Rework checkout with new strategy options

This is a major reworking of checkout strategy options.  The
checkout code is now sensitive to the contents of the HEAD tree
and the new options allow you to update the working tree so that
it will match the index content only when it previously matched
the contents of the HEAD.  This allows you to, for example, to
distinguish between removing files that are in the HEAD but not
in the index, vs just removing all untracked files.

Because of various corner cases that arise, etc., this required
some additional capabilities in rmdir and other utility functions.

This includes the beginnings of an implementation of code to read
a partial tree into the index based on a pathspec, but that is
not enabled because of the possibility of creating conflicting
index entries.

1 files changed, 46 insertions, 28 deletions

diff --git a/tests-clar/checkout/index.c b/tests-clar/checkout/index.c
index 18c59a45d..72044d01c 100644
--- a/tests-clar/checkout/index.c
+++ b/tests-clar/checkout/index.c
@@ -26,7 +26,7 @@ void test_checkout_index__initialize(void)
 	git_tree *tree;
 
 	memset(&g_opts, 0, sizeof(g_opts));
-	g_opts.checkout_strategy = GIT_CHECKOUT_CREATE_MISSING;
+	g_opts.checkout_strategy = GIT_CHECKOUT_SAFE;
 
 	g_repo = cl_git_sandbox_init("testrepo");
 
@@ -78,7 +78,6 @@ void test_checkout_index__can_create_missing_files(void)
 	cl_assert_equal_i(false, git_path_isfile("./testrepo/branch_file.txt"));
 	cl_assert_equal_i(false, git_path_isfile("./testrepo/new.txt"));
 
-	g_opts.checkout_strategy = GIT_CHECKOUT_CREATE_MISSING;
 	cl_git_pass(git_checkout_index(g_repo, &g_opts));
 
 	test_file_contents("./testrepo/README", "hey there\n");
@@ -94,7 +93,7 @@ void test_checkout_index__can_remove_untracked_files(void)
 
 	cl_assert_equal_i(true, git_path_isdir("./testrepo/dir/subdir/subsubdir"));
 
-	g_opts.checkout_strategy = GIT_CHECKOUT_REMOVE_UNTRACKED;
+	g_opts.checkout_strategy |= GIT_CHECKOUT_REMOVE_UNTRACKED;
 	cl_git_pass(git_checkout_index(g_repo, &g_opts));
 
 	cl_assert_equal_i(false, git_path_isdir("./testrepo/dir"));
@@ -203,7 +202,11 @@ void test_checkout_index__donot_overwrite_modified_file_by_default(void)
 {
 	cl_git_mkfile("./testrepo/new.txt", "This isn't what's stored!");
 
-	g_opts.checkout_strategy = 0;
+	/* set this up to not return an error code on conflicts, but it
+	 * still will not have permission to overwrite anything...
+	 */
+	g_opts.checkout_strategy = GIT_CHECKOUT_ALLOW_CONFLICTS;
+
 	cl_git_pass(git_checkout_index(g_repo, &g_opts));
 
 	test_file_contents("./testrepo/new.txt", "This isn't what's stored!");
@@ -213,7 +216,8 @@ void test_checkout_index__can_overwrite_modified_file(void)
 {
 	cl_git_mkfile("./testrepo/new.txt", "This isn't what's stored!");
 
-	g_opts.checkout_strategy = GIT_CHECKOUT_OVERWRITE_MODIFIED;
+	g_opts.checkout_strategy |= GIT_CHECKOUT_UPDATE_MODIFIED;
+
 	cl_git_pass(git_checkout_index(g_repo, &g_opts));
 
 	test_file_contents("./testrepo/new.txt", "my new file\n");
@@ -282,28 +286,30 @@ void test_checkout_index__options_open_flags(void)
 
 	g_opts.file_open_flags = O_CREAT | O_RDWR | O_APPEND;
 
-	g_opts.checkout_strategy |= GIT_CHECKOUT_OVERWRITE_MODIFIED;
+	g_opts.checkout_strategy |= GIT_CHECKOUT_UPDATE_MODIFIED;
 	cl_git_pass(git_checkout_index(g_repo, &g_opts));
 
 	test_file_contents("./testrepo/new.txt", "hi\nmy new file\n");
 }
 
-struct notify_data {
+struct conflict_data {
 	const char *file;
 	const char *sha;
 };
 
-static int notify_cb(
-	const char *skipped_file,
+static int conflict_cb(
+	const char *conflict_file,
 	const git_oid *blob_oid,
-	int file_mode,
+	unsigned int index_mode,
+	unsigned int wd_mode,
 	void *payload)
 {
-	struct notify_data *expectations = (struct notify_data *)payload;
+	struct conflict_data *expectations = (struct conflict_data *)payload;
 
-	GIT_UNUSED(file_mode);
+	GIT_UNUSED(index_mode);
+	GIT_UNUSED(wd_mode);
 
-	cl_assert_equal_s(expectations->file, skipped_file);
+	cl_assert_equal_s(expectations->file, conflict_file);
 	cl_assert_equal_i(0, git_oid_streq(blob_oid, expectations->sha));
 
 	return 0;
@@ -311,7 +317,7 @@ static int notify_cb(
 
 void test_checkout_index__can_notify_of_skipped_files(void)
 {
-	struct notify_data data;
+	struct conflict_data data;
 
 	cl_git_mkfile("./testrepo/new.txt", "This isn't what's stored!");
 
@@ -324,22 +330,24 @@ void test_checkout_index__can_notify_of_skipped_files(void)
 	data.file = "new.txt";
 	data.sha = "a71586c1dfe8a71c6cbf6c129f404c5642ff31bd";
 
-	g_opts.checkout_strategy = GIT_CHECKOUT_CREATE_MISSING;
-	g_opts.skipped_notify_cb = notify_cb;
-	g_opts.notify_payload = &data;
+	g_opts.checkout_strategy |= GIT_CHECKOUT_ALLOW_CONFLICTS;
+	g_opts.conflict_cb = conflict_cb;
+	g_opts.conflict_payload = &data;
 
 	cl_git_pass(git_checkout_index(g_repo, &g_opts));
 }
 
-static int dont_notify_cb(
-	const char *skipped_file,
+static int dont_conflict_cb(
+	const char *conflict_file,
 	const git_oid *blob_oid,
-	int file_mode,
+	unsigned int index_mode,
+	unsigned int wd_mode,
 	void *payload)
 {
-	GIT_UNUSED(skipped_file);
+	GIT_UNUSED(conflict_file);
 	GIT_UNUSED(blob_oid);
-	GIT_UNUSED(file_mode);
+	GIT_UNUSED(index_mode);
+	GIT_UNUSED(wd_mode);
 	GIT_UNUSED(payload);
 
 	cl_assert(false);
@@ -354,9 +362,9 @@ void test_checkout_index__wont_notify_of_expected_line_ending_changes(void)
 
 	cl_git_mkfile("./testrepo/new.txt", "my new file\r\n");
 
-	g_opts.checkout_strategy = GIT_CHECKOUT_CREATE_MISSING;
-	g_opts.skipped_notify_cb = dont_notify_cb;
-	g_opts.notify_payload = NULL;
+	g_opts.checkout_strategy |= GIT_CHECKOUT_ALLOW_CONFLICTS;
+	g_opts.conflict_cb = dont_conflict_cb;
+	g_opts.conflict_payload = NULL;
 
 	cl_git_pass(git_checkout_index(g_repo, &g_opts));
 }
@@ -389,8 +397,9 @@ void test_checkout_index__can_overcome_name_clashes(void)
 	cl_git_pass(p_mkdir("./testrepo/path1", 0777));
 	cl_git_mkfile("./testrepo/path1/file1", "content\r\n");
 
-	cl_git_pass(git_index_add(index, "path0", 0));
-	cl_git_pass(git_index_add(index, "path1/file1", 0));
+	cl_git_pass(git_index_add_from_workdir(index, "path0"));
+	cl_git_pass(git_index_add_from_workdir(index, "path1/file1"));
+
 
 	cl_git_pass(p_unlink("./testrepo/path0"));
 	cl_git_pass(git_futils_rmdir_r(
@@ -400,11 +409,20 @@ void test_checkout_index__can_overcome_name_clashes(void)
 	cl_git_pass(p_mkdir("./testrepo/path0", 0777));
 	cl_git_mkfile("./testrepo/path0/file0", "content\r\n");
 
-	g_opts.checkout_strategy = GIT_CHECKOUT_CREATE_MISSING;
+	cl_assert(git_path_isfile("./testrepo/path1"));
+	cl_assert(git_path_isfile("./testrepo/path0/file0"));
+
+	g_opts.checkout_strategy = GIT_CHECKOUT_SAFE | GIT_CHECKOUT_ALLOW_CONFLICTS;
 	cl_git_pass(git_checkout_index(g_repo, &g_opts));
 
 	cl_assert(git_path_isfile("./testrepo/path1"));
 	cl_assert(git_path_isfile("./testrepo/path0/file0"));
 
+	g_opts.checkout_strategy = GIT_CHECKOUT_FORCE;
+	cl_git_pass(git_checkout_index(g_repo, &g_opts));
+
+	cl_assert(git_path_isfile("./testrepo/path0"));
+	cl_assert(git_path_isfile("./testrepo/path1/file1"));
+
 	git_index_free(index);
 }