f..b608734e3c 100644
--- a/fxjs/xfa/cjx_treelist.cpp
+++ b/fxjs/xfa/cjx_treelist.cpp
@@ -37,7 +37,7 @@ CJS_Return CJX_TreeList::namedItem(
   CXFA_Node* pNode = GetXFATreeList()->NamedItem(
       runtime->ToWideString(params[0]).AsStringView());
   if (!pNode)
-    return CJS_Return(true);
+    return CJS_Return();
 
   CFXJSE_Value* value =
       GetDocument()->GetScriptContext()->GetJSValueFromMap(pNode);