Add a faq regarding the two versions of transcode (one with a mem mgr and one without)

git-svn-id: https://svn.apache.org/repos/asf/xerces/c/trunk@175767 13f79535-47bb-0310-9956-ffa450edef68

doc/faq-parse.xml

@@ -897,5 +897,23 @@ delete parser;
       
     </a>
   </faq>
+
+  <faq title="Why do we have two versions of XMLString::transcode (one with memory manager and one without)?">
+
+    <q>Why do we have two versions of XMLString::transcode (one with memory manager and one without)?</q>
+
+    <a>
+
+      <p>With the introdcution of the configurable memory manager, we didn't want to break users by
+         changing the signature of the method. Also, we did not want to provide a default memory
+         manager as it would introduce a side effect with users experiencing some strange core dumps.
+         The latter will occur when the scope of the string allocated is beyond that of
+         XMLPlatformUtils::Terminate (i.e. a string is allocated using the default memory manager
+         which is deleted when XMLPlatformUtils::Terminate is called, but the allocated string is
+         deleted later). We plan to deprecate the transcode method with no parameters in later releases.
+      </p>
+
+    </a>
+  </faq>
   
 </faqs>