Re: USE_NSEC bug?

From: Junio C Hamano <gitster@pobox.com>
Date: Mar 20, 2013, 17:04 UTC
Message-ID: <7vppyuf1f5.fsf@alter.siamese.dyndns.org>
In-Reply-To: <20130320075344.GA8159@sigill.intra.peff.net>

Jeff King <peff@peff.net> writes:

> But maybe there is some subtle reason I'm missing for having the two
> options separate.

The closest I found was c06ff4908bf9 (Record ns-timestamps if possible, but do not use it without USE_NSEC, 2009-03-04).

commit c06ff4908bf9ad8bf2448439a3574321c9399b17
Author: Kjetil Barvik <barvik@broadpark.no>
Date:   Wed Mar 4 18:47:40 2009 +0100

    Record ns-timestamps if possible, but do not use it without USE_NSEC
    
    Traditionally, the lack of USE_NSEC meant "do not record nor use the
    nanosecond resolution part of the file timestamps".  To avoid problems on
    filesystems that lose the ns part when the metadata is flushed to the disk
    and then later read back in, disabling USE_NSEC has been a good idea in
    general.
    
    If you are on a filesystem without such an issue, it does not hurt to read
    and store them in the cached stat data in the index entries even if your
    git is compiled without USE_NSEC.  The index left with such a version of
    git can be read by git compiled with USE_NSEC and it can make use of the
    nanosecond part to optimize the check to see if the path on the filesystem
    hsa been modified since we last looked at.