Use moar ToXMLElement() in place of static_cast<>.

Introduces checks in a few new places, but mainly just consolidates
checking/casting logic.

Change-Id: I634a03060d254db099972c6978249992367e146c
Reviewed-on: https://pdfium-review.googlesource.com/38900
Commit-Queue: Tom Sepez <tsepez@chromium.org>
Reviewed-by: Lei Zhang <thestig@chromium.org>

2 files changed, 32 insertions, 35 deletions

diff --git a/fxjs/xfa/cjx_object.cpp b/fxjs/xfa/cjx_object.cpp
index 1c0454d425..6984c3a998 100644
--- a/fxjs/xfa/cjx_object.cpp
+++ b/fxjs/xfa/cjx_object.cpp
@@ -806,30 +806,31 @@ Optional<WideString> CJX_Object::TryNamespace() {
   if (ToNode(GetXFAObject())->IsModelNode() ||
       ToNode(GetXFAObject())->GetElementType() == XFA_Element::Packet) {
     CFX_XMLNode* pXMLNode = ToNode(GetXFAObject())->GetXMLMappingNode();
-    if (!pXMLNode || pXMLNode->GetType() != FX_XMLNODE_Element)
+    CFX_XMLElement* element = ToXMLElement(pXMLNode);
+    if (!element)
       return {};
 
-    return {static_cast<CFX_XMLElement*>(pXMLNode)->GetNamespaceURI()};
+    return {element->GetNamespaceURI()};
   }
 
   if (ToNode(GetXFAObject())->GetPacketType() != XFA_PacketType::Datasets)
     return ToNode(GetXFAObject())->GetModelNode()->JSObject()->TryNamespace();
 
   CFX_XMLNode* pXMLNode = ToNode(GetXFAObject())->GetXMLMappingNode();
-  if (!pXMLNode || pXMLNode->GetType() != FX_XMLNODE_Element)
+  CFX_XMLElement* element = ToXMLElement(pXMLNode);
+  if (!element)
     return {};
 
   if (ToNode(GetXFAObject())->GetElementType() == XFA_Element::DataValue &&
       GetEnum(XFA_Attribute::Contains) == XFA_AttributeEnum::MetaData) {
     WideString wsNamespace;
-    bool ret = XFA_FDEExtension_ResolveNamespaceQualifier(
-        static_cast<CFX_XMLElement*>(pXMLNode),
-        GetCData(XFA_Attribute::QualifiedName), &wsNamespace);
-    if (!ret)
+    if (!XFA_FDEExtension_ResolveNamespaceQualifier(
+            element, GetCData(XFA_Attribute::QualifiedName), &wsNamespace)) {
       return {};
+    }
     return {wsNamespace};
   }
-  return {static_cast<CFX_XMLElement*>(pXMLNode)->GetNamespaceURI()};
+  return {element->GetNamespaceURI()};
 }
 
 std::pair<CXFA_Node*, int32_t> CJX_Object::GetPropertyInternal(
diff --git a/fxjs/xfa/cjx_packet.cpp b/fxjs/xfa/cjx_packet.cpp
index b27cfbadfb..2288de4c8d 100644
--- a/fxjs/xfa/cjx_packet.cpp
+++ b/fxjs/xfa/cjx_packet.cpp
@@ -35,11 +35,10 @@ CJS_Return CJX_Packet::getAttribute(
     return CJS_Return(JSGetStringFromID(JSMessage::kParamError));
 
   WideString attributeValue;
-  CFX_XMLNode* pXMLNode = GetXFANode()->GetXMLMappingNode();
-  if (pXMLNode && pXMLNode->GetType() == FX_XMLNODE_Element) {
-    attributeValue = static_cast<CFX_XMLElement*>(pXMLNode)->GetAttribute(
-        runtime->ToWideString(params[0]));
-  }
+  CFX_XMLElement* element = ToXMLElement(GetXFANode()->GetXMLMappingNode());
+  if (element)
+    attributeValue = element->GetAttribute(runtime->ToWideString(params[0]));
+
   return CJS_Return(
       runtime->NewString(attributeValue.UTF8Encode().AsStringView()));
 }
@@ -50,10 +49,10 @@ CJS_Return CJX_Packet::setAttribute(
   if (params.size() != 2)
     return CJS_Return(JSGetStringFromID(JSMessage::kParamError));
 
-  CFX_XMLNode* pXMLNode = GetXFANode()->GetXMLMappingNode();
-  if (pXMLNode && pXMLNode->GetType() == FX_XMLNODE_Element) {
-    static_cast<CFX_XMLElement*>(pXMLNode)->SetAttribute(
-        runtime->ToWideString(params[1]), runtime->ToWideString(params[0]));
+  CFX_XMLElement* element = ToXMLElement(GetXFANode()->GetXMLMappingNode());
+  if (element) {
+    element->SetAttribute(runtime->ToWideString(params[1]),
+                          runtime->ToWideString(params[0]));
   }
   return CJS_Return(runtime->NewNull());
 }
@@ -64,12 +63,11 @@ CJS_Return CJX_Packet::removeAttribute(
   if (params.size() != 1)
     return CJS_Return(JSGetStringFromID(JSMessage::kParamError));
 
-  CFX_XMLNode* pXMLNode = GetXFANode()->GetXMLMappingNode();
-  if (pXMLNode && pXMLNode->GetType() == FX_XMLNODE_Element) {
+  CFX_XMLElement* pElement = ToXMLElement(GetXFANode()->GetXMLMappingNode());
+  if (pElement) {
     WideString name = runtime->ToWideString(params[0]);
-    CFX_XMLElement* pXMLElement = static_cast<CFX_XMLElement*>(pXMLNode);
-    if (pXMLElement->HasAttribute(name))
-      pXMLElement->RemoveAttribute(name);
+    if (pElement->HasAttribute(name))
+      pElement->RemoveAttribute(name);
   }
   return CJS_Return(runtime->NewNull());
 }
@@ -77,25 +75,23 @@ CJS_Return CJX_Packet::removeAttribute(
 void CJX_Packet::content(CFXJSE_Value* pValue,
                          bool bSetting,
                          XFA_Attribute eAttribute) {
-  CFX_XMLNode* pXMLNode = GetXFANode()->GetXMLMappingNode();
+  CFX_XMLElement* element = ToXMLElement(GetXFANode()->GetXMLMappingNode());
   if (bSetting) {
-    if (pXMLNode && pXMLNode->GetType() == FX_XMLNODE_Element) {
-      auto* text = GetXFANode()
-                       ->GetDocument()
-                       ->GetNotify()
-                       ->GetHDOC()
-                       ->GetXMLDocument()
-                       ->CreateNode<CFX_XMLText>(pValue->ToWideString());
-      pXMLNode->AppendChild(text);
+    if (element) {
+      element->AppendChild(
+          GetXFANode()
+              ->GetDocument()
+              ->GetNotify()
+              ->GetHDOC()
+              ->GetXMLDocument()
+              ->CreateNode<CFX_XMLText>(pValue->ToWideString()));
     }
     return;
   }
 
   WideString wsTextData;
-  if (pXMLNode && pXMLNode->GetType() == FX_XMLNODE_Element) {
-    CFX_XMLElement* pXMLElement = static_cast<CFX_XMLElement*>(pXMLNode);
-    wsTextData = pXMLElement->GetTextData();
-  }
+  if (element)
+    wsTextData = element->GetTextData();
 
   pValue->SetString(wsTextData.UTF8Encode().AsStringView());
 }