From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Michael S. Tsirkin" Subject: [PATCH v5 5/9] patch-id: document new behaviour Date: Thu, 24 Apr 2014 12:31:04 +0300 Message-ID: <1398331809-11309-5-git-send-email-mst@redhat.com> References: <1398331809-11309-1-git-send-email-mst@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: sunshine@sunshineco.com, jrnieder@gmail.com, peff@peff.net, gitster@pobox.com To: git@vger.kernel.org X-From: git-owner@vger.kernel.org Thu Apr 24 11:32:35 2014 Return-path: Envelope-to: gcvg-git-2@plane.gmane.org Received: from vger.kernel.org ([209.132.180.67]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1WdG19-00064z-8D for gcvg-git-2@plane.gmane.org; Thu, 24 Apr 2014 11:32:31 +0200 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754949AbaDXJcJ (ORCPT ); Thu, 24 Apr 2014 05:32:09 -0400 Received: from mx1.redhat.com ([209.132.183.28]:11659 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755357AbaDXJcE (ORCPT ); Thu, 24 Apr 2014 05:32:04 -0400 Received: from int-mx11.intmail.prod.int.phx2.redhat.com (int-mx11.intmail.prod.int.phx2.redhat.com [10.5.11.24]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id s3O9VtMp025370 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 24 Apr 2014 05:31:56 -0400 Received: from redhat.com (ovpn-116-36.ams2.redhat.com [10.36.116.36]) by int-mx11.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with SMTP id s3O9UITL016060; Thu, 24 Apr 2014 05:30:18 -0400 Content-Disposition: inline In-Reply-To: <1398331809-11309-1-git-send-email-mst@redhat.com> X-Mutt-Fcc: =sent X-Scanned-By: MIMEDefang 2.68 on 10.5.11.24 Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org Archived-At: Clarify that patch ID can now be a sum of hashes, not a hash. Document how command line and config options affect the behaviour. Signed-off-by: Michael S. Tsirkin --- Documentation/git-patch-id.txt | 23 ++++++++++++++++++----- 1 file changed, 18 insertions(+), 5 deletions(-) diff --git a/Documentation/git-patch-id.txt b/Documentation/git-patch-id.txt index 312c3b1..e21b79b 100644 --- a/Documentation/git-patch-id.txt +++ b/Documentation/git-patch-id.txt @@ -8,14 +8,14 @@ git-patch-id - Compute unique ID for a patch SYNOPSIS -------- [verse] -'git patch-id' < +'git patch-id' [--stable | --unstable] < DESCRIPTION ----------- -A "patch ID" is nothing but a SHA-1 of the diff associated with a patch, with -whitespace and line numbers ignored. As such, it's "reasonably stable", but at -the same time also reasonably unique, i.e., two patches that have the same "patch -ID" are almost guaranteed to be the same thing. +A "patch ID" is nothing but a sum of SHA-1 of the diff hunks associated with a +patch, with whitespace and line numbers ignored. As such, it's "reasonably +stable", but at the same time also reasonably unique, i.e., two patches that +have the same "patch ID" are almost guaranteed to be the same thing. IOW, you can use this thing to look for likely duplicate commits. @@ -27,6 +27,19 @@ This can be used to make a mapping from patch ID to commit ID. OPTIONS ------- + +--stable:: + Use a symmetrical sum of hashes as the patch ID. + With this option, reordering file diffs that make up a patch or + splitting a diff up to multiple diffs that touch the same path + does not affect the ID. + This is the default if patchid.stable is set to true. + +--unstable:: + Use a non-symmetrical sum of hashes, such that reordering + or splitting the patch does affect the ID. + This is the default. + :: The diff to create the ID of. -- MST