[PATCH v6] write-tree: optimize sparse integration

[Shuqi Liang <cheskaqiqi@gmail.com>]

* 'on all' in the title of the test 'write-tree on all' was unclear;
remove it.

* Add a baseline 'test_all_match git write-tree' before making any
changes to the index, providing a reference point for the 'write-tree'
prior to any modifications.

* Add a comparison of the output of 'git status --porcelain=v2' to test
the working tree after 'write-tree' exits.

* Ensure SKIP_WORKTREE files weren't materialized on disk by using
"test_path_is_missing".

Signed-off-by: Shuqi Liang <cheskaqiqi@gmail.com>
---

My apologies, please ignore the previous v6 iteration.

change sine V5:

* We not need to check for the presence of a repository before calling
'prepare_repo_settings()', as the control flow should not reach this
point without a repository. This is because 'setup_git_directory()' is
called for commands with RUN_SETUP set, except when the command line
argument is "-h", in which case 'parse_options()' takes over and exits
the program.

* Change the commit message to make it easier to read.

* Remove whitespace before the line that says # check that SKIP_WORKTREE
files are not materialized".

Range-diff against v5:
1:  df470c2d61 ! 1:  e6c21ec6b8 write-tree: optimize sparse integration
    @@ Metadata
      ## Commit message ##
         write-tree: optimize sparse integration
     
    -    'prepare_repo_settings()' needs to be run inside a repository. Ensure
    -    that the code checks for the presence of a repository before calling
    -    this function. 'write-tree on all' had an unclear meaning of 'on all'.
    -    Change the test name to simply 'write-tree'. Add a baseline
    -    'test_all_match git write-tree' before making any changes to the index,
    -    providing a reference point for the 'write-tree' prior to any
    -    modifications. Add a comparison of the output of
    -    'git status --porcelain=v2' to test the working tree after 'write-tree'
    -    exits. Ensure SKIP_WORKTREE files weren't materialized on disk by using
    +    * 'on all' in the title of the test 'write-tree on all' was unclear;
    +    remove it.
    +
    +    * Add a baseline 'test_all_match git write-tree' before making any
    +    changes to the index, providing a reference point for the 'write-tree'
    +    prior to any modifications.
    +
    +    * Add a comparison of the output of 'git status --porcelain=v2' to test
    +    the working tree after 'write-tree' exits.
    +
    +    * Ensure SKIP_WORKTREE files weren't materialized on disk by using
         "test_path_is_missing".
     
         Signed-off-by: Shuqi Liang <cheskaqiqi@gmail.com>
     
    - ## builtin/write-tree.c ##
    -@@ builtin/write-tree.c: int cmd_write_tree(int argc, const char **argv, const char *cmd_prefix)
    - 	argc = parse_options(argc, argv, cmd_prefix, write_tree_options,
    - 			     write_tree_usage, 0);
    - 
    --	prepare_repo_settings(the_repository);
    --	the_repository->settings.command_requires_full_index = 0;
    -+	if (the_repository->gitdir) {
    -+		prepare_repo_settings(the_repository);
    -+		the_repository->settings.command_requires_full_index = 0;
    -+	}
    - 
    - 	ret = write_index_as_tree(&oid, &the_index, get_index_file(), flags,
    - 				  tree_prefix);
    -
      ## t/t1092-sparse-checkout-compatibility.sh ##
     @@ t/t1092-sparse-checkout-compatibility.sh: test_expect_success 'grep sparse directory within submodules' '
      	test_cmp actual expect
    @@ t/t1092-sparse-checkout-compatibility.sh: test_expect_success 'grep sparse direc
     +	test_all_match git update-index folder1/a &&
     +	test_all_match git write-tree &&
     +	test_all_match git status --porcelain=v2 &&
    -+	
    ++
     +	# check that SKIP_WORKTREE files are not materialized
     +	test_path_is_missing sparse-checkout/folder2/a &&
     +	test_path_is_missing sparse-index/folder2/a
-- 


 t/t1092-sparse-checkout-compatibility.sh | 18 ++++++++++++++----
 1 file changed, 14 insertions(+), 4 deletions(-)

diff --git a/t/t1092-sparse-checkout-compatibility.sh b/t/t1092-sparse-checkout-compatibility.sh
index 0c784813f1..3aa6356a85 100755
--- a/t/t1092-sparse-checkout-compatibility.sh
+++ b/t/t1092-sparse-checkout-compatibility.sh
@@ -2080,22 +2080,32 @@ test_expect_success 'grep sparse directory within submodules' '
 	test_cmp actual expect
 '
 
-test_expect_success 'write-tree on all' '
+test_expect_success 'write-tree' '
 	init_repos &&
 
+	test_all_match git write-tree &&
+
 	write_script edit-contents <<-\EOF &&
 	echo text >>"$1"
 	EOF
 
+	# make a change inside the sparse cone
 	run_on_all ../edit-contents deep/a &&
-	run_on_all git update-index deep/a &&
+	test_all_match git update-index deep/a &&
 	test_all_match git write-tree &&
+	test_all_match git status --porcelain=v2 &&
 
+	# make a change outside the sparse cone
 	run_on_all mkdir -p folder1 &&
 	run_on_all cp a folder1/a &&
 	run_on_all ../edit-contents folder1/a &&
-	run_on_all git update-index folder1/a &&
-	test_all_match git write-tree
+	test_all_match git update-index folder1/a &&
+	test_all_match git write-tree &&
+	test_all_match git status --porcelain=v2 &&
+
+	# check that SKIP_WORKTREE files are not materialized
+	test_path_is_missing sparse-checkout/folder2/a &&
+	test_path_is_missing sparse-index/folder2/a
 '
 
 test_expect_success 'sparse-index is not expanded: write-tree' '
-- 
2.39.0