From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on dcvr.yhbt.net X-Spam-Level: X-Spam-ASN: AS31976 209.132.180.0/23 X-Spam-Status: No, score=-3.4 required=3.0 tests=AWL,BAYES_00, DKIM_ADSP_CUSTOM_MED,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI shortcircuit=no autolearn=ham autolearn_force=no version=3.4.0 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by dcvr.yhbt.net (Postfix) with ESMTP id 4310F1F404 for ; Thu, 19 Apr 2018 18:01:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753359AbeDSSBB (ORCPT ); Thu, 19 Apr 2018 14:01:01 -0400 Received: from mx0a-00153501.pphosted.com ([67.231.148.48]:42102 "EHLO mx0a-00153501.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751876AbeDSR6g (ORCPT ); Thu, 19 Apr 2018 13:58:36 -0400 Received: from pps.filterd (m0096528.ppops.net [127.0.0.1]) by mx0a-00153501.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id w3JHw6ij014678; Thu, 19 Apr 2018 10:58:29 -0700 Authentication-Results: palantir.com; spf=softfail smtp.mailfrom=newren@gmail.com Received: from smtp-transport.yojoe.local (mxw3.palantir.com [66.70.54.23] (may be forged)) by mx0a-00153501.pphosted.com with ESMTP id 2hdry1au85-1; Thu, 19 Apr 2018 10:58:28 -0700 Received: from mxw1.palantir.com (new-smtp.yojoe.local [172.19.0.45]) by smtp-transport.yojoe.local (Postfix) with ESMTP id 8F62422175C0; Thu, 19 Apr 2018 10:58:28 -0700 (PDT) Received: from newren2-linux.yojoe.local (newren2-linux.pa.palantir.tech [10.100.71.66]) by smtp.yojoe.local (Postfix) with ESMTP id 867CD2CDEED; Thu, 19 Apr 2018 10:58:28 -0700 (PDT) From: Elijah Newren To: git@vger.kernel.org Cc: sbeller@google.com, gitster@pobox.com, torvalds@linux-foundation.org, Elijah Newren Subject: [PATCH v10 08/36] directory rename detection: testcases exploring possibly suboptimal merges Date: Thu, 19 Apr 2018 10:57:55 -0700 Message-Id: <20180419175823.7946-9-newren@gmail.com> X-Mailer: git-send-email 2.17.0.290.ge988e9ce2a In-Reply-To: <20180419175823.7946-1-newren@gmail.com> References: <20180419175823.7946-1-newren@gmail.com> X-Proofpoint-SPF-Result: softfail X-Proofpoint-SPF-Record: v=spf1 redirect=_spf.google.com X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2018-04-19_05:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=4 phishscore=0 bulkscore=0 spamscore=0 clxscore=1034 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1711220000 definitions=main-1804190157 Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org Reviewed-by: Stefan Beller Signed-off-by: Elijah Newren Signed-off-by: Junio C Hamano --- t/t6043-merge-rename-directories.sh | 404 ++++++++++++++++++++++++++++ 1 file changed, 404 insertions(+) diff --git a/t/t6043-merge-rename-directories.sh b/t/t6043-merge-rename-directories.sh index 6db1439675..e211e8ca31 100755 --- a/t/t6043-merge-rename-directories.sh +++ b/t/t6043-merge-rename-directories.sh @@ -1912,4 +1912,408 @@ test_expect_failure '7e-check: transitive rename in rename/delete AND dirs in th ) ' +########################################################################### +# SECTION 8: Suboptimal merges +# +# As alluded to in the last section, the ruleset we have built up for +# detecting directory renames unfortunately has some special cases where it +# results in slightly suboptimal or non-intuitive behavior. This section +# explores these cases. +# +# To be fair, we already had non-intuitive or suboptimal behavior for most +# of these cases in git before introducing implicit directory rename +# detection, but it'd be nice if there was a modified ruleset out there +# that handled these cases a bit better. +########################################################################### + +# Testcase 8a, Dual-directory rename, one into the others' way +# Commit O. x/{a,b}, y/{c,d} +# Commit A. x/{a,b,e}, y/{c,d,f} +# Commit B. y/{a,b}, z/{c,d} +# +# Possible Resolutions: +# w/o dir-rename detection: y/{a,b,f}, z/{c,d}, x/e +# Currently expected: y/{a,b,e,f}, z/{c,d} +# Optimal: y/{a,b,e}, z/{c,d,f} +# +# Note: Both x and y got renamed and it'd be nice to detect both, and we do +# better with directory rename detection than git did without, but the +# simple rule from section 5 prevents me from handling this as optimally as +# we potentially could. + +test_expect_success '8a-setup: Dual-directory rename, one into the others way' ' + test_create_repo 8a && + ( + cd 8a && + + mkdir x && + mkdir y && + echo a >x/a && + echo b >x/b && + echo c >y/c && + echo d >y/d && + git add x y && + test_tick && + git commit -m "O" && + + git branch O && + git branch A && + git branch B && + + git checkout A && + echo e >x/e && + echo f >y/f && + git add x/e y/f && + test_tick && + git commit -m "A" && + + git checkout B && + git mv y z && + git mv x y && + test_tick && + git commit -m "B" + ) +' + +test_expect_failure '8a-check: Dual-directory rename, one into the others way' ' + ( + cd 8a && + + git checkout A^0 && + + git merge -s recursive B^0 && + + git ls-files -s >out && + test_line_count = 6 out && + git ls-files -u >out && + test_line_count = 0 out && + git ls-files -o >out && + test_line_count = 1 out && + + git rev-parse >actual \ + HEAD:y/a HEAD:y/b HEAD:y/e HEAD:y/f HEAD:z/c HEAD:z/d && + git rev-parse >expect \ + O:x/a O:x/b A:x/e A:y/f O:y/c O:y/d && + test_cmp expect actual + ) +' + +# Testcase 8b, Dual-directory rename, one into the others' way, with conflicting filenames +# Commit O. x/{a_1,b_1}, y/{a_2,b_2} +# Commit A. x/{a_1,b_1,e_1}, y/{a_2,b_2,e_2} +# Commit B. y/{a_1,b_1}, z/{a_2,b_2} +# +# w/o dir-rename detection: y/{a_1,b_1,e_2}, z/{a_2,b_2}, x/e_1 +# Currently expected: +# Scary: y/{a_1,b_1}, z/{a_2,b_2}, CONFLICT(add/add, e_1 vs. e_2) +# Optimal: y/{a_1,b_1,e_1}, z/{a_2,b_2,e_2} +# +# Note: Very similar to 8a, except instead of 'e' and 'f' in directories x and +# y, both are named 'e'. Without directory rename detection, neither file +# moves directories. Implement directory rename detection suboptimally, and +# you get an add/add conflict, but both files were added in commit A, so this +# is an add/add conflict where one side of history added both files -- +# something we can't represent in the index. Obviously, we'd prefer the last +# resolution, but our previous rules are too coarse to allow it. Using both +# the rules from section 4 and section 5 save us from the Scary resolution, +# making us fall back to pre-directory-rename-detection behavior for both +# e_1 and e_2. + +test_expect_success '8b-setup: Dual-directory rename, one into the others way, with conflicting filenames' ' + test_create_repo 8b && + ( + cd 8b && + + mkdir x && + mkdir y && + echo a1 >x/a && + echo b1 >x/b && + echo a2 >y/a && + echo b2 >y/b && + git add x y && + test_tick && + git commit -m "O" && + + git branch O && + git branch A && + git branch B && + + git checkout A && + echo e1 >x/e && + echo e2 >y/e && + git add x/e y/e && + test_tick && + git commit -m "A" && + + git checkout B && + git mv y z && + git mv x y && + test_tick && + git commit -m "B" + ) +' + +test_expect_success '8b-check: Dual-directory rename, one into the others way, with conflicting filenames' ' + ( + cd 8b && + + git checkout A^0 && + + git merge -s recursive B^0 && + + git ls-files -s >out && + test_line_count = 6 out && + git ls-files -u >out && + test_line_count = 0 out && + git ls-files -o >out && + test_line_count = 1 out && + + git rev-parse >actual \ + HEAD:y/a HEAD:y/b HEAD:z/a HEAD:z/b HEAD:x/e HEAD:y/e && + git rev-parse >expect \ + O:x/a O:x/b O:y/a O:y/b A:x/e A:y/e && + test_cmp expect actual + ) +' + +# Testcase 8c, rename+modify/delete +# (Related to testcases 5b and 8d) +# Commit O: z/{b,c,d} +# Commit A: y/{b,c} +# Commit B: z/{b,c,d_modified,e} +# Expected: y/{b,c,e}, CONFLICT(rename+modify/delete: x/d -> y/d or deleted) +# +# Note: This testcase doesn't present any concerns for me...until you +# compare it with testcases 5b and 8d. See notes in 8d for more +# details. + +test_expect_success '8c-setup: rename+modify/delete' ' + test_create_repo 8c && + ( + cd 8c && + + mkdir z && + echo b >z/b && + echo c >z/c && + test_seq 1 10 >z/d && + git add z && + test_tick && + git commit -m "O" && + + git branch O && + git branch A && + git branch B && + + git checkout A && + git rm z/d && + git mv z y && + test_tick && + git commit -m "A" && + + git checkout B && + echo 11 >z/d && + test_chmod +x z/d && + echo e >z/e && + git add z/d z/e && + test_tick && + git commit -m "B" + ) +' + +test_expect_failure '8c-check: rename+modify/delete' ' + ( + cd 8c && + + git checkout A^0 && + + test_must_fail git merge -s recursive B^0 >out && + test_i18ngrep "CONFLICT (rename/delete).* z/d.*y/d" out && + + git ls-files -s >out && + test_line_count = 4 out && + git ls-files -u >out && + test_line_count = 1 out && + git ls-files -o >out && + test_line_count = 1 out && + + git rev-parse >actual \ + :0:y/b :0:y/c :0:y/e :3:y/d && + git rev-parse >expect \ + O:z/b O:z/c B:z/e B:z/d && + test_cmp expect actual && + + test_must_fail git rev-parse :1:y/d && + test_must_fail git rev-parse :2:y/d && + git ls-files -s y/d | grep ^100755 && + test_path_is_file y/d + ) +' + +# Testcase 8d, rename/delete...or not? +# (Related to testcase 5b; these may appear slightly inconsistent to users; +# Also related to testcases 7d and 7e) +# Commit O: z/{b,c,d} +# Commit A: y/{b,c} +# Commit B: z/{b,c,d,e} +# Expected: y/{b,c,e} +# +# Note: It would also be somewhat reasonable to resolve this as +# y/{b,c,e}, CONFLICT(rename/delete: x/d -> y/d or deleted) +# The logic being that the only difference between this testcase and 8c +# is that there is no modification to d. That suggests that instead of a +# rename/modify vs. delete conflict, we should just have a rename/delete +# conflict, otherwise we are being inconsistent. +# +# However...as far as consistency goes, we didn't report a conflict for +# path d_1 in testcase 5b due to a different file being in the way. So, +# we seem to be forced to have cases where users can change things +# slightly and get what they may perceive as inconsistent results. It +# would be nice to avoid that, but I'm not sure I see how. +# +# In this case, I'm leaning towards: commit A was the one that deleted z/d +# and it did the rename of z to y, so the two "conflicts" (rename vs. +# delete) are both coming from commit A, which is illogical. Conflicts +# during merging are supposed to be about opposite sides doing things +# differently. + +test_expect_success '8d-setup: rename/delete...or not?' ' + test_create_repo 8d && + ( + cd 8d && + + mkdir z && + echo b >z/b && + echo c >z/c && + test_seq 1 10 >z/d && + git add z && + test_tick && + git commit -m "O" && + + git branch O && + git branch A && + git branch B && + + git checkout A && + git rm z/d && + git mv z y && + test_tick && + git commit -m "A" && + + git checkout B && + echo e >z/e && + git add z/e && + test_tick && + git commit -m "B" + ) +' + +test_expect_failure '8d-check: rename/delete...or not?' ' + ( + cd 8d && + + git checkout A^0 && + + git merge -s recursive B^0 && + + git ls-files -s >out && + test_line_count = 3 out && + + git rev-parse >actual \ + HEAD:y/b HEAD:y/c HEAD:y/e && + git rev-parse >expect \ + O:z/b O:z/c B:z/e && + test_cmp expect actual + ) +' + +# Testcase 8e, Both sides rename, one side adds to original directory +# Commit O: z/{b,c} +# Commit A: y/{b,c} +# Commit B: w/{b,c}, z/d +# +# Possible Resolutions: +# w/o dir-rename detection: z/d, CONFLICT(z/b -> y/b vs. w/b), +# CONFLICT(z/c -> y/c vs. w/c) +# Currently expected: y/d, CONFLICT(z/b -> y/b vs. w/b), +# CONFLICT(z/c -> y/c vs. w/c) +# Optimal: ?? +# +# Notes: In commit A, directory z got renamed to y. In commit B, directory z +# did NOT get renamed; the directory is still present; instead it is +# considered to have just renamed a subset of paths in directory z +# elsewhere. Therefore, the directory rename done in commit A to z/ +# applies to z/d and maps it to y/d. +# +# It's possible that users would get confused about this, but what +# should we do instead? Silently leaving at z/d seems just as bad or +# maybe even worse. Perhaps we could print a big warning about z/d +# and how we're moving to y/d in this case, but when I started thinking +# about the ramifications of doing that, I didn't know how to rule out +# that opening other weird edge and corner cases so I just punted. + +test_expect_success '8e-setup: Both sides rename, one side adds to original directory' ' + test_create_repo 8e && + ( + cd 8e && + + mkdir z && + echo b >z/b && + echo c >z/c && + git add z && + test_tick && + git commit -m "O" && + + git branch O && + git branch A && + git branch B && + + git checkout A && + git mv z y && + test_tick && + git commit -m "A" && + + git checkout B && + git mv z w && + mkdir z && + echo d >z/d && + git add z/d && + test_tick && + git commit -m "B" + ) +' + +test_expect_failure '8e-check: Both sides rename, one side adds to original directory' ' + ( + cd 8e && + + git checkout A^0 && + + test_must_fail git merge -s recursive B^0 >out 2>err && + test_i18ngrep CONFLICT.*rename/rename.*z/c.*y/c.*w/c out && + test_i18ngrep CONFLICT.*rename/rename.*z/b.*y/b.*w/b out && + + git ls-files -s >out && + test_line_count = 7 out && + git ls-files -u >out && + test_line_count = 6 out && + git ls-files -o >out && + test_line_count = 2 out && + + git rev-parse >actual \ + :1:z/b :2:y/b :3:w/b :1:z/c :2:y/c :3:w/c :0:y/d && + git rev-parse >expect \ + O:z/b O:z/b O:z/b O:z/c O:z/c O:z/c B:z/d && + test_cmp expect actual && + + git hash-object >actual \ + y/b w/b y/c w/c && + git rev-parse >expect \ + O:z/b O:z/b O:z/c O:z/c && + test_cmp expect actual && + + test_path_is_missing z/b && + test_path_is_missing z/c + ) +' + test_done -- 2.17.0.290.ge988e9ce2a