Fixed xerces DOM construction related memory leaks

* Wrapped xerces DOM and support class instances in now DomDocumentGuard scope-guard class
* FunctionReadDirectory class contains interal std::stack instance to store DomDocumentGuard instances
** wrapped in std::shared_ptr as FunctionReadDirectory is internally cloned by xalan...
** this is needed as the DOM has to preserved longer than the external function execution scope
* Sadly XMLCh xerces strings have to be manually released
** added appropriate xercesc::XMLString::release calls
* xalan::XercesDOMWrapperParsedSource does not mirror a given xerces DOM but convert it on instantiation
** this is why there is a dedicated finalize member method in InputXSLT::DomDocumentGuard
* In short: I do not like the amount of trickery needed to simply prevent memory leaks in this context
** there sadly doesn't seem to be a substantially easier way to return arbitrary DOM trees from a external function

1 files changed, 2 insertions, 0 deletions

diff --git a/src/transformer_facade.cc b/src/transformer_facade.cc
index 01314cd..fbf604c 100644
--- a/src/transformer_facade.cc
+++ b/src/transformer_facade.cc
@@ -59,6 +59,8 @@ int TransformerFacade::execute(
 		domSupport
 	);
 
+	inputDom->release();
+
 	xalan::XSLTInputSource transform(transformation.data());
 	xalan::XSLTResultTarget output(target.data());