Re: [HACKERS] pg_regress breaks on msys

Tom Lane wrote:
> Bruce Momjian <bruce(at)momjian(dot)us> writes:
> >> Tom Lane wrote:
> >>> The cases that I think we most need to defend against are
> >>> (A) diff program not found
>
> > In summary, on MinGW, files differ or 'diff' not found, returns 1. If
> > one of the files to be compared does not exist, it returns 2. And of
> > course, if the files are the same, it returns zero.
>
> OK. The problem here is that pg_regress is coded to assume that
> zero-length output file represents success. Given the above Windows
> behavior that is *clearly* not good enough, because that's probably
> exactly what we will see after diff-not-found (if the Windows shell
> acts like a Unix shell does and creates the ">" target first).
>
> I'd suggest modifying the logic so that zero-length output file with a
> nonzero return from the child be treated as a fatal condition (not just
> a difference, but bail out).

I modified pg_regress.c to use just the return code to determine if the
diff worked, but I added in a WIN32-specific test for the file size. I
think that is the cleanest solution. Attached.

--
Bruce Momjian bruce(at)momjian(dot)us
EnterpriseDB http://www.enterprisedb.com

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