tests: fix potential divide by zero condition
Running clang's static analysis revealed a possible divide by zero
condition.
There is a random chance of the divide by zero.
- it has to be in the first pass of the main loop testing events
(counter = 0)
- 90% chance path : if (counter < (NUMEVENTS -1) &&
random() % 10 == 0) -- needs to be false
- 25% chance path: if (random() % 4 == 0) -- needs to be true
if the above conditions are met, the statement
int victim = random() % counter
is a divide by zero.
Add a check to ensure the counter is greater than zero. Add a comment
to document that only events prior to the current event are randomly
selected.
Change-Id: I4b4e73fa324842bb504bcc952079af15aea8a6a3
Reviewed-on: https://gerrit.openafs.org/14501
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Andrew Deason <adeason@sinenomine.net>
Reviewed-by: Michael Meffie <mmeffie@sinenomine.net>
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>