From mboxrd@z Thu Jan 1 00:00:00 1970 From: Junio C Hamano Subject: Re: [PATCH 2/2] xdiff: implement empty line chunk heuristic Date: Tue, 19 Apr 2016 23:00:17 -0700 Message-ID: References: <1461013950-12503-1-git-send-email-sbeller@google.com> <1461013950-12503-3-git-send-email-sbeller@google.com> <20160419050342.GA19439@sigill.intra.peff.net> <20160419170624.GA3999@sigill.intra.peff.net> Mime-Version: 1.0 Content-Type: text/plain Cc: Stefan Beller , "git\@vger.kernel.org" , Jacob Keller , Jacob Keller To: Jeff King X-From: git-owner@vger.kernel.org Wed Apr 20 08:00:26 2016 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 1aslBY-0005R5-VU for gcvg-git-2@plane.gmane.org; Wed, 20 Apr 2016 08:00:25 +0200 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753435AbcDTGAV (ORCPT ); Wed, 20 Apr 2016 02:00:21 -0400 Received: from pb-smtp1.pobox.com ([64.147.108.70]:57732 "EHLO sasl.smtp.pobox.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752692AbcDTGAU (ORCPT ); Wed, 20 Apr 2016 02:00:20 -0400 Received: from sasl.smtp.pobox.com (unknown [127.0.0.1]) by pb-smtp1.pobox.com (Postfix) with ESMTP id EAC2F15E17; Wed, 20 Apr 2016 02:00:18 -0400 (EDT) DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=pobox.com; h=from:to:cc :subject:references:date:in-reply-to:message-id:mime-version :content-type; s=sasl; bh=PelRL/5ME6CZHHKu5EDpUzNT51I=; b=Yj++lt MAJq5uKBSDDceEOTRnTKr2G8kIKAHTiwC9fpXYiLUL+t/kPwv3CAB5Uc0YP0yauu mr5XL+Hbn0bCcE0hC/s03tqB56EtqT0dz3NWaZQ0IQczLngEGW+VRLm4YE1qklbl vZo3KoTwhGz8cAs8besHJN0P4o8JFXRwWwpkw= DomainKey-Signature: a=rsa-sha1; c=nofws; d=pobox.com; h=from:to:cc :subject:references:date:in-reply-to:message-id:mime-version :content-type; q=dns; s=sasl; b=kyVcAN/ZyVUrhRid4+OHWHmYSkgesSdR 4gGqm/hGw9+RFIcsYN/jGneL7d9YGVkVUYeTaE2gLz8FtDoNE8YRUQsKML/Dnp0j v8J0dW39pLWSuFIQnkWpJi6oGl8DV/FJYVcTA2tWJj0Ihc7edLOn/G9rzpRul+F0 tURhIFKmlJE= Received: from pb-smtp1. (unknown [127.0.0.1]) by pb-smtp1.pobox.com (Postfix) with ESMTP id DF2B015E16; Wed, 20 Apr 2016 02:00:18 -0400 (EDT) Received: from pobox.com (unknown [104.132.0.95]) (using TLSv1.2 with cipher DHE-RSA-AES128-SHA (128/128 bits)) (No client certificate requested) by pb-smtp1.pobox.com (Postfix) with ESMTPSA id 33D6215E15; Wed, 20 Apr 2016 02:00:18 -0400 (EDT) In-Reply-To: <20160419170624.GA3999@sigill.intra.peff.net> (Jeff King's message of "Tue, 19 Apr 2016 13:06:25 -0400") User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.3 (gnu/linux) X-Pobox-Relay-ID: 28B4DE16-06BD-11E6-8339-9A9645017442-77302942!pb-smtp1.pobox.com Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org Archived-At: Jeff King writes: > I mean that if you save any old patch-ids from "git patch-id", they > won't match up when compared with new versions of git. We can probably > ignore it, though. This isn't the first time that patch-ids might have > changed, and I think the advice is already that one should not count on > them to be stable in the long term. Another thing that this *will* break is the patch signature upload protocol k.org uses to allow Linus, Greg, et al. on the road with limited hotel wifi bandwidth to prepare patch-X-test1.gz and patch-X-test1.sign file. They can locally tag X-test1, prepare "git diff X X-test1 | gzip -n >patch-X-test1.gz" and sign the result, and upload _only_ the detached signature after pushing. They can tell k.org, when uploading the detached signature, to recreate the patchfile by running the same "git diff" to save the bandwidth of sending the same thing twice (as they have to "push" anyway, having to send the generated patch is a pure overhead). Having said all that, kup(1) users are already warned that the textual diff produced by "git diff-tree -p" (which is mentioned in the documentation of the tool) varies across versions of Git and the above "optimization" would not work unless both ends have the same version of Git, so it may not be too big an issue for them. They have already been burned once when we corrected "git archive" output in the past (they obviously have the same optimization to sign tarballs, and the kup(1) mechanism relies to have byte-for-byte identical output).