Variables can be uninitialized causing undefined behavior.
Description
Variables can be uninitialized causing undefined behavior. I've seen this crash bro via a NOTICE call, and I think it is why the broker logging event issue() crashes inside the software framework.
See this example, which is a common mistake:
you'd expect this to trigger a reporter error of some sort, but instead it prints a random variable:
This program DOES work correctly:
Environment
Activity
Oh, and as a real world example, something like this was found to crash the manager on a cluster:
This looks like the relevant function, in Expr.cc:
For Justin's code, there is a Frame pointer passed in, so the following gets evaluated.
I believe that offset is initialized to 0, but not actually set. NthElement just does:
So I think that somehow we need to check that the variable has actually been set.
topic/jsiwek/bit-1785 has a potential fix for this
The problem was that for functions w/ multiple bodies (i.e. events or hooks), the identifier offsets within the stack frame of a given body pointed to the values of whatever was in the last-executed body at that same offset.
