Re: [PATCH 10/9 v2] test-mergesort: use repeatable random numbers

On Fri, Oct 08, 2021 at 06:04:42AM +0200, René Scharfe wrote:

Use MINSTD to generate pseudo-random numbers consistently instead of
using rand(3), whose output can vary from system to system, and reset
its seed before filling in the test values.  This gives repeatable
results across versions and systems, which simplifies sharing and
comparing of results between developers.

Nice. As a bonus, I noticed that Coverity complains about the use of
rand() as a security red-flag (even though of course we don't care about
its quality here). This should get rid of it by hiding the same thing in
a custom implementation. ;)

We have a similar LCG in t/helper/test-genrandom.c, but I don't think
there's any reason this needs to be factored into a shared one. And in
particular, I'd be loathe to change the genrandom one, as it may create
small bugs in the test suite (cases where we rely on hashes of the data
having particular attributes).

-Peff