Convert TryNamespace to optional

This CL changes CJX_Node::TryNamespace to return a pdfium::Optional
instead of a bool with an out parameter.

Change-Id: I50ccb3544179108d156d763c25e03abab4306c19
Reviewed-on: https://pdfium-review.googlesource.com/18551
Commit-Queue: dsinclair <dsinclair@chromium.org>
Reviewed-by: Tom Sepez <tsepez@chromium.org>

5 files changed, 47 insertions, 45 deletions

diff --git a/fxjs/cjx_node.cpp b/fxjs/cjx_node.cpp
index ac93397b77..17662dada6 100644
--- a/fxjs/cjx_node.cpp
+++ b/fxjs/cjx_node.cpp
@@ -930,10 +930,8 @@ void CJX_Node::Script_NodeClass_Ns(CFXJSE_Value* pValue,
     ThrowInvalidPropertyException();
     return;
   }
-
-  WideString wsNameSpace;
-  TryNamespace(wsNameSpace);
-  pValue->SetString(wsNameSpace.UTF8Encode().AsStringView());
+  pValue->SetString(
+      TryNamespace().value_or(WideString()).UTF8Encode().AsStringView());
 }
 
 void CJX_Node::Script_NodeClass_Model(CFXJSE_Value* pValue,
@@ -1016,11 +1014,11 @@ void CJX_Node::Script_ModelClass_IsCompatibleNS(CFXJSE_Arguments* pArguments) {
     wsNameSpace = WideString::FromUTF8(bsNameSpace.AsStringView());
   }
 
-  WideString wsNodeNameSpace;
-  TryNamespace(wsNodeNameSpace);
   CFXJSE_Value* pValue = pArguments->GetReturnValue();
-  if (pValue)
-    pValue->SetBoolean(wsNodeNameSpace == wsNameSpace);
+  if (!pValue)
+    return;
+
+  pValue->SetBoolean(TryNamespace().value_or(WideString()) == wsNameSpace);
 }
 
 void CJX_Node::Script_ModelClass_Context(CFXJSE_Value* pValue,
@@ -3571,35 +3569,34 @@ pdfium::Optional<WideString> CJX_Node::TryContent(bool bScriptModify,
   return {};
 }
 
-bool CJX_Node::TryNamespace(WideString& wsNamespace) {
-  wsNamespace.clear();
+pdfium::Optional<WideString> CJX_Node::TryNamespace() {
   if (GetXFANode()->IsModelNode() ||
       GetXFANode()->GetElementType() == XFA_Element::Packet) {
     CFX_XMLNode* pXMLNode = GetXFANode()->GetXMLMappingNode();
     if (!pXMLNode || pXMLNode->GetType() != FX_XMLNODE_Element)
-      return false;
+      return {};
 
-    wsNamespace = static_cast<CFX_XMLElement*>(pXMLNode)->GetNamespaceURI();
-    return true;
+    return {static_cast<CFX_XMLElement*>(pXMLNode)->GetNamespaceURI()};
   }
 
   if (GetXFANode()->GetPacketID() != XFA_XDPPACKET_Datasets)
-    return GetXFANode()->GetModelNode()->JSNode()->TryNamespace(wsNamespace);
+    return GetXFANode()->GetModelNode()->JSNode()->TryNamespace();
 
   CFX_XMLNode* pXMLNode = GetXFANode()->GetXMLMappingNode();
-  if (!pXMLNode)
-    return false;
-  if (pXMLNode->GetType() != FX_XMLNODE_Element)
-    return true;
+  if (!pXMLNode || pXMLNode->GetType() != FX_XMLNODE_Element)
+    return {};
 
   if (GetXFANode()->GetElementType() == XFA_Element::DataValue &&
       GetEnum(XFA_Attribute::Contains) == XFA_ATTRIBUTEENUM_MetaData) {
-    return XFA_FDEExtension_ResolveNamespaceQualifier(
+    WideString wsNamespace;
+    bool ret = XFA_FDEExtension_ResolveNamespaceQualifier(
         static_cast<CFX_XMLElement*>(pXMLNode),
         GetCData(XFA_Attribute::QualifiedName), &wsNamespace);
+    if (!ret)
+      return {};
+    return {wsNamespace};
   }
-  wsNamespace = static_cast<CFX_XMLElement*>(pXMLNode)->GetNamespaceURI();
-  return true;
+  return {static_cast<CFX_XMLElement*>(pXMLNode)->GetNamespaceURI()};
 }
 
 CXFA_Node* CJX_Node::GetProperty(int32_t index,
diff --git a/fxjs/cjx_node.h b/fxjs/cjx_node.h
index cb6b6867fd..686c54c164 100644
--- a/fxjs/cjx_node.h
+++ b/fxjs/cjx_node.h
@@ -108,7 +108,7 @@ class CJX_Node : public CJX_Object {
                  XFA_MAPDATABLOCKCALLBACKINFO* pCallbackInfo);
   void* GetObject(XFA_Attribute eAttr);
 
-  bool TryNamespace(WideString& wsNamespace);
+  pdfium::Optional<WideString> TryNamespace();
 
   void MergeAllData(CXFA_Node* pDstModule);
 
diff --git a/xfa/fxfa/parser/cxfa_dataexporter.cpp b/xfa/fxfa/parser/cxfa_dataexporter.cpp
index f7715dc374..c86a7f7d51 100644
--- a/xfa/fxfa/parser/cxfa_dataexporter.cpp
+++ b/xfa/fxfa/parser/cxfa_dataexporter.cpp
@@ -152,12 +152,13 @@ void RecognizeXFAVersionNumber(CXFA_Node* pTemplateRoot,
   if (!pTemplateRoot)
     return;
 
-  WideString wsTemplateNS;
-  if (!pTemplateRoot->JSNode()->TryNamespace(wsTemplateNS))
+  pdfium::Optional<WideString> templateNS =
+      pTemplateRoot->JSNode()->TryNamespace();
+  if (!templateNS)
     return;
 
   XFA_VERSION eVersion =
-      pTemplateRoot->GetDocument()->RecognizeXFAVersionNumber(wsTemplateNS);
+      pTemplateRoot->GetDocument()->RecognizeXFAVersionNumber(*templateNS);
   if (eVersion == XFA_VERSION_UNKNOWN)
     eVersion = XFA_VERSION_DEFAULT;
 
diff --git a/xfa/fxfa/parser/cxfa_document.cpp b/xfa/fxfa/parser/cxfa_document.cpp
index 82a71dea28..44fc9089c1 100644
--- a/xfa/fxfa/parser/cxfa_document.cpp
+++ b/xfa/fxfa/parser/cxfa_document.cpp
@@ -151,14 +151,16 @@ CXFA_Object* CXFA_Document::GetXFAObject(XFA_HashCode dwNodeNameHash) {
         if (pDatasetsChild->GetNameHash() != XFA_HASHCODE_Data)
           continue;
 
-        WideString wsNamespaceURI;
-        if (!pDatasetsChild->JSNode()->TryNamespace(wsNamespaceURI))
+        pdfium::Optional<WideString> namespaceURI =
+            pDatasetsChild->JSNode()->TryNamespace();
+        if (!namespaceURI)
           continue;
 
-        WideString wsDatasetsURI;
-        if (!pDatasetsNode->JSNode()->TryNamespace(wsDatasetsURI))
+        pdfium::Optional<WideString> datasetsURI =
+            pDatasetsNode->JSNode()->TryNamespace();
+        if (!datasetsURI)
           continue;
-        if (wsNamespaceURI == wsDatasetsURI)
+        if (*namespaceURI == *datasetsURI)
           return pDatasetsChild;
       }
       return nullptr;
diff --git a/xfa/fxfa/parser/xfa_document_datamerger_imp.cpp b/xfa/fxfa/parser/xfa_document_datamerger_imp.cpp
index 4cf7601531..89a6500fa6 100644
--- a/xfa/fxfa/parser/xfa_document_datamerger_imp.cpp
+++ b/xfa/fxfa/parser/xfa_document_datamerger_imp.cpp
@@ -1052,12 +1052,11 @@ CXFA_Node* MaybeCreateDataNode(CXFA_Document* pDocument,
       if (pDDGroupNode->GetElementType() != XFA_Element::DataGroup)
         continue;
 
-      WideString wsNamespace;
-      if (!pDDGroupNode->JSNode()->TryNamespace(wsNamespace) ||
-          wsNamespace != L"http://ns.adobe.com/data-description/") {
+      pdfium::Optional<WideString> ns = pDDGroupNode->JSNode()->TryNamespace();
+      if (!ns || *ns != L"http://ns.adobe.com/data-description/")
         continue;
-      }
     }
+
     CXFA_Node* pDDNode =
         pDDGroupNode->GetFirstChildByName(wsName.AsStringView());
     if (!pDDNode)
@@ -1231,12 +1230,12 @@ void UpdateDataRelation(CXFA_Node* pDataNode, CXFA_Node* pDataDescriptionNode) {
         if (pDDGroupNode->GetElementType() != XFA_Element::DataGroup)
           continue;
 
-        WideString wsNamespace;
-        if (!pDDGroupNode->JSNode()->TryNamespace(wsNamespace) ||
-            wsNamespace != L"http://ns.adobe.com/data-description/") {
+        pdfium::Optional<WideString> ns =
+            pDDGroupNode->JSNode()->TryNamespace();
+        if (!ns || *ns != L"http://ns.adobe.com/data-description/")
           continue;
-        }
       }
+
       CXFA_Node* pDDNode = pDDGroupNode->GetFirstChildByName(dwNameHash);
       if (!pDDNode)
         continue;
@@ -1398,8 +1397,8 @@ void CXFA_Document::DoDataMerge() {
     pDatasetsRoot->SetXMLMappingNode(pDatasetsXMLNode);
   }
   CXFA_Node *pDataRoot = nullptr, *pDDRoot = nullptr;
-  WideString wsDatasetsURI;
-  pDatasetsRoot->JSNode()->TryNamespace(wsDatasetsURI);
+  WideString wsDatasetsURI =
+      pDatasetsRoot->JSNode()->TryNamespace().value_or(WideString());
   for (CXFA_Node* pChildNode =
            pDatasetsRoot->GetNodeItem(XFA_NODEITEM_FirstChild);
        pChildNode;
@@ -1407,16 +1406,19 @@ void CXFA_Document::DoDataMerge() {
     if (pChildNode->GetElementType() != XFA_Element::DataGroup)
       continue;
 
-    WideString wsNamespaceURI;
     if (!pDDRoot && pChildNode->GetNameHash() == XFA_HASHCODE_DataDescription) {
-      if (!pChildNode->JSNode()->TryNamespace(wsNamespaceURI))
+      pdfium::Optional<WideString> namespaceURI =
+          pChildNode->JSNode()->TryNamespace();
+      if (!namespaceURI)
         continue;
-      if (wsNamespaceURI == L"http://ns.adobe.com/data-description/")
+      if (*namespaceURI == L"http://ns.adobe.com/data-description/")
         pDDRoot = pChildNode;
     } else if (!pDataRoot && pChildNode->GetNameHash() == XFA_HASHCODE_Data) {
-      if (!pChildNode->JSNode()->TryNamespace(wsNamespaceURI))
+      pdfium::Optional<WideString> namespaceURI =
+          pChildNode->JSNode()->TryNamespace();
+      if (!namespaceURI)
         continue;
-      if (wsNamespaceURI == wsDatasetsURI)
+      if (*namespaceURI == wsDatasetsURI)
         pDataRoot = pChildNode;
     }
     if (pDataRoot && pDDRoot)