Support OUTPUT inside APPLY in roxie

I posted something on HPCC Forums and was told to create a ticket here.

Just would like to understand strange behavior of APPLY() used with hThor when OUTPUTing to logical file.

ECL code to reproduce:

layout := { STRING letter; };
ds := DATASET([\{'A'},\{'B'},\{'C'}], layout);
APPLY(ds, OUTPUT(DATASET([letter],layout),,'~temp::letters::'+letter, OVERWRITE));

Questions brought up by Richard Taylor:

So, I have a couple of problems with this code:

• Based on the above actionlist text, why does it syntax check at all, much less run (even just on hThor)?

• And only then am I wondering why all three files contain the same data?

Richard Taylor reply on forums: https://hpccsystems.com/bb/viewtopic.php?f=8&t=6023&p=23451#p23433