Free xmlDoc structure at the end of xccdf_session_load

When calling the xccdf_session_load_(xccdf|cpe|oval|tailoring)
functions, the session->source structure is recopied to
session->ds.session->component_sources, including the
source->xml.doc field, which contains the XML DOM.

This change adds a new oscap_source_free_xmlDoc function to the
OSCAP source API and call it at the end of the xccdf_session_load
function, so session->source->xml.doc is freed when it's not used
anymore.

Author: 0intro

src/XCCDF/xccdf_session.c

@@ -716,7 +716,9 @@ int xccdf_session_load(struct xccdf_session *session)
 			return ret;
 		}
 	}
-	return xccdf_session_load_tailoring(session);
+	ret = xccdf_session_load_tailoring(session);
+	oscap_source_free_xmlDoc(session->source);
+	return ret;
 }
 
 static int _reporter(const char *file, int line, const char *msg, void *arg)

src/source/oscap_source.c

@@ -153,6 +153,16 @@ void oscap_source_free(struct oscap_source *source)
 	}
 }
 
+void oscap_source_free_xmlDoc(struct oscap_source *source)
+{
+	if (source != NULL) {
+		if (source->xml.doc != NULL) {
+			xmlFreeDoc(source->xml.doc);
+			source->xml.doc = NULL;
+		}
+	}
+}
+
 /**
  * Returns human readable description of oscap_source origin
  */

src/source/public/oscap_source.h

@@ -95,6 +95,12 @@ OSCAP_API struct oscap_source *oscap_source_clone(struct oscap_source *old);
  */
 OSCAP_API void oscap_source_free(struct oscap_source *source);
 
+/**
+ * Dispose oscap_source xmlDoc structure.
+ * @param source Resource to dispose xmlDoc structure from
+ */
+OSCAP_API void oscap_source_free_xmlDoc(struct oscap_source *source);
+
 /**
  * Get filepath of the given resource
  * @memberof oscap_source