HPCC-14972 Fix problems passing rows to REMOTE() graphs

ecl/hqlcpp/hqlhtcpp.cpp

@@ -7061,7 +7061,9 @@ BoundRow * HqlCppTranslator::bindSelectorAsSelf(BuildCtx & ctx, IReferenceSelect
     }
 
     //Need to bind a delta address to a new variable.
-//  throwUnexpected();  // check this is actually called
+    if (!rootRow->queryBuilder())
+        UNIMPLEMENTED_X("expected a row builder");
+
     CHqlBoundExpr offset;
     selector->getOffset(ctx, offset);
     CHqlBoundExpr address;

ecl/hqlcpp/hqlinline.cpp

@@ -1004,6 +1004,7 @@ void ParentExtract::beginCreateExtract(BuildCtx & ctx, bool doDeclare)
     //Collect a list of cursors together... NB these are in reverse order..
     gatherActiveRows(*buildctx);
 
+    serialization->BoundRow::setBuilder(queryExtractName());
     childSerialization->setBuilder(this);
 }