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, 1 insertions, 0 deletions

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 915a05d..94ade96 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -18,6 +18,7 @@ add_executable(
 	src/function/read_xml_file.cc
 	src/function/read_directory.cc
 	src/support/filesystem_context.cc
+	src/support/dom_document_guard.cc
 )
 
 target_link_libraries(