In theory, it's possible that some consequences could use "0"
as one of their parameters. At least change tags, see T296642.
But PHP treats "0" as false.
Also make the code on all places consistent.
Change-Id: I5255dfb26878ceb4f78c4d8277521edbb4821d7d
In particular, this brings stronger typing for getID(), and we can get
rid of many phan suppressions.
Change-Id: Icbf3a6f7db8105082646ec227f62c09449fb165d