[v6,5/6] worktree: copy sparse-checkout patterns and config on add

Commit Message

Derrick Stolee Feb. 7, 2022, 9:33 p.m. UTC

From: Derrick Stolee <[e-mail]>

When adding a new worktree, it is reasonable to expect that we want to
use the current set of sparse-checkout settings for that new worktree.
This is particularly important for repositories where the worktree would
become too large to be useful. This is even more important when using
partial clone as well, since we want to avoid downloading the missing
blobs for files that should not be written to the new worktree.

The only way to create such a worktree without this intermediate step of
expanding the full worktree is to copy the sparse-checkout patterns and
config settings during 'git worktree add'. Each worktree has its own
sparse-checkout patterns, and the default behavior when the
sparse-checkout file is missing is to include all paths at HEAD. Thus,
we need to have patterns from somewhere, they might as well be the
current worktree's patterns. These are then modified independently in
the future.

In addition to the sparse-checkout file, copy the worktree config file
if worktree config is enabled and the file exists. This will copy over
any important settings to ensure the new worktree behaves the same as
the current one. The only exception we must continue to make is that
core.bare and core.worktree should become unset in the worktree's config
file.

Signed-off-by: Derrick Stolee <[e-mail]>
---
 builtin/worktree.c                 | 63 ++++++++++++++++++++++++++++++
 t/t1091-sparse-checkout-builtin.sh | 31 +++++++++++----
 t/t2400-worktree-add.sh            | 58 ++++++++++++++++++++++++++-
 3 files changed, 142 insertions(+), 10 deletions(-)

Comments

Eric Sunshine Feb. 15, 2022, 10:23 p.m. UTC | #1

On Mon, Feb 7, 2022 at 4:33 PM Derrick Stolee via GitGitGadget
<[e-mail]> wrote:
> When adding a new worktree, it is reasonable to expect that we want to
> use the current set of sparse-checkout settings for that new worktree.
> This is particularly important for repositories where the worktree would
> become too large to be useful. This is even more important when using
> partial clone as well, since we want to avoid downloading the missing
> blobs for files that should not be written to the new worktree.
> [...]
> Signed-off-by: Derrick Stolee <[e-mail]>
> ---
> diff --git a/builtin/worktree.c b/builtin/worktree.c
> @@ -335,6 +335,69 @@ static int add_worktree(const char *path, const char *refname,
> +       /*
> +        * If the current worktree has sparse-checkout enabled, then copy
> +        * the sparse-checkout patterns from the current worktree.
> +        */
> +       if (core_apply_sparse_checkout) {
> +               char *from_file = git_pathdup("info/sparse-checkout");
> +               char *to_file = xstrfmt("%s/info/sparse-checkout",
> +                                       sb_repo.buf);
> +
> +               if (file_exists(from_file)) {
> +                       if (safe_create_leading_directories(to_file) ||
> +                           copy_file(to_file, from_file, 0666))
> +                               error(_("failed to copy '%s' to '%s'; sparse-checkout may not work correctly"),
> +                                     from_file, to_file);
> +               }
> +
> +               free(from_file);
> +               free(to_file);
> +       }
> +
> +       /*
> +        * If we are using worktree config, then copy all current config
> +        * values from the current worktree into the new one, that way the
> +        * new worktree behaves the same as this one.
> +        */
> +       if (repository_format_worktree_config) {
> +               char *from_file = git_pathdup("config.worktree");
> +               char *to_file = xstrfmt("%s/config.worktree",
> +                                       sb_repo.buf);
> +
> +               if (file_exists(from_file)) {
> +                       struct config_set cs = { { 0 } };
> +                       const char *core_worktree;
> +                       int bare;
> +
> +                       if (safe_create_leading_directories(to_file) ||
> +                           copy_file(to_file, from_file, 0666)) {
> +                               error(_("failed to copy worktree config from '%s' to '%s'"),
> +                                     from_file, to_file);
> +                               goto worktree_copy_cleanup;
> +                       }
> +
> +                       git_configset_init(&cs);
> +                       git_configset_add_file(&cs, from_file);
> +
> +                       if (!git_configset_get_bool(&cs, "core.bare", &bare) &&
> +                           bare &&
> +                           git_config_set_multivar_in_file_gently(
> +                                       to_file, "core.bare", NULL, "true", 0))
> +                               error(_("failed to unset 'core.bare' in '%s'"), to_file);
> +                       if (!git_configset_get_value(&cs, "core.worktree", &core_worktree) &&
> +                           git_config_set_in_file_gently(to_file,
> +                                                         "core.worktree", NULL))
> +                               error(_("failed to unset 'core.worktree' in '%s'"), to_file);
> +
> +                       git_configset_clear(&cs);
> +               }
> +
> +worktree_copy_cleanup:
> +               free(from_file);
> +               free(to_file);
> +       }

Given that add_worktree() is already overly long, a good future
cleanup would be to move these two new hunks of functionality into
separate functions -- copy_sparsity() and copy_config(), perhaps -- in
builtin/worktree.c. This should be simple enough since (I think) the
only state that needs to be passed to them is `sb_repo`. But such
cleanup needn't hold up this series.

Patch

diff --git a/builtin/worktree.c b/builtin/worktree.c
index 2838254f7f2..c6eb636329a 100644
--- a/builtin/worktree.c
+++ b/builtin/worktree.c
@@ -335,6 +335,69 @@  static int add_worktree(const char *path, const char *refname,
 	strbuf_addf(&sb, "%s/commondir", sb_repo.buf);
 	write_file(sb.buf, "../..");
 
+	/*
+	 * If the current worktree has sparse-checkout enabled, then copy
+	 * the sparse-checkout patterns from the current worktree.
+	 */
+	if (core_apply_sparse_checkout) {
+		char *from_file = git_pathdup("info/sparse-checkout");
+		char *to_file = xstrfmt("%s/info/sparse-checkout",
+					sb_repo.buf);
+
+		if (file_exists(from_file)) {
+			if (safe_create_leading_directories(to_file) ||
+			    copy_file(to_file, from_file, 0666))
+				error(_("failed to copy '%s' to '%s'; sparse-checkout may not work correctly"),
+				      from_file, to_file);
+		}
+
+		free(from_file);
+		free(to_file);
+	}
+
+	/*
+	 * If we are using worktree config, then copy all current config
+	 * values from the current worktree into the new one, that way the
+	 * new worktree behaves the same as this one.
+	 */
+	if (repository_format_worktree_config) {
+		char *from_file = git_pathdup("config.worktree");
+		char *to_file = xstrfmt("%s/config.worktree",
+					sb_repo.buf);
+
+		if (file_exists(from_file)) {
+			struct config_set cs = { { 0 } };
+			const char *core_worktree;
+			int bare;
+
+			if (safe_create_leading_directories(to_file) ||
+			    copy_file(to_file, from_file, 0666)) {
+				error(_("failed to copy worktree config from '%s' to '%s'"),
+				      from_file, to_file);
+				goto worktree_copy_cleanup;
+			}
+
+			git_configset_init(&cs);
+			git_configset_add_file(&cs, from_file);
+
+			if (!git_configset_get_bool(&cs, "core.bare", &bare) &&
+			    bare &&
+			    git_config_set_multivar_in_file_gently(
+					to_file, "core.bare", NULL, "true", 0))
+				error(_("failed to unset 'core.bare' in '%s'"), to_file);
+			if (!git_configset_get_value(&cs, "core.worktree", &core_worktree) &&
+			    git_config_set_in_file_gently(to_file,
+							  "core.worktree", NULL))
+				error(_("failed to unset 'core.worktree' in '%s'"), to_file);
+
+			git_configset_clear(&cs);
+		}
+
+worktree_copy_cleanup:
+		free(from_file);
+		free(to_file);
+	}
+
 	strvec_pushf(&child_env, "%s=%s", GIT_DIR_ENVIRONMENT, sb_git.buf);
 	strvec_pushf(&child_env, "%s=%s", GIT_WORK_TREE_ENVIRONMENT, path);
 	cp.git_cmd = 1;
diff --git a/t/t1091-sparse-checkout-builtin.sh b/t/t1091-sparse-checkout-builtin.sh
index be6ea4ffe33..8a757b43e6c 100755
--- a/t/t1091-sparse-checkout-builtin.sh
+++ b/t/t1091-sparse-checkout-builtin.sh
@@ -146,9 +146,9 @@  test_expect_success 'interaction with clone --no-checkout (unborn index)' '
 '
 
 test_expect_success 'set enables config' '
-	git init empty-config &&
+	git init worktree-config &&
 	(
-		cd empty-config &&
+		cd worktree-config &&
 		test_commit test file &&
 		test_path_is_missing .git/config.worktree &&
 		git sparse-checkout set nothing &&
@@ -201,6 +201,21 @@  test_expect_success 'add to sparse-checkout' '
 	check_files repo "a folder1 folder2"
 '
 
+test_expect_success 'worktree: add copies sparse-checkout patterns' '
+	cat repo/.git/info/sparse-checkout >old &&
+	test_when_finished cp old repo/.git/info/sparse-checkout &&
+	test_when_finished git -C repo worktree remove ../worktree &&
+	git -C repo sparse-checkout set --no-cone "/*" &&
+	git -C repo worktree add --quiet ../worktree 2>err &&
+	test_must_be_empty err &&
+	new="$(git -C worktree rev-parse --git-path info/sparse-checkout)" &&
+	test_path_is_file "$new" &&
+	test_cmp repo/.git/info/sparse-checkout "$new" &&
+	git -C worktree sparse-checkout set --cone &&
+	test_cmp_config -C worktree true core.sparseCheckoutCone &&
+	test_must_fail git -C repo core.sparseCheckoutCone
+'
+
 test_expect_success 'cone mode: match patterns' '
 	git -C repo config --worktree core.sparseCheckoutCone true &&
 	rm -rf repo/a repo/folder1 repo/folder2 &&
@@ -520,13 +535,13 @@  test_expect_success 'interaction with submodules' '
 '
 
 test_expect_success 'different sparse-checkouts with worktrees' '
+	git -C repo sparse-checkout set --cone deep folder1 &&
 	git -C repo worktree add --detach ../worktree &&
-	check_files worktree "a deep folder1 folder2" &&
-	git -C worktree sparse-checkout init --cone &&
-	git -C repo sparse-checkout set folder1 &&
-	git -C worktree sparse-checkout set deep/deeper1 &&
-	check_files repo a folder1 &&
-	check_files worktree a deep
+	check_files worktree "a deep folder1" &&
+	git -C repo sparse-checkout set --cone folder1 &&
+	git -C worktree sparse-checkout set --cone deep/deeper1 &&
+	check_files repo "a folder1" &&
+	check_files worktree "a deep"
 '
 
 test_expect_success 'set using filename keeps file on-disk' '
diff --git a/t/t2400-worktree-add.sh b/t/t2400-worktree-add.sh
index 37ad79470fb..43139af08fc 100755
--- a/t/t2400-worktree-add.sh
+++ b/t/t2400-worktree-add.sh
@@ -165,8 +165,62 @@  test_expect_success '"add" default branch of a bare repo' '
 	(
 		git clone --bare . bare2 &&
 		cd bare2 &&
-		git worktree add ../there3 main
-	)
+		git worktree add ../there3 main &&
+		cd ../there3 &&
+		# Simple check that a Git command does not
+		# immediately fail with the current setup
+		git status
+	) &&
+	cat >expect <<-EOF &&
+	init.t
+	EOF
+	ls there3 >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success '"add" to bare repo with worktree config' '
+	(
+		git clone --bare . bare3 &&
+		cd bare3 &&
+		git config extensions.worktreeconfig true &&
+
+		# Add config values that are erroneous to have in
+		# a config.worktree file outside of the main
+		# working tree, to check that Git filters them out
+		# when copying config during "git worktree add".
+		git config --worktree core.bare true &&
+		git config --worktree core.worktree "$(pwd)" &&
+
+		# We want to check that bogus.key is copied
+		git config --worktree bogus.key value &&
+		git config --unset core.bare &&
+		git worktree add ../there4 main &&
+		cd ../there4 &&
+
+		# Simple check that a Git command does not
+		# immediately fail with the current setup
+		git status &&
+		git worktree add --detach ../there5 &&
+		cd ../there5 &&
+		git status
+	) &&
+
+	# the worktree has the arbitrary value copied.
+	test_cmp_config -C there4 value bogus.key &&
+	test_cmp_config -C there5 value bogus.key &&
+
+	# however, core.bare and core.worktree were removed.
+	test_must_fail git -C there4 config core.bare &&
+	test_must_fail git -C there4 config core.worktree &&
+
+	cat >expect <<-EOF &&
+	init.t
+	EOF
+
+	ls there4 >actual &&
+	test_cmp expect actual &&
+	ls there5 >actual &&
+	test_cmp expect actual
 '
 
 test_expect_success 'checkout with grafts' '