Memory leaks in OLW XML streamer ReadObject methods

[bero]

The XML streamers for OLW (OCL Light Weight) nodes in BoldOclLightWeightNodes.pas have memory leaks in their ReadObject methods. When deserializing from XML, CreateObject calls a constructor that allocates internal lists, then ReadObject overwrites the field pointer with the deserialized object — orphaning the constructor-allocated one.

Affected methods

Streamer	Leaked field	Constructor that allocates it
TBoldXMLOLWOperationStreamer.ReadObject	fArgs (TBoldOLWNodeList)	TBoldOLWOperation.Create
TBoldXMLOLWMemberStreamer.ReadObject	fQualifier (TBoldOLWNodeList)	TBoldOLWMember.Create
TBoldXMLOCLConditionStreamer.ReadObject	fEnv (TBoldOLWNodeList)	TBoldOclCondition.Create
TBoldXMLOCLConditionStreamer.ReadObject	fContext (TBoldObjectIdList)	TBoldOclCondition.Create

Impact

These streamers are invoked when OCL conditions are serialized/deserialized over XML, typically in distributed (SOAP) Bold persistence setups. Single-tier applications that evaluate OCL locally are not affected.

Each deserialization of an TBoldOclCondition leaks 4 objects (the NodeList, its internal TList, and for Context also TBoldObjectIdList + TBoldIntegerIndex).

Fix

Add FreeAndNil before each field assignment in ReadObject to free the constructor-allocated object before replacing it:

// Before (leaks):

OLWOperation.fArgs := Node.ReadSubNodeObject('Args', '') as TBoldOLWNodeList;

// After (fixed):

FreeAndNil(OLWOperation.fArgs);
OLWOperation.fArgs := Node.ReadSubNodeObject('Args', '') as TBoldOLWNodeList;

Same pattern for all 4 fields.
This is tested in class TTestBoldOLWNodeXMLStreaming