Add extra checks in CXMLImpl::ParseString to avoid crash when invalid XML data supplied (#2282)

* Add extra checks in CXMLImpl::ParseString

* Change back to default encoding (left from testing)

Author: Lpsd

Shared/XML/CXMLImpl.cpp

@@ -50,9 +50,17 @@ std::unique_ptr<SXMLString> CXMLImpl::ParseString(const char* strXmlContent)
         if (!xmlDoc->Error())
         {
             TiXmlElement* xmlDocumentRoot = xmlDoc->RootElement();
-            CXMLNodeImpl* xmlBaseNode = new CXMLNodeImpl(nullptr, nullptr, *xmlDocumentRoot);
-            xmlBaseNode->BuildFromDocument();
-            return std::unique_ptr<SXMLString>(new SXMLStringImpl(xmlDoc, xmlBaseNode));
+
+            if (xmlDocumentRoot)
+            {
+                CXMLNodeImpl* xmlBaseNode = new CXMLNodeImpl(nullptr, nullptr, *xmlDocumentRoot);
+
+                if (xmlBaseNode && xmlBaseNode->IsValid())
+                {
+                    xmlBaseNode->BuildFromDocument();
+                    return std::unique_ptr<SXMLString>(new SXMLStringImpl(xmlDoc, xmlBaseNode));
+                }
+            }
         }
     }
     return nullptr;