Hello, According to the javadoc of TriggerResult.PURGE, "All elements in the window are cleared and the window is discarded, without evaluating the window function or emitting any elements." However, I've noticed that using a GlobalWindow (with a custom trigger) followed by an AggregateFunction will call the function's add() even when the trigger result is PURGE.
It seems to me that this has been the behavior for a very long time: https://github.com/apache/flink/commit/6cd8ceb10c841827cf89b74ecf5a0495a6933d53#diff-6d18531a35cddca6e5995c40c7a564fd711b998d567c4e167a401f76ca29a2bbR295-R299 Is that really necessary? I'm guessing that operator deals with all types of windows, so I'm not sure how that affects other window types. Regards, Alexis.
