From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.1 (2015-04-28) on dcvr.yhbt.net X-Spam-Level: X-Spam-ASN: AS31976 209.132.180.0/23 X-Spam-Status: No, score=-4.0 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI shortcircuit=no autolearn=ham autolearn_force=no version=3.4.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by dcvr.yhbt.net (Postfix) with ESMTP id E256A1F453 for ; Fri, 28 Sep 2018 18:36:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726789AbeI2BBG (ORCPT ); Fri, 28 Sep 2018 21:01:06 -0400 Received: from esg260-1.itc.swri.edu ([129.162.252.140]:41823 "EHLO esg260-1.itc.swri.edu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726141AbeI2BBG (ORCPT ); Fri, 28 Sep 2018 21:01:06 -0400 Received: from smtp.swri.org (MBX256.adm.swri.edu [129.162.26.125]) by esg260-1.itc.swri.edu (8.16.0.22/8.16.0.22) with ESMTPS id w8SIZgEP110703 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-SHA384 bits=256 verify=NOT); Fri, 28 Sep 2018 13:35:42 -0500 Received: from MBX260.adm.swri.edu (129.162.29.125) by MBX256.adm.swri.edu (129.162.26.125) with Microsoft SMTP Server (TLS) id 15.0.1395.4; Fri, 28 Sep 2018 13:35:42 -0500 Received: from csd-17117.dyn.datasys.swri.edu (129.162.105.28) by smtp.swri.org (129.162.29.125) with Microsoft SMTP Server id 15.0.1395.4 via Frontend Transport; Fri, 28 Sep 2018 13:35:42 -0500 From: "Strain, Roger L" To: CC: Jonathan Nieder , Junio C Hamano , Stephen R Guglielmo , "David A . Greene" , Matthieu Moy , Stephen R Guglielmo , Dave Ware , David Aguilar Subject: [PATCH 4/4] subtree: improve decision on merges kept in split Date: Fri, 28 Sep 2018 13:35:40 -0500 Message-ID: <20180928183540.48968-5-roger.strain@swri.org> X-Mailer: git-send-email 2.19.0.windows.1 In-Reply-To: <20180928183540.48968-1-roger.strain@swri.org> References: <20180928183540.48968-1-roger.strain@swri.org> MIME-Version: 1.0 Content-Transfer-Encoding: 7BIT Content-Type: text/plain; charset=US-ASCII X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2018-09-28_08:,, signatures=0 X-Proofpoint-Spam-Details: rule=inbound_policy_notspam policy=inbound_policy score=0 priorityscore=1501 malwarescore=0 suspectscore=4 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=828 adultscore=0 classifier=spam adjust=-40 reason=mlx scancount=1 engine=8.0.1-1807170000 definitions=main-1809280182 Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org When multiple identical parents are detected for a commit being considered for copying, explicitly check whether one is the common merge base between the commits. If so, the other commit can be used as the identical parent; if not, a merge must be performed to maintain history. In some situations two parents of a merge commit may appear to both have identical subtree content with each other and the current commit. However, those parents can potentially come from different commit graphs. Previous behavior would simply select one of the identical parents to serve as the replacement for this commit, based on the order in which they were processed. New behavior compares the merge base between the commits to determine if a new merge commit is necessary to maintain history despite the identical content. Signed-off-by: Strain, Roger L --- contrib/subtree/git-subtree.sh | 21 +++++++++++++++++++-- 1 file changed, 19 insertions(+), 2 deletions(-) diff --git a/contrib/subtree/git-subtree.sh b/contrib/subtree/git-subtree.sh index 23dd04cbe..1c157dbd9 100755 --- a/contrib/subtree/git-subtree.sh +++ b/contrib/subtree/git-subtree.sh @@ -541,6 +541,7 @@ copy_or_skip () { nonidentical= p= gotparents= + copycommit= for parent in $newparents do ptree=$(toptree_for_commit $parent) || exit $? @@ -548,7 +549,24 @@ copy_or_skip () { if test "$ptree" = "$tree" then # an identical parent could be used in place of this rev. - identical="$parent" + if test -n "$identical" + then + # if a previous identical parent was found, check whether + # one is already an ancestor of the other + mergebase=$(git merge-base $identical $parent) + if test "$identical" = "$mergebase" + then + # current identical commit is an ancestor of parent + identical="$parent" + elif test "$parent" != "$mergebase" + then + # no common history; commit must be copied + copycommit=1 + fi + else + # first identical parent detected + identical="$parent" + fi else nonidentical="$parent" fi @@ -571,7 +589,6 @@ copy_or_skip () { fi done - copycommit= if test -n "$identical" && test -n "$nonidentical" then extras=$(git rev-list --count $identical..$nonidentical) -- 2.19.0.windows.1