event_callback with 0 bytes

[bflorac]

I have a pi running python in slave mode being fed from another pi running python in master mode. Both are using pigiod. I'm sending messages with 1 byte but occasionally, the slave gives me a call back with 0 bytes. Nothing is lost. I've go a scope and logic analyzer on the wires and there are no extra transmissions. This is just a spurious callback that happens right after a valid one. I checked the status value and nothing seems odd. Here is a valid packet followed by an invalid one. Notice the "count" shows the difference in ticks since the last call. The code for the call back does not do anything except print the data below

count 529626 1
transmit busy : false
receive FIFO empty : true
transmit FIFO full : false
receive FIFO full : false
transmit FIFO empty: false
receive busy : false
bytes in tx FIFO : 22
bytes in rx FIFO : 0
bytes copied to tx FIFO: 0
data:aa

count 1375 0
transmit busy : false
receive FIFO empty : true
transmit FIFO full : false
receive FIFO full : false
transmit FIFO empty: false
receive busy : false
bytes in tx FIFO : 22
bytes in rx FIFO : 0
bytes copied to tx FIFO: 0