merge(third_party/git): Merge squashed git subtree at v2.23.0 r/373

Merge commit '1b593e1ea4d2af0f6444d9a7788d5d99abd6fde5' as 'third_party/git'

1 files changed, 455 insertions, 0 deletions

diff --git a/third_party/git/t/t7405-submodule-merge.sh b/third_party/git/t/t7405-submodule-merge.sh
new file mode 100755
index 000000000000..aa33978ed286
--- /dev/null
+++ b/third_party/git/t/t7405-submodule-merge.sh
@@ -0,0 +1,455 @@
+#!/bin/sh
+
+test_description='merging with submodules'
+
+. ./test-lib.sh
+
+#
+# history
+#
+#        a --- c
+#      /   \ /
+# root      X
+#      \   / \
+#        b --- d
+#
+
+test_expect_success setup '
+
+	mkdir sub &&
+	(cd sub &&
+	 git init &&
+	 echo original > file &&
+	 git add file &&
+	 test_tick &&
+	 git commit -m sub-root) &&
+	git add sub &&
+	test_tick &&
+	git commit -m root &&
+
+	git checkout -b a master &&
+	(cd sub &&
+	 echo A > file &&
+	 git add file &&
+	 test_tick &&
+	 git commit -m sub-a) &&
+	git add sub &&
+	test_tick &&
+	git commit -m a &&
+
+	git checkout -b b master &&
+	(cd sub &&
+	 echo B > file &&
+	 git add file &&
+	 test_tick &&
+	 git commit -m sub-b) &&
+	git add sub &&
+	test_tick &&
+	git commit -m b &&
+
+	git checkout -b c a &&
+	git merge -s ours b &&
+
+	git checkout -b d b &&
+	git merge -s ours a
+'
+
+# History setup
+#
+#             b
+#           /   \
+#  init -- a     d
+#    \      \   /
+#     g       c
+#
+# a in the main repository records to sub-a in the submodule and
+# analogous b and c. d should be automatically found by merging c into
+# b in the main repository.
+test_expect_success 'setup for merge search' '
+	mkdir merge-search &&
+	(cd merge-search &&
+	git init &&
+	mkdir sub &&
+	(cd sub &&
+	 git init &&
+	 echo "file-a" > file-a &&
+	 git add file-a &&
+	 git commit -m "sub-a" &&
+	 git branch sub-a) &&
+	git commit --allow-empty -m init &&
+	git branch init &&
+	git add sub &&
+	git commit -m "a" &&
+	git branch a &&
+
+	git checkout -b b &&
+	(cd sub &&
+	 git checkout -b sub-b &&
+	 echo "file-b" > file-b &&
+	 git add file-b &&
+	 git commit -m "sub-b") &&
+	git commit -a -m "b" &&
+
+	git checkout -b c a &&
+	(cd sub &&
+	 git checkout -b sub-c sub-a &&
+	 echo "file-c" > file-c &&
+	 git add file-c &&
+	 git commit -m "sub-c") &&
+	git commit -a -m "c" &&
+
+	git checkout -b d a &&
+	(cd sub &&
+	 git checkout -b sub-d sub-b &&
+	 git merge sub-c) &&
+	git commit -a -m "d" &&
+	git branch test b &&
+
+	git checkout -b g init &&
+	(cd sub &&
+	 git checkout -b sub-g sub-c) &&
+	git add sub &&
+	git commit -a -m "g")
+'
+
+test_expect_success 'merge with one side as a fast-forward of the other' '
+	(cd merge-search &&
+	 git checkout -b test-forward b &&
+	 git merge d &&
+	 git ls-tree test-forward sub | cut -f1 | cut -f3 -d" " > actual &&
+	 (cd sub &&
+	  git rev-parse sub-d > ../expect) &&
+	 test_cmp expect actual)
+'
+
+test_expect_success 'merging should conflict for non fast-forward' '
+	(cd merge-search &&
+	 git checkout -b test-nonforward b &&
+	 (cd sub &&
+	  git rev-parse sub-d > ../expect) &&
+	 test_must_fail git merge c 2> actual  &&
+	 grep $(cat expect) actual > /dev/null &&
+	 git reset --hard)
+'
+
+test_expect_success 'merging should fail for ambiguous common parent' '
+	(cd merge-search &&
+	git checkout -b test-ambiguous b &&
+	(cd sub &&
+	 git checkout -b ambiguous sub-b &&
+	 git merge sub-c &&
+	 git rev-parse sub-d > ../expect1 &&
+	 git rev-parse ambiguous > ../expect2) &&
+	test_must_fail git merge c 2> actual &&
+	grep $(cat expect1) actual > /dev/null &&
+	grep $(cat expect2) actual > /dev/null &&
+	git reset --hard)
+'
+
+# in a situation like this
+#
+# submodule tree:
+#
+#    sub-a --- sub-b --- sub-d
+#
+# main tree:
+#
+#    e (sub-a)
+#   /
+#  bb (sub-b)
+#   \
+#    f (sub-d)
+#
+# A merge between e and f should fail because one of the submodule
+# commits (sub-a) does not descend from the submodule merge-base (sub-b).
+#
+test_expect_success 'merging should fail for changes that are backwards' '
+	(cd merge-search &&
+	git checkout -b bb a &&
+	(cd sub &&
+	 git checkout sub-b) &&
+	git commit -a -m "bb" &&
+
+	git checkout -b e bb &&
+	(cd sub &&
+	 git checkout sub-a) &&
+	git commit -a -m "e" &&
+
+	git checkout -b f bb &&
+	(cd sub &&
+	 git checkout sub-d) &&
+	git commit -a -m "f" &&
+
+	git checkout -b test-backward e &&
+	test_must_fail git merge f)
+'
+
+
+# Check that the conflicting submodule is detected when it is
+# in the common ancestor. status should be 'U00...00"
+test_expect_success 'git submodule status should display the merge conflict properly with merge base' '
+       (cd merge-search &&
+       cat >.gitmodules <<EOF &&
+[submodule "sub"]
+       path = sub
+       url = $TRASH_DIRECTORY/sub
+EOF
+       cat >expect <<EOF &&
+U0000000000000000000000000000000000000000 sub
+EOF
+       git submodule status > actual &&
+       test_cmp expect actual &&
+	git reset --hard)
+'
+
+# Check that the conflicting submodule is detected when it is
+# not in the common ancestor. status should be 'U00...00"
+test_expect_success 'git submodule status should display the merge conflict properly without merge-base' '
+       (cd merge-search &&
+	git checkout -b test-no-merge-base g &&
+	test_must_fail git merge b &&
+       cat >.gitmodules <<EOF &&
+[submodule "sub"]
+       path = sub
+       url = $TRASH_DIRECTORY/sub
+EOF
+       cat >expect <<EOF &&
+U0000000000000000000000000000000000000000 sub
+EOF
+       git submodule status > actual &&
+       test_cmp expect actual &&
+       git reset --hard)
+'
+
+
+test_expect_success 'merging with a modify/modify conflict between merge bases' '
+	git reset --hard HEAD &&
+	git checkout -b test2 c &&
+	git merge d
+'
+
+# canonical criss-cross history in top and submodule
+test_expect_success 'setup for recursive merge with submodule' '
+	mkdir merge-recursive &&
+	(cd merge-recursive &&
+	 git init &&
+	 mkdir sub &&
+	 (cd sub &&
+	  git init &&
+	  test_commit a &&
+	  git checkout -b sub-b master &&
+	  test_commit b &&
+	  git checkout -b sub-c master &&
+	  test_commit c &&
+	  git checkout -b sub-bc sub-b &&
+	  git merge sub-c &&
+	  git checkout -b sub-cb sub-c &&
+	  git merge sub-b &&
+	  git checkout master) &&
+	 git add sub &&
+	 git commit -m a &&
+	 git checkout -b top-b master &&
+	 (cd sub && git checkout sub-b) &&
+	 git add sub &&
+	 git commit -m b &&
+	 git checkout -b top-c master &&
+	 (cd sub && git checkout sub-c) &&
+	 git add sub &&
+	 git commit -m c &&
+	 git checkout -b top-bc top-b &&
+	 git merge -s ours --no-commit top-c &&
+	 (cd sub && git checkout sub-bc) &&
+	 git add sub &&
+	 git commit -m bc &&
+	 git checkout -b top-cb top-c &&
+	 git merge -s ours --no-commit top-b &&
+	 (cd sub && git checkout sub-cb) &&
+	 git add sub &&
+	 git commit -m cb)
+'
+
+# merge should leave submodule unmerged in index
+test_expect_success 'recursive merge with submodule' '
+	(cd merge-recursive &&
+	 test_must_fail git merge top-bc &&
+	 echo "160000 $(git rev-parse top-cb:sub) 2	sub" > expect2 &&
+	 echo "160000 $(git rev-parse top-bc:sub) 3	sub" > expect3 &&
+	 git ls-files -u > actual &&
+	 grep "$(cat expect2)" actual > /dev/null &&
+	 grep "$(cat expect3)" actual > /dev/null)
+'
+
+# File/submodule conflict
+#   Commit O: <empty>
+#   Commit A: path (submodule)
+#   Commit B: path
+#   Expected: path/ is submodule and file contents for B's path are somewhere
+
+test_expect_success 'setup file/submodule conflict' '
+	test_create_repo file-submodule &&
+	(
+		cd file-submodule &&
+
+		git commit --allow-empty -m O &&
+
+		git branch A &&
+		git branch B &&
+
+		git checkout B &&
+		echo content >path &&
+		git add path &&
+		git commit -m B &&
+
+		git checkout A &&
+		test_create_repo path &&
+		test_commit -C path world &&
+		git submodule add ./path &&
+		git commit -m A
+	)
+'
+
+test_expect_failure 'file/submodule conflict' '
+	test_when_finished "git -C file-submodule reset --hard" &&
+	(
+		cd file-submodule &&
+
+		git checkout A^0 &&
+		test_must_fail git merge B^0 &&
+
+		git ls-files -s >out &&
+		test_line_count = 3 out &&
+		git ls-files -u >out &&
+		test_line_count = 2 out &&
+
+		# path/ is still a submodule
+		test_path_is_dir path/.git &&
+
+		# There is a submodule at "path", so B:path cannot be written
+		# there.  We expect it to be written somewhere in the same
+		# directory, though, so just grep for its content in all
+		# files, and ignore "grep: path: Is a directory" message
+		echo Checking if contents from B:path showed up anywhere &&
+		grep -q content * 2>/dev/null
+	)
+'
+
+test_expect_success 'file/submodule conflict; merge --abort works afterward' '
+	test_when_finished "git -C file-submodule reset --hard" &&
+	(
+		cd file-submodule &&
+
+		git checkout A^0 &&
+		test_must_fail git merge B^0 >out 2>err &&
+
+		test_path_is_file .git/MERGE_HEAD &&
+		git merge --abort
+	)
+'
+
+# Directory/submodule conflict
+#   Commit O: <empty>
+#   Commit A: path (submodule), with sole tracked file named 'world'
+#   Commit B1: path/file
+#   Commit B2: path/world
+#
+#   Expected from merge of A & B1:
+#     Contents under path/ from commit B1 are renamed elsewhere; we do not
+#     want to write files from one of our tracked directories into a submodule
+#
+#   Expected from merge of A & B2:
+#     Similar to last merge, but with a slight twist: we don't want paths
+#     under the submodule to be treated as untracked or in the way.
+
+test_expect_success 'setup directory/submodule conflict' '
+	test_create_repo directory-submodule &&
+	(
+		cd directory-submodule &&
+
+		git commit --allow-empty -m O &&
+
+		git branch A &&
+		git branch B1 &&
+		git branch B2 &&
+
+		git checkout B1 &&
+		mkdir path &&
+		echo contents >path/file &&
+		git add path/file &&
+		git commit -m B1 &&
+
+		git checkout B2 &&
+		mkdir path &&
+		echo contents >path/world &&
+		git add path/world &&
+		git commit -m B2 &&
+
+		git checkout A &&
+		test_create_repo path &&
+		test_commit -C path hello world &&
+		git submodule add ./path &&
+		git commit -m A
+	)
+'
+
+test_expect_failure 'directory/submodule conflict; keep submodule clean' '
+	test_when_finished "git -C directory-submodule reset --hard" &&
+	(
+		cd directory-submodule &&
+
+		git checkout A^0 &&
+		test_must_fail git merge B1^0 &&
+
+		git ls-files -s >out &&
+		test_line_count = 3 out &&
+		git ls-files -u >out &&
+		test_line_count = 1 out &&
+
+		# path/ is still a submodule
+		test_path_is_dir path/.git &&
+
+		echo Checking if contents from B1:path/file showed up &&
+		# Would rather use grep -r, but that is GNU extension...
+		git ls-files -co | xargs grep -q contents 2>/dev/null &&
+
+		# However, B1:path/file should NOT have shown up at path/file,
+		# because we should not write into the submodule
+		test_path_is_missing path/file
+	)
+'
+
+test_expect_failure !FAIL_PREREQS 'directory/submodule conflict; should not treat submodule files as untracked or in the way' '
+	test_when_finished "git -C directory-submodule/path reset --hard" &&
+	test_when_finished "git -C directory-submodule reset --hard" &&
+	(
+		cd directory-submodule &&
+
+		git checkout A^0 &&
+		test_must_fail git merge B2^0 >out 2>err &&
+
+		# We do not want files within the submodule to prevent the
+		# merge from starting; we should not be writing to such paths
+		# anyway.
+		test_i18ngrep ! "refusing to lose untracked file at" err
+	)
+'
+
+test_expect_failure 'directory/submodule conflict; merge --abort works afterward' '
+	test_when_finished "git -C directory-submodule/path reset --hard" &&
+	test_when_finished "git -C directory-submodule reset --hard" &&
+	(
+		cd directory-submodule &&
+
+		git checkout A^0 &&
+		test_must_fail git merge B2^0 &&
+		test_path_is_file .git/MERGE_HEAD &&
+
+		# merge --abort should succeed, should clear .git/MERGE_HEAD,
+		# and should not leave behind any conflicted files
+		git merge --abort &&
+		test_path_is_missing .git/MERGE_HEAD &&
+		git ls-files -u >conflicts &&
+		test_must_be_empty conflicts
+	)
+'
+
+test_done