Re: BUG #17777: An assert failed in nodeWindowAgg.c

Andres Freund <andres@anarazel.de> writes:
> The problem is that normally we supress the moving aggregate optimization if a
> volatile function is contained in the filter. But unfortunately,
> contain_volatile_functions() doesn't descend into subplans. So we don't see
> the volatile expression.

I would say that if a volatile function in the argument crashes things,
that's an executor bug.  You won't get any sympathy from me for
complaints about whether contain_volatile_functions noticed that,
because *immutability markings can be lies*.  It is not acceptable
to crash if they're wrong.

It looks to me like maybe we could just remove the Assert and do

-    if (peraggstate->transValueCount == 1)
+    if (peraggstate->transValueCount < 2)

a few lines further down?  I've not dug into the details though.

            regards, tom lane