From mboxrd@z Thu Jan  1 00:00:00 1970
From: Junio C Hamano <gitster@pobox.com>
Subject: Re: Index format v5
Date: Thu, 03 May 2012 12:03:52 -0700
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References: <CALgYhfMKdbv8TiT4ALDSvD3pSXHEPLWHM09DxYnRmRdBWRjh8Q@mail.gmail.com>
 <87obq5p1t0.fsf@thomas.inf.ethz.ch>
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Cc: Thomas Gummerer <t.gummerer@gmail.com>, <git@vger.kernel.org>,
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To: Thomas Rast <trast@student.ethz.ch>
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Thomas Rast <trast@student.ethz.ch> writes:

> So what's wrong in this thinking?

We tolerate giving occasional false positive "Yes" to "Has this changed?",
but do not allow false negative "No".  So the value st_{ino,dev,uid,gid}
gives us is strictly "these are not likely to change, but if even a single
bit in them change, we need to suspect that it may have changed."  The
primary field that protect us is mtime, and all the rest are more or less
belt-and-suspender safety.