Please read WikiStart to learn how to properly post code on the issue tracker. In case you didn't notice: This isn't the forum.
Now, as for the ticket itself... okay, and? The documentation clearly states to check the error property on the AutoItX3 object to see if a call to Run() or RunWait() failed. I don't see you checking that property so the return value of 0 is expected.
Finally, I am pretty sure this is not a bug. There are OS-imposed limits on the length of the command line and its parameters. I'll test it but I don't expect to find a problem in AutoIt(X).