From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Michael S. Tsirkin" Subject: [PATCH v4 5/6] patch-id: document new behaviour Date: Wed, 23 Apr 2014 15:15:02 +0300 Message-ID: <1398255277-26303-5-git-send-email-mst@redhat.com> References: <1398255277-26303-1-git-send-email-mst@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii To: git@vger.kernel.org X-From: git-owner@vger.kernel.org Wed Apr 23 14:14:37 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 1Wcw4S-0007a4-Dj for gcvg-git-2@plane.gmane.org; Wed, 23 Apr 2014 14:14:36 +0200 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753332AbaDWMOV (ORCPT ); Wed, 23 Apr 2014 08:14:21 -0400 Received: from mx1.redhat.com ([209.132.183.28]:57120 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753261AbaDWMOS (ORCPT ); Wed, 23 Apr 2014 08:14:18 -0400 Received: from int-mx10.intmail.prod.int.phx2.redhat.com (int-mx10.intmail.prod.int.phx2.redhat.com [10.5.11.23]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id s3NCEHgx003092 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK) for ; Wed, 23 Apr 2014 08:14:18 -0400 Received: from redhat.com (ovpn-116-36.ams2.redhat.com [10.36.116.36]) by int-mx10.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with SMTP id s3NCEGow018247 for ; Wed, 23 Apr 2014 08:14:17 -0400 Content-Disposition: inline In-Reply-To: <1398255277-26303-1-git-send-email-mst@redhat.com> X-Mutt-Fcc: =sent X-Scanned-By: MIMEDefang 2.68 on 10.5.11.23 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 | 25 ++++++++++++++++++++----- 1 file changed, 20 insertions(+), 5 deletions(-) diff --git a/Documentation/git-patch-id.txt b/Documentation/git-patch-id.txt index 312c3b1..61d4a67 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 +27,21 @@ 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, or if patchid.stable + is not set and diff.orderfile is set to some value. + +--unstable:: + Use a non-symmetrical sum of hashes, such that reordering + or splitting the patch does affect the ID. + This is the default if patchid.stable is set to false, or if neither patchid.stable + nor diff.orderfile are set. + :: The diff to create the ID of. -- MST