From c04ba51739a7771583e31966adb7c472980f3fc3 Mon Sep 17 00:00:00 2001 From: Elijah Newren Date: Thu, 19 Apr 2018 10:58:19 -0700 Subject: t6046: testcases checking whether updates can be skipped in a merge Add several tests checking whether updates can be skipped in a merge. Also add several similar testcases for where updates cannot be skipped in a merge to make sure that we skip if and only if we should. In particular: * Testcase 1a (particularly 1a-check-L) would have pointed out the problem Linus has been dealing with for year with his merges[1]. * Testcase 2a (particularly 2a-check-L) would have pointed out the problem with my directory-rename-series before it broke master[2]. * Testcases 3[ab] (particularly 3a-check-L) provide a simpler testcase than 12b of t6043 making that one easier to understand. * There are several complementary testcases to make sure we're not just fixing those particular issues while regressing in the opposite direction. * There are also a pair of tests for the special case when a merge results in a skippable update AND the user has dirty modifications to the path. [1] https://public-inbox.org/git/CA+55aFzLZ3UkG5svqZwSnhNk75=fXJRkvU1m_RHBG54NOoaZPA@mail.gmail.com/ [2] https://public-inbox.org/git/xmqqmuya43cs.fsf@gitster-ct.c.googlers.com/ Signed-off-by: Elijah Newren Signed-off-by: Junio C Hamano diff --git a/t/t6046-merge-skip-unneeded-updates.sh b/t/t6046-merge-skip-unneeded-updates.sh new file mode 100755 index 0000000..a0f482e --- /dev/null +++ b/t/t6046-merge-skip-unneeded-updates.sh @@ -0,0 +1,761 @@ +#!/bin/sh + +test_description="merge cases" + +# The setup for all of them, pictorially, is: +# +# A +# o +# / \ +# O o ? +# \ / +# o +# B +# +# To help make it easier to follow the flow of tests, they have been +# divided into sections and each test will start with a quick explanation +# of what commits O, A, and B contain. +# +# Notation: +# z/{b,c} means files z/b and z/c both exist +# x/d_1 means file x/d exists with content d1. (Purpose of the +# underscore notation is to differentiate different +# files that might be renamed into each other's paths.) + +. ./test-lib.sh + + +########################################################################### +# SECTION 1: Cases involving no renames (one side has subset of changes of +# the other side) +########################################################################### + +# Testcase 1a, Changes on A, subset of changes on B +# Commit O: b_1 +# Commit A: b_2 +# Commit B: b_3 +# Expected: b_2 + +test_expect_success '1a-setup: Modify(A)/Modify(B), change on B subset of A' ' + test_create_repo 1a && + ( + cd 1a && + + test_write_lines 1 2 3 4 5 6 7 8 9 10 >b && + git add b && + test_tick && + git commit -m "O" && + + git branch O && + git branch A && + git branch B && + + git checkout A && + test_write_lines 1 2 3 4 5 5.5 6 7 8 9 10 10.5 >b && + git add b && + test_tick && + git commit -m "A" && + + git checkout B && + test_write_lines 1 2 3 4 5 5.5 6 7 8 9 10 >b && + git add b && + test_tick && + git commit -m "B" + ) +' + +test_expect_failure '1a-check-L: Modify(A)/Modify(B), change on B subset of A' ' + test_when_finished "git -C 1a reset --hard" && + test_when_finished "git -C 1a clean -fd" && + ( + cd 1a && + + git checkout A^0 && + + test-tool chmtime =31337 b && + test-tool chmtime -v +0 b >expected-mtime && + + GIT_MERGE_VERBOSITY=3 git merge -s recursive B^0 >out 2>err && + + test_i18ngrep "Skipped b" out && + test_must_be_empty err && + + test-tool chmtime -v +0 b >actual-mtime && + test_cmp expected-mtime actual-mtime && + + git ls-files -s >index_files && + test_line_count = 1 index_files && + + git rev-parse >actual HEAD:b && + git rev-parse >expect A:b && + test_cmp expect actual && + + git hash-object b >actual && + git rev-parse A:b >expect && + test_cmp expect actual + ) +' + +test_expect_success '1a-check-R: Modify(A)/Modify(B), change on B subset of A' ' + test_when_finished "git -C 1a reset --hard" && + test_when_finished "git -C 1a clean -fd" && + ( + cd 1a && + + git checkout B^0 && + + GIT_MERGE_VERBOSITY=3 git merge -s recursive A^0 >out 2>err && + + test_i18ngrep "Auto-merging b" out && + test_must_be_empty err && + + git ls-files -s >index_files && + test_line_count = 1 index_files && + + git rev-parse >actual HEAD:b && + git rev-parse >expect A:b && + test_cmp expect actual && + + git hash-object b >actual && + git rev-parse A:b >expect && + test_cmp expect actual + ) +' + + +########################################################################### +# SECTION 2: Cases involving basic renames +########################################################################### + +# Testcase 2a, Changes on A, rename on B +# Commit O: b_1 +# Commit A: b_2 +# Commit B: c_1 +# Expected: c_2 + +test_expect_success '2a-setup: Modify(A)/rename(B)' ' + test_create_repo 2a && + ( + cd 2a && + + test_seq 1 10 >b && + git add b && + test_tick && + git commit -m "O" && + + git branch O && + git branch A && + git branch B && + + git checkout A && + test_seq 1 11 >b && + git add b && + test_tick && + git commit -m "A" && + + git checkout B && + git mv b c && + test_tick && + git commit -m "B" + ) +' + +test_expect_failure '2a-check-L: Modify/rename, merge into modify side' ' + test_when_finished "git -C 2a reset --hard" && + test_when_finished "git -C 2a clean -fd" && + ( + cd 2a && + + git checkout A^0 && + + GIT_MERGE_VERBOSITY=3 git merge -s recursive B^0 >out 2>err && + + test_i18ngrep ! "Skipped c" out && + test_must_be_empty err && + + git ls-files -s >index_files && + test_line_count = 1 index_files && + + git rev-parse >actual HEAD:c && + git rev-parse >expect A:b && + test_cmp expect actual && + + git hash-object c >actual && + git rev-parse A:b >expect && + test_cmp expect actual && + + test_must_fail git rev-parse HEAD:b && + test_path_is_missing b + ) +' + +test_expect_success '2a-check-R: Modify/rename, merge into rename side' ' + test_when_finished "git -C 2a reset --hard" && + test_when_finished "git -C 2a clean -fd" && + ( + cd 2a && + + git checkout B^0 && + + GIT_MERGE_VERBOSITY=3 git merge -s recursive A^0 >out 2>err && + + test_i18ngrep ! "Skipped c" out && + test_must_be_empty err && + + git ls-files -s >index_files && + test_line_count = 1 index_files && + + git rev-parse >actual HEAD:c && + git rev-parse >expect A:b && + test_cmp expect actual && + + git hash-object c >actual && + git rev-parse A:b >expect && + test_cmp expect actual && + + test_must_fail git rev-parse HEAD:b && + test_path_is_missing b + ) +' + +# Testcase 2b, Changed and renamed on A, subset of changes on B +# Commit O: b_1 +# Commit A: c_2 +# Commit B: b_3 +# Expected: c_2 + +test_expect_success '2b-setup: Rename+Mod(A)/Mod(B), B mods subset of A' ' + test_create_repo 2b && + ( + cd 2b && + + test_write_lines 1 2 3 4 5 6 7 8 9 10 >b && + git add b && + test_tick && + git commit -m "O" && + + git branch O && + git branch A && + git branch B && + + git checkout A && + test_write_lines 1 2 3 4 5 5.5 6 7 8 9 10 10.5 >b && + git add b && + git mv b c && + test_tick && + git commit -m "A" && + + git checkout B && + test_write_lines 1 2 3 4 5 5.5 6 7 8 9 10 >b && + git add b && + test_tick && + git commit -m "B" + ) +' + +test_expect_success '2b-check-L: Rename+Mod(A)/Mod(B), B mods subset of A' ' + test_when_finished "git -C 2b reset --hard" && + test_when_finished "git -C 2b clean -fd" && + ( + cd 2b && + + git checkout A^0 && + + test-tool chmtime =31337 c && + test-tool chmtime -v +0 c >expected-mtime && + + GIT_MERGE_VERBOSITY=3 git merge -s recursive B^0 >out 2>err && + + test_i18ngrep "Skipped c" out && + test_must_be_empty err && + + test-tool chmtime -v +0 c >actual-mtime && + test_cmp expected-mtime actual-mtime && + + git ls-files -s >index_files && + test_line_count = 1 index_files && + + git rev-parse >actual HEAD:c && + git rev-parse >expect A:c && + test_cmp expect actual && + + git hash-object c >actual && + git rev-parse A:c >expect && + test_cmp expect actual && + + test_must_fail git rev-parse HEAD:b && + test_path_is_missing b + ) +' + +test_expect_success '2b-check-R: Rename+Mod(A)/Mod(B), B mods subset of A' ' + test_when_finished "git -C 2b reset --hard" && + test_when_finished "git -C 2b clean -fd" && + ( + cd 2b && + + git checkout B^0 && + + GIT_MERGE_VERBOSITY=3 git merge -s recursive A^0 >out 2>err && + + test_i18ngrep "Auto-merging c" out && + test_must_be_empty err && + + git ls-files -s >index_files && + test_line_count = 1 index_files && + + git rev-parse >actual HEAD:c && + git rev-parse >expect A:c && + test_cmp expect actual && + + git hash-object c >actual && + git rev-parse A:c >expect && + test_cmp expect actual && + + test_must_fail git rev-parse HEAD:b && + test_path_is_missing b + ) +' + +# Testcase 2c, Changes on A, rename on B +# Commit O: b_1 +# Commit A: b_2, c_3 +# Commit B: c_1 +# Expected: rename/add conflict c_2 vs c_3 +# +# NOTE: Since A modified b_1->b_2, and B renamed b_1->c_1, the threeway +# merge of those files should result in c_2. We then should have a +# rename/add conflict between c_2 and c_3. However, if we note in +# merge_content() that A had the right contents (b_2 has same +# contents as c_2, just at a different name), and that A had the +# right path present (c_3 existed) and thus decides that it can +# skip the update, then we're in trouble. This test verifies we do +# not make that particular mistake. + +test_expect_success '2c-setup: Modify b & add c VS rename b->c' ' + test_create_repo 2c && + ( + cd 2c && + + test_seq 1 10 >b && + git add b && + test_tick && + git commit -m "O" && + + git branch O && + git branch A && + git branch B && + + git checkout A && + test_seq 1 11 >b && + echo whatever >c && + git add b c && + test_tick && + git commit -m "A" && + + git checkout B && + git mv b c && + test_tick && + git commit -m "B" + ) +' + +test_expect_failure '2c-check: Modify b & add c VS rename b->c' ' + ( + cd 2c && + + git checkout A^0 && + + GIT_MERGE_VERBOSITY=3 test_must_fail git merge -s recursive B^0 >out 2>err && + + test_i18ngrep "CONFLICT (rename/add): Rename b->c" out && + test_i18ngrep ! "Skipped c" out && + test_must_be_empty err + + # FIXME: rename/add conflicts are horribly broken right now; + # when I get back to my patch series fixing it and + # rename/rename(2to1) conflicts to bring them in line with + # how add/add conflicts behave, then checks like the below + # could be added. But that patch series is waiting until + # the rename-directory-detection series lands, which this + # is part of. And in the mean time, I do not want to further + # enforce broken behavior. So for now, the main test is the + # one above that err is an empty file. + + #git ls-files -s >index_files && + #test_line_count = 2 index_files && + + #git rev-parse >actual :2:c :3:c && + #git rev-parse >expect A:b A:c && + #test_cmp expect actual && + + #git cat-file -p A:b >>merged && + #git cat-file -p A:c >>merge-me && + #>empty && + #test_must_fail git merge-file \ + # -L "Temporary merge branch 1" \ + # -L "" \ + # -L "Temporary merge branch 2" \ + # merged empty merge-me && + #sed -e "s/^\([<=>]\)/\1\1\1/" merged >merged-internal && + + #git hash-object c >actual && + #git hash-object merged-internal >expect && + #test_cmp expect actual && + + #test_path_is_missing b + ) +' + + +########################################################################### +# SECTION 3: Cases involving directory renames +# +# NOTE: +# Directory renames only apply when one side renames a directory, and the +# other side adds or renames a path into that directory. Applying the +# directory rename to that new path creates a new pathname that didn't +# exist on either side of history. Thus, it is impossible for the +# merge contents to already be at the right path, so all of these checks +# exist just to make sure that updates are not skipped. +########################################################################### + +# Testcase 3a, Change + rename into dir foo on A, dir rename foo->bar on B +# Commit O: bq_1, foo/whatever +# Commit A: foo/{bq_2, whatever} +# Commit B: bq_1, bar/whatever +# Expected: bar/{bq_2, whatever} + +test_expect_success '3a-setup: bq_1->foo/bq_2 on A, foo/->bar/ on B' ' + test_create_repo 3a && + ( + cd 3a && + + mkdir foo && + test_seq 1 10 >bq && + test_write_lines a b c d e f g h i j k >foo/whatever && + git add bq foo/whatever && + test_tick && + git commit -m "O" && + + git branch O && + git branch A && + git branch B && + + git checkout A && + test_seq 1 11 >bq && + git add bq && + git mv bq foo/ && + test_tick && + git commit -m "A" && + + git checkout B && + git mv foo/ bar/ && + test_tick && + git commit -m "B" + ) +' + +test_expect_failure '3a-check-L: bq_1->foo/bq_2 on A, foo/->bar/ on B' ' + test_when_finished "git -C 3a reset --hard" && + test_when_finished "git -C 3a clean -fd" && + ( + cd 3a && + + git checkout A^0 && + + GIT_MERGE_VERBOSITY=3 git merge -s recursive B^0 >out 2>err && + + test_i18ngrep ! "Skipped bar/bq" out && + test_must_be_empty err && + + git ls-files -s >index_files && + test_line_count = 2 index_files && + + git rev-parse >actual HEAD:bar/bq HEAD:bar/whatever && + git rev-parse >expect A:foo/bq A:foo/whatever && + test_cmp expect actual && + + git hash-object bar/bq bar/whatever >actual && + git rev-parse A:foo/bq A:foo/whatever >expect && + test_cmp expect actual && + + test_must_fail git rev-parse HEAD:bq HEAD:foo/bq && + test_path_is_missing bq foo/bq foo/whatever + ) +' + +test_expect_success '3a-check-R: bq_1->foo/bq_2 on A, foo/->bar/ on B' ' + test_when_finished "git -C 3a reset --hard" && + test_when_finished "git -C 3a clean -fd" && + ( + cd 3a && + + git checkout B^0 && + + GIT_MERGE_VERBOSITY=3 git merge -s recursive A^0 >out 2>err && + + test_i18ngrep ! "Skipped bar/bq" out && + test_must_be_empty err && + + git ls-files -s >index_files && + test_line_count = 2 index_files && + + git rev-parse >actual HEAD:bar/bq HEAD:bar/whatever && + git rev-parse >expect A:foo/bq A:foo/whatever && + test_cmp expect actual && + + git hash-object bar/bq bar/whatever >actual && + git rev-parse A:foo/bq A:foo/whatever >expect && + test_cmp expect actual && + + test_must_fail git rev-parse HEAD:bq HEAD:foo/bq && + test_path_is_missing bq foo/bq foo/whatever + ) +' + +# Testcase 3b, rename into dir foo on A, dir rename foo->bar + change on B +# Commit O: bq_1, foo/whatever +# Commit A: foo/{bq_1, whatever} +# Commit B: bq_2, bar/whatever +# Expected: bar/{bq_2, whatever} + +test_expect_success '3b-setup: bq_1->foo/bq_2 on A, foo/->bar/ on B' ' + test_create_repo 3b && + ( + cd 3b && + + mkdir foo && + test_seq 1 10 >bq && + test_write_lines a b c d e f g h i j k >foo/whatever && + git add bq foo/whatever && + test_tick && + git commit -m "O" && + + git branch O && + git branch A && + git branch B && + + git checkout A && + git mv bq foo/ && + test_tick && + git commit -m "A" && + + git checkout B && + test_seq 1 11 >bq && + git add bq && + git mv foo/ bar/ && + test_tick && + git commit -m "B" + ) +' + +test_expect_success '3b-check-L: bq_1->foo/bq_2 on A, foo/->bar/ on B' ' + test_when_finished "git -C 3b reset --hard" && + test_when_finished "git -C 3b clean -fd" && + ( + cd 3b && + + git checkout A^0 && + + GIT_MERGE_VERBOSITY=3 git merge -s recursive B^0 >out 2>err && + + test_i18ngrep ! "Skipped bar/bq" out && + test_must_be_empty err && + + git ls-files -s >index_files && + test_line_count = 2 index_files && + + git rev-parse >actual HEAD:bar/bq HEAD:bar/whatever && + git rev-parse >expect B:bq A:foo/whatever && + test_cmp expect actual && + + git hash-object bar/bq bar/whatever >actual && + git rev-parse B:bq A:foo/whatever >expect && + test_cmp expect actual && + + test_must_fail git rev-parse HEAD:bq HEAD:foo/bq && + test_path_is_missing bq foo/bq foo/whatever + ) +' + +test_expect_failure '3b-check-R: bq_1->foo/bq_2 on A, foo/->bar/ on B' ' + test_when_finished "git -C 3b reset --hard" && + test_when_finished "git -C 3b clean -fd" && + ( + cd 3b && + + git checkout B^0 && + + GIT_MERGE_VERBOSITY=3 git merge -s recursive A^0 >out 2>err && + + test_i18ngrep ! "Skipped bar/bq" out && + test_must_be_empty err && + + git ls-files -s >index_files && + test_line_count = 2 index_files && + + git rev-parse >actual HEAD:bar/bq HEAD:bar/whatever && + git rev-parse >expect B:bq A:foo/whatever && + test_cmp expect actual && + + git hash-object bar/bq bar/whatever >actual && + git rev-parse B:bq A:foo/whatever >expect && + test_cmp expect actual && + + test_must_fail git rev-parse HEAD:bq HEAD:foo/bq && + test_path_is_missing bq foo/bq foo/whatever + ) +' + +########################################################################### +# SECTION 4: Cases involving dirty changes +########################################################################### + +# Testcase 4a, Changed on A, subset of changes on B, locally modified +# Commit O: b_1 +# Commit A: b_2 +# Commit B: b_3 +# Working copy: b_4 +# Expected: b_2 for merge, b_4 in working copy + +test_expect_success '4a-setup: Change on A, change on B subset of A, dirty mods present' ' + test_create_repo 4a && + ( + cd 4a && + + test_write_lines 1 2 3 4 5 6 7 8 9 10 >b && + git add b && + test_tick && + git commit -m "O" && + + git branch O && + git branch A && + git branch B && + + git checkout A && + test_write_lines 1 2 3 4 5 5.5 6 7 8 9 10 10.5 >b && + git add b && + test_tick && + git commit -m "A" && + + git checkout B && + test_write_lines 1 2 3 4 5 5.5 6 7 8 9 10 >b && + git add b && + test_tick && + git commit -m "B" + ) +' + +# NOTE: For as long as we continue using unpack_trees() without index_only +# set to true, it will error out on a case like this claiming the the locally +# modified file would be overwritten by the merge. Getting this testcase +# correct requires doing the merge in-memory first, then realizing that no +# updates to the file are necessary, and thus that we can just leave the path +# alone. +test_expect_failure '4a-check: Change on A, change on B subset of A, dirty mods present' ' + test_when_finished "git -C 4a reset --hard" && + test_when_finished "git -C 4a clean -fd" && + ( + cd 4a && + + git checkout A^0 && + echo "File rewritten" >b && + + test-tool chmtime =31337 b && + test-tool chmtime -v +0 b >expected-mtime && + + GIT_MERGE_VERBOSITY=3 git merge -s recursive B^0 >out 2>err && + + test_i18ngrep "Skipped b" out && + test_must_be_empty err && + + test-tool chmtime -v +0 b >actual-mtime && + test_cmp expected-mtime actual-mtime && + + git ls-files -s >index_files && + test_line_count = 1 index_files && + + git rev-parse >actual :0:b && + git rev-parse >expect A:b && + test_cmp expect actual && + + git hash-object b >actual && + echo "File rewritten" | git hash-object --stdin >expect && + test_cmp expect actual + ) +' + +# Testcase 4b, Changed+renamed on A, subset of changes on B, locally modified +# Commit O: b_1 +# Commit A: c_2 +# Commit B: b_3 +# Working copy: c_4 +# Expected: c_2 + +test_expect_success '4b-setup: Rename+Mod(A)/Mod(B), change on B subset of A, dirty mods present' ' + test_create_repo 4b && + ( + cd 4b && + + test_write_lines 1 2 3 4 5 6 7 8 9 10 >b && + git add b && + test_tick && + git commit -m "O" && + + git branch O && + git branch A && + git branch B && + + git checkout A && + test_write_lines 1 2 3 4 5 5.5 6 7 8 9 10 10.5 >b && + git add b && + git mv b c && + test_tick && + git commit -m "A" && + + git checkout B && + test_write_lines 1 2 3 4 5 5.5 6 7 8 9 10 >b && + git add b && + test_tick && + git commit -m "B" + ) +' + +test_expect_success '4b-check: Rename+Mod(A)/Mod(B), change on B subset of A, dirty mods present' ' + test_when_finished "git -C 4b reset --hard" && + test_when_finished "git -C 4b clean -fd" && + ( + cd 4b && + + git checkout A^0 && + echo "File rewritten" >c && + + test-tool chmtime =31337 c && + test-tool chmtime -v +0 c >expected-mtime && + + GIT_MERGE_VERBOSITY=3 git merge -s recursive B^0 >out 2>err && + + test_i18ngrep "Skipped c" out && + test_must_be_empty err && + + test-tool chmtime -v +0 c >actual-mtime && + test_cmp expected-mtime actual-mtime && + + git ls-files -s >index_files && + test_line_count = 1 index_files && + + git rev-parse >actual :0:c && + git rev-parse >expect A:c && + test_cmp expect actual && + + git hash-object c >actual && + echo "File rewritten" | git hash-object --stdin >expect && + test_cmp expect actual && + + test_must_fail git rev-parse HEAD:b && + test_path_is_missing b + ) +' + +test_done -- cgit v0.10.2-6-g49f6