From mboxrd@z Thu Jan  1 00:00:00 1970
Message-ID: <35bd6c09a1f8cc6b79507c3dde215e81@collyer.net>
To: 9fans@cse.psu.edu
Subject: Re: [9fans] compare-by-hash
From: Geoff Collyer <geoff@collyer.net>
In-Reply-To: <83292e13cedded89b34cb69fea8b7c3d@caldo.demon.co.uk>
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Date: Sun,  1 Jun 2003 15:55:15 -0700
Topicbox-Message-UUID: c1851b56-eacb-11e9-9e20-41e7f4b1d025

I got jackpots from V6 diff often enough that I can still remember
getting them.  I can't recall any since then, and just looked at the
V7 diff sources to see why:

/*
	if(jackpot)
		mesg("jackpot",empty);
*/

Here's the explanation of what a jackpot is, from
/sys/src/cmd/diff/diffreg.c:53,58 even though Plan 9 diff no longer
contains any other references to jackpots:

*	With J in hand, the matches there recorded are
*	check'ed against reality to assure that no spurious
*	matches have crept in due to hashing. If they have,
*	they are broken, and "jackpot " is recorded--a harmless
*	matter except that a true match for a spuriously
*	mated line may now be unnecessarily reported as a change.