merge tests: expect improved directory/file conflict handling in ort

merge-recursive.c is built on the idea of running unpack_trees() and
then "doing minor touch-ups" to get the result.  Unfortunately,
unpack_trees() was run in an update-as-it-goes mode, leading
merge-recursive.c to follow suit and end up with an immediate evaluation
and fix-it-up-as-you-go design.  Some things like directory/file
conflicts are not well representable in the index data structure, and
required special extra code to handle.  But then when it was discovered
that rename/delete conflicts could also be involved in directory/file
conflicts, the special directory/file conflict handling code had to be
copied to the rename/delete codepath.  ...and then it had to be copied
for modify/delete, and for rename/rename(1to2) conflicts, ...and yet it
still missed some.  Further, when it was discovered that there were also
file/submodule conflicts and submodule/directory conflicts, we needed to
copy the special submodule handling code to all the special cases
throughout the codebase.

And then it was discovered that our handling of directory/file conflicts
was suboptimal because it would create untracked files to store the
contents of the conflicting file, which would not be cleaned up if
someone were to run a 'git merge --abort' or 'git rebase --abort'.  It
was also difficult or scary to try to add or remove the index entries
corresponding to these files given the directory/file conflict in the
index.  But changing merge-recursive.c to handle these correctly was a
royal pain because there were so many sites in the code with similar but
not identical code for handling directory/file/submodule conflicts that
would all need to be updated.

I have worked hard to push all directory/file/submodule conflict
handling in merge-ort through a single codepath, and avoid creating
untracked files for storing tracked content (it does record things at
alternate paths, but makes sure they have higher-order stages in the
index).

Since updating merge-recursive is too much work and we don't want to
destabilize it, instead update the testsuite to have different
expectations for relevant directory/file/submodule conflict tests.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 81 insertions, 27 deletions

diff --git a/t/t6402-merge-rename.sh b/t/t6402-merge-rename.sh
index bbbba3d..47d4434 100755
--- a/t/t6402-merge-rename.sh
+++ b/t/t6402-merge-rename.sh
@@ -397,7 +397,12 @@ test_expect_success 'Rename+D/F conflict; renamed file cannot merge and dir in t
 	test_must_fail git merge --strategy=recursive dir-in-way &&
 
 	test 5 -eq "$(git ls-files -u | wc -l)" &&
-	test 3 -eq "$(git ls-files -u dir | grep -v file-in-the-way | wc -l)" &&
+	if test "$GIT_TEST_MERGE_ALGORITHM" = ort
+	then
+		test 3 -eq "$(git ls-files -u dir~HEAD | wc -l)"
+	else
+		test 3 -eq "$(git ls-files -u dir | grep -v file-in-the-way | wc -l)"
+	fi &&
 	test 2 -eq "$(git ls-files -u dir/file-in-the-way | wc -l)" &&
 
 	test_must_fail git diff --quiet &&
@@ -415,7 +420,12 @@ test_expect_success 'Same as previous, but merged other way' '
 	test_must_fail git merge --strategy=recursive renamed-file-has-conflicts &&
 
 	test 5 -eq "$(git ls-files -u | wc -l)" &&
-	test 3 -eq "$(git ls-files -u dir | grep -v file-in-the-way | wc -l)" &&
+	if test "$GIT_TEST_MERGE_ALGORITHM" = ort
+	then
+		test 3 -eq "$(git ls-files -u dir~renamed-file-has-conflicts | wc -l)"
+	else
+		test 3 -eq "$(git ls-files -u dir | grep -v file-in-the-way | wc -l)"
+	fi &&
 	test 2 -eq "$(git ls-files -u dir/file-in-the-way | wc -l)" &&
 
 	test_must_fail git diff --quiet &&
@@ -471,7 +481,12 @@ test_expect_success 'both rename source and destination involved in D/F conflict
 	git checkout -q rename-dest^0 &&
 	test_must_fail git merge --strategy=recursive source-conflict &&
 
-	test 1 -eq "$(git ls-files -u | wc -l)" &&
+	if test "$GIT_TEST_MERGE_ALGORITHM" = ort
+	then
+		test 2 -eq "$(git ls-files -u | wc -l)"
+	else
+		test 1 -eq "$(git ls-files -u | wc -l)"
+	fi &&
 
 	test_must_fail git diff --quiet &&
 
@@ -505,34 +520,63 @@ test_expect_success 'setup pair rename to parent of other (D/F conflicts)' '
 	git commit -m "Rename one/file -> two"
 '
 
-test_expect_success 'pair rename to parent of other (D/F conflicts) w/ untracked dir' '
-	git checkout -q rename-one^0 &&
-	mkdir one &&
-	test_must_fail git merge --strategy=recursive rename-two &&
+if test "$GIT_TEST_MERGE_ALGORITHM" = ort
+then
+	test_expect_success 'pair rename to parent of other (D/F conflicts) w/ untracked dir' '
+		git checkout -q rename-one^0 &&
+		mkdir one &&
+		test_must_fail git merge --strategy=recursive rename-two &&
 
-	test 2 -eq "$(git ls-files -u | wc -l)" &&
-	test 1 -eq "$(git ls-files -u one | wc -l)" &&
-	test 1 -eq "$(git ls-files -u two | wc -l)" &&
+		test 4 -eq "$(git ls-files -u | wc -l)" &&
+		test 2 -eq "$(git ls-files -u one | wc -l)" &&
+		test 2 -eq "$(git ls-files -u two | wc -l)" &&
 
-	test_must_fail git diff --quiet &&
+		test_must_fail git diff --quiet &&
 
-	test 4 -eq $(find . | grep -v .git | wc -l) &&
+		test 3 -eq $(find . | grep -v .git | wc -l) &&
 
-	test_path_is_dir one &&
-	test_path_is_file one~rename-two &&
-	test_path_is_file two &&
-	test "other" = $(cat one~rename-two) &&
-	test "stuff" = $(cat two)
-'
+		test_path_is_file one &&
+		test_path_is_file two &&
+		test "other" = $(cat one) &&
+		test "stuff" = $(cat two)
+	'
+else
+	test_expect_success 'pair rename to parent of other (D/F conflicts) w/ untracked dir' '
+		git checkout -q rename-one^0 &&
+		mkdir one &&
+		test_must_fail git merge --strategy=recursive rename-two &&
+
+		test 2 -eq "$(git ls-files -u | wc -l)" &&
+		test 1 -eq "$(git ls-files -u one | wc -l)" &&
+		test 1 -eq "$(git ls-files -u two | wc -l)" &&
+
+		test_must_fail git diff --quiet &&
+
+		test 4 -eq $(find . | grep -v .git | wc -l) &&
+
+		test_path_is_dir one &&
+		test_path_is_file one~rename-two &&
+		test_path_is_file two &&
+		test "other" = $(cat one~rename-two) &&
+		test "stuff" = $(cat two)
+	'
+fi
 
 test_expect_success 'pair rename to parent of other (D/F conflicts) w/ clean start' '
 	git reset --hard &&
 	git clean -fdqx &&
 	test_must_fail git merge --strategy=recursive rename-two &&
 
-	test 2 -eq "$(git ls-files -u | wc -l)" &&
-	test 1 -eq "$(git ls-files -u one | wc -l)" &&
-	test 1 -eq "$(git ls-files -u two | wc -l)" &&
+	if test "$GIT_TEST_MERGE_ALGORITHM" = ort
+	then
+		test 4 -eq "$(git ls-files -u | wc -l)" &&
+		test 2 -eq "$(git ls-files -u one | wc -l)" &&
+		test 2 -eq "$(git ls-files -u two | wc -l)"
+	else
+		test 2 -eq "$(git ls-files -u | wc -l)" &&
+		test 1 -eq "$(git ls-files -u one | wc -l)" &&
+		test 1 -eq "$(git ls-files -u two | wc -l)"
+	fi &&
 
 	test_must_fail git diff --quiet &&
 
@@ -572,12 +616,22 @@ test_expect_success 'check handling of differently renamed file with D/F conflic
 	git checkout -q first-rename^0 &&
 	test_must_fail git merge --strategy=recursive second-rename &&
 
-	test 5 -eq "$(git ls-files -s | wc -l)" &&
-	test 3 -eq "$(git ls-files -u | wc -l)" &&
-	test 1 -eq "$(git ls-files -u one | wc -l)" &&
-	test 1 -eq "$(git ls-files -u two | wc -l)" &&
-	test 1 -eq "$(git ls-files -u original | wc -l)" &&
-	test 2 -eq "$(git ls-files -o | wc -l)" &&
+	if test "$GIT_TEST_MERGE_ALGORITHM" = ort
+	then
+		test 5 -eq "$(git ls-files -s | wc -l)" &&
+		test 3 -eq "$(git ls-files -u | wc -l)" &&
+		test 1 -eq "$(git ls-files -u one~HEAD | wc -l)" &&
+		test 1 -eq "$(git ls-files -u two~second-rename | wc -l)" &&
+		test 1 -eq "$(git ls-files -u original | wc -l)" &&
+		test 0 -eq "$(git ls-files -o | wc -l)"
+	else
+		test 5 -eq "$(git ls-files -s | wc -l)" &&
+		test 3 -eq "$(git ls-files -u | wc -l)" &&
+		test 1 -eq "$(git ls-files -u one | wc -l)" &&
+		test 1 -eq "$(git ls-files -u two | wc -l)" &&
+		test 1 -eq "$(git ls-files -u original | wc -l)" &&
+		test 2 -eq "$(git ls-files -o | wc -l)"
+	fi &&
 
 	test_path_is_file one/file &&
 	test_path_is_file two/file &&