ivp wrote:
>> The series resistor is not going to change the voltage
>> seen by the PIC input and thus will be no help.
>
> Yes, my bad. There will be a range of analogue voltage
> which causes the input FETs to not commit to a '0' or '1'
> value and even try to turn on together, making a short
> between the rails

Except for Schmitt Trigger inputs that are likely to be discussed in
this thread. Input wires within the package are of some resistance, so
the Schmitt trigger feedback would not let the input to stay stably at
that intermediate level.
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