pigpio: Glitch filter creation causes unexpected level change callback

The following code seems to trigger a callback, when I would expect no callback to be triggered.

I’ve been able to reliably cause this when running the script from a remote computer connected to the pi, but have also seen this on the pi itself (but much less often). It seems like it might have to do with setting the glitch filter since I have not been able to reproduce the behavior with the glitch filter lines removed.

I haven’t done a full investigation yet, but I would like to get some feedback on whether this is expected or not.

I’m using a raspberry pi model 3B+ with pigpio version 1.46 and python 2.7.

This is what I see when I run remotely (I would expect to see no output):

$ python test.py
gpio = 25, level = 0, tick = 2990614791
gpio = 25, level = 1, tick = 2990638556

import pigpio
import time

def cbf(gpio, level, tick):
    print("gpio = {}, level = {}, tick = {}".format(gpio, level, tick))

if __name__ == "__main__":
    pi = pigpio.pi("pi")

    pi.set_mode(24, pigpio.INPUT)
    pi.set_pull_up_down(24, pigpio.PUD_OFF)
    pi.set_glitch_filter(24, 0)
    pi.set_mode(24, pigpio.INPUT)
    pi.set_pull_up_down(24, pigpio.PUD_UP)
    pi.set_glitch_filter(24, .1*1e6)

    pi.callback(24, pigpio.EITHER_EDGE, cbf)

    pi.set_mode(25, pigpio.INPUT)
    pi.set_pull_up_down(25, pigpio.PUD_OFF)
    pi.set_glitch_filter(25, 0)
    pi.set_mode(25, pigpio.INPUT)
    pi.set_pull_up_down(25, pigpio.PUD_UP)
    pi.set_glitch_filter(25, .1*1e6)

    pi.callback(25, pigpio.EITHER_EDGE, cbf)

    # Phantom callback usually occurs within the first 2s
    time.sleep(2)

(This code is a distillation of what gpiozero is doing when setting up a Button with a pigpio backend, so it might look a little strange)

Thanks for this great library, I appreciate the great documentation and hardware capabilities.