HPCC-8441 Ensure link counted datasets are cleared when serializing keys

Signed-off-by: Gavin Halliday <gavin.halliday@lexisnexis.com>

ecl/hqlcpp/hqlcpputil.cpp

@@ -445,3 +445,11 @@ IHqlExpression * mapInternalFunctionParameters(IHqlExpression * expr)
 
     return LINK(expr);
 }
+
+
+bool mustInitializeField(IHqlExpression * field)
+{
+    if (hasLinkCountedModifier(field))
+        return true;
+    return false;
+}

ecl/hqlcpp/hqlcpputil.hpp

@@ -51,6 +51,8 @@ extern bool canCreateTemporary(IHqlExpression * expr);
 extern IHqlExpression * projectCreateSetDataset(IHqlExpression * createsetExpr);
 extern IHqlExpression * mapInternalFunctionParameters(IHqlExpression * expr);
 
+extern bool mustInitializeField(IHqlExpression * field);
+
 //Common types and expressions...
 extern ITypeInfo * boolType;
 extern ITypeInfo * sizetType;

ecl/hqlcpp/hqlhtcpp.cpp

@@ -11005,7 +11005,6 @@ void HqlCppTranslator::generateSortCompare(BuildCtx & nestedctx, BuildCtx & ctx,
     }
 }
 
-
 void HqlCppTranslator::generateSerializeAssigns(BuildCtx & ctx, IHqlExpression * record, IHqlExpression * selector, IHqlExpression * selfSelect, IHqlExpression * leftSelect, const DatasetReference & srcDataset, const DatasetReference & tgtDataset, HqlExprArray & srcSelects, HqlExprArray & tgtSelects, bool needToClear)
 {
     ForEachChild(i, record)
@@ -11029,7 +11028,7 @@ void HqlCppTranslator::generateSerializeAssigns(BuildCtx & ctx, IHqlExpression *
                 {
                     generateSerializeAssigns(ctx, cur->queryRecord(), selected, selfSelect, leftSelect, srcDataset, tgtDataset, srcSelects, tgtSelects, needToClear);
                 }
-                else if (needToClear)
+                else if (needToClear || mustInitializeField(cur))
                 {
                     //MORE: Might want to recurse if a record
                     Owned<IHqlExpression> self = tgtDataset.mapScalar(selected, selfSelect);