Add a parameter checker in CXFA_ScriptContext::QueryNodeByFlag()

BUG=pdfium:380
R=tsepez@chromium.org

Review URL: https://codereview.chromium.org/1674453004 .

2 files changed, 19 insertions, 17 deletions

diff --git a/xfa/src/fxfa/src/parser/xfa_script_imp.cpp b/xfa/src/fxfa/src/parser/xfa_script_imp.cpp
index 00b9b945fa..3c8e1c14a3 100644
--- a/xfa/src/fxfa/src/parser/xfa_script_imp.cpp
+++ b/xfa/src/fxfa/src/parser/xfa_script_imp.cpp
@@ -143,23 +143,24 @@ FX_BOOL CXFA_ScriptContext::QueryNodeByFlag(CXFA_Node* refNode,
                                             FXJSE_HVALUE hValue,
                                             FX_DWORD dwFlag,
                                             FX_BOOL bSetting) {
+  if (!refNode)
+    return false;
   XFA_RESOLVENODE_RS resolveRs;
-  int32_t iRet = ResolveObjects(refNode, propname, resolveRs, dwFlag);
-  FX_BOOL bResult = FALSE;
-  if (iRet > 0) {
-    bResult = TRUE;
-    if (resolveRs.dwFlags == XFA_RESOVENODE_RSTYPE_Nodes) {
-      FXJSE_HVALUE pValue = GetJSValueFromMap(resolveRs.nodes[0]);
-      FXJSE_Value_Set(hValue, pValue);
-    } else if (resolveRs.dwFlags == XFA_RESOVENODE_RSTYPE_Attribute) {
-      XFA_LPCSCRIPTATTRIBUTEINFO lpAttributeInfo = resolveRs.pScriptAttribute;
-      if (lpAttributeInfo) {
-        (resolveRs.nodes[0]->*(lpAttributeInfo->lpfnCallback))(
-            hValue, bSetting, (XFA_ATTRIBUTE)lpAttributeInfo->eAttribute);
-      }
+  if (ResolveObjects(refNode, propname, resolveRs, dwFlag) <= 0)
+    return false;
+  if (resolveRs.dwFlags == XFA_RESOVENODE_RSTYPE_Nodes) {
+    FXJSE_HVALUE pValue = GetJSValueFromMap(resolveRs.nodes[0]);
+    FXJSE_Value_Set(hValue, pValue);
+    return true;
+  }
+  if (resolveRs.dwFlags == XFA_RESOVENODE_RSTYPE_Attribute) {
+    XFA_LPCSCRIPTATTRIBUTEINFO lpAttributeInfo = resolveRs.pScriptAttribute;
+    if (lpAttributeInfo) {
+      (resolveRs.nodes[0]->*(lpAttributeInfo->lpfnCallback))(
+          hValue, bSetting, (XFA_ATTRIBUTE)lpAttributeInfo->eAttribute);
     }
   }
-  return bResult;
+  return true;
 }
 void CXFA_ScriptContext::GlobalPropertyGetter(FXJSE_HOBJECT hObject,
                                               const CFX_ByteStringC& szPropName,
@@ -479,7 +480,7 @@ FX_BOOL CXFA_ScriptContext::QueryVariableHValue(
     const CFX_ByteStringC& szPropName,
     FXJSE_HVALUE hValue,
     FX_BOOL bGetter) {
-  if (pScriptNode->GetClassID() != XFA_ELEMENT_Script) {
+  if (!pScriptNode || pScriptNode->GetClassID() != XFA_ELEMENT_Script) {
     return FALSE;
   }
   CXFA_Node* variablesNode = pScriptNode->GetNodeItem(XFA_NODEITEM_Parent);
diff --git a/xfa/src/fxfa/src/parser/xfa_script_nodehelper.cpp b/xfa/src/fxfa/src/parser/xfa_script_nodehelper.cpp
index 8fe9348b51..7ef7382f69 100644
--- a/xfa/src/fxfa/src/parser/xfa_script_nodehelper.cpp
+++ b/xfa/src/fxfa/src/parser/xfa_script_nodehelper.cpp
@@ -43,11 +43,12 @@ int32_t CXFA_NodeHelper::XFA_CountSiblings(CXFA_Node* pNode,
                                            XFA_LOGIC_TYPE eLogicType,
                                            CXFA_NodeArray* pSiblings,
                                            FX_BOOL bIsClassName) {
+  if (!pNode)
+    return 0;
   CXFA_Node* parent =
       XFA_ResolveNodes_GetParent(pNode, XFA_LOGIC_NoTransparent);
-  if (parent == NULL) {
+  if (!parent)
     return 0;
-  }
   XFA_LPCPROPERTY pPropert = XFA_GetPropertyOfElement(
       parent->GetClassID(), pNode->GetClassID(), XFA_XDPPACKET_UNKNOWN);
   if (!pPropert && eLogicType == XFA_LOGIC_Transparent) {