diff mbox series

[v3,1/8] scalar: constrain enlistment search

Message ID 2f6cad8361324cecdb0ee7b13a96477a8317c358.1660858853.git.gitgitgadget@gmail.com (mailing list archive)
State Accepted
Commit 65f6a9eb0b9b38ca10b4e6a2b02671036981195f
Headers show
Series [v3,1/8] scalar: constrain enlistment search | expand

Commit Message

Victoria Dye Aug. 18, 2022, 9:40 p.m. UTC
From: Victoria Dye <vdye@github.com>

Make the search for repository and enlistment root in
'setup_enlistment_directory()' more constrained to simplify behavior and
adhere to 'GIT_CEILING_DIRECTORIES'.

Previously, 'setup_enlistment_directory()' would check whether the provided
path (or current working directory) '<dir>' or its subdirectory '<dir>/src'
was a repository root. If not, the process would repeat on the parent of
'<dir>' until the repository was found or it reached the root of the
filesystem. This meant that a user could specify a path *anywhere* inside an
enlistment (including paths not in the repository contained within the
enlistment) and it would be found.

The downside to this process is that the search would not account for
'GIT_CEILING_DIRECTORIES', so the upward search could result in modifying
repository contents past 'GIT_CEILING_DIRECTORIES'. Similarly, operations
like 'scalar delete' could end up unintentionally deleting the parent of a
repo if its root was named 'src'.

To make this 'setup_enlistment_directory()' both adhere to
'GIT_CEILING_DIRECTORIES' and avoid unwanted deletions, the search for an
enlistment directory is simplified to:

- if '<dir>/src' is a repository root, '<dir>' is the enlistment root
- if '<dir>' is either the repository root or contained within a repository,
  the repository root is the enlistment root

Now, only 'setup_git_directory()' (called by 'setup_enlistment_directory()')
searches upwards from the 'scalar' specified path, enforcing
'GIT_CEILING_DIRECTORIES' in the process. Additionally, 'scalar delete
<dir>/src' will not delete '<dir>' (if users would like to delete it, they
can still specify the enlistment root with 'scalar delete <dir>'). This is
true of any 'scalar' operation; users can invoke 'scalar' on the enlistment
root, but paths must otherwise be inside the repository to be valid.

To help clarify the updated behavior, new tests are added to
't9099-scalar.sh'.

Finally, this change leaves 'strbuf_parent_directory()' with only a single,
WIN32-specific caller in 'delete_enlistment()'. Rather than wrap
'strbuf_parent_directory()' in '#ifdef WIN32' to avoid the "unused function"
compiler error, move the contents of 'strbuf_parent_directory()' into
'delete_enlistment()' and remove the function.

Helped-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Victoria Dye <vdye@github.com>
---
 contrib/scalar/scalar.c          | 82 +++++++++++-------------------
 contrib/scalar/t/t9099-scalar.sh | 85 ++++++++++++++++++++++++++++++++
 2 files changed, 113 insertions(+), 54 deletions(-)

Comments

Derrick Stolee Aug. 19, 2022, 6:32 p.m. UTC | #1
On 8/18/2022 5:40 PM, Victoria Dye via GitGitGadget wrote:
> From: Victoria Dye <vdye@github.com>
> 
> Make the search for repository and enlistment root in
> 'setup_enlistment_directory()' more constrained to simplify behavior and
> adhere to 'GIT_CEILING_DIRECTORIES'.

Thanks for doing this rather substantial rework. The logic makes
sense to me and the tests really help to demonstrate the different
cases.

-Stolee
diff mbox series

Patch

diff --git a/contrib/scalar/scalar.c b/contrib/scalar/scalar.c
index 97e71fe19cd..92b648f3511 100644
--- a/contrib/scalar/scalar.c
+++ b/contrib/scalar/scalar.c
@@ -14,29 +14,14 @@ 
 #include "archive.h"
 #include "object-store.h"
 
-/*
- * Remove the deepest subdirectory in the provided path string. Path must not
- * include a trailing path separator. Returns 1 if parent directory found,
- * otherwise 0.
- */
-static int strbuf_parent_directory(struct strbuf *buf)
-{
-	size_t len = buf->len;
-	size_t offset = offset_1st_component(buf->buf);
-	char *path_sep = find_last_dir_sep(buf->buf + offset);
-	strbuf_setlen(buf, path_sep ? path_sep - buf->buf : offset);
-
-	return buf->len < len;
-}
-
 static void setup_enlistment_directory(int argc, const char **argv,
 				       const char * const *usagestr,
 				       const struct option *options,
 				       struct strbuf *enlistment_root)
 {
 	struct strbuf path = STRBUF_INIT;
-	char *root;
-	int enlistment_found = 0;
+	int enlistment_is_repo_parent = 0;
+	size_t len;
 
 	if (startup_info->have_repository)
 		BUG("gitdir already set up?!?");
@@ -49,51 +34,36 @@  static void setup_enlistment_directory(int argc, const char **argv,
 		strbuf_add_absolute_path(&path, argv[0]);
 		if (!is_directory(path.buf))
 			die(_("'%s' does not exist"), path.buf);
+		if (chdir(path.buf) < 0)
+			die_errno(_("could not switch to '%s'"), path.buf);
 	} else if (strbuf_getcwd(&path) < 0)
 		die(_("need a working directory"));
 
 	strbuf_trim_trailing_dir_sep(&path);
-	do {
-		const size_t len = path.len;
-
-		/* check if currently in enlistment root with src/ workdir */
-		strbuf_addstr(&path, "/src");
-		if (is_nonbare_repository_dir(&path)) {
-			if (enlistment_root)
-				strbuf_add(enlistment_root, path.buf, len);
-
-			enlistment_found = 1;
-			break;
-		}
 
-		/* reset to original path */
-		strbuf_setlen(&path, len);
-
-		/* check if currently in workdir */
-		if (is_nonbare_repository_dir(&path)) {
-			if (enlistment_root) {
-				/*
-				 * If the worktree's directory's name is `src`, the enlistment is the
-				 * parent directory, otherwise it is identical to the worktree.
-				 */
-				root = strip_path_suffix(path.buf, "src");
-				strbuf_addstr(enlistment_root, root ? root : path.buf);
-				free(root);
-			}
+	/* check if currently in enlistment root with src/ workdir */
+	len = path.len;
+	strbuf_addstr(&path, "/src");
+	if (is_nonbare_repository_dir(&path)) {
+		enlistment_is_repo_parent = 1;
+		if (chdir(path.buf) < 0)
+			die_errno(_("could not switch to '%s'"), path.buf);
+	}
+	strbuf_setlen(&path, len);
 
-			enlistment_found = 1;
-			break;
-		}
-	} while (strbuf_parent_directory(&path));
+	setup_git_directory();
 
-	if (!enlistment_found)
-		die(_("could not find enlistment root"));
+	if (!the_repository->worktree)
+		die(_("Scalar enlistments require a worktree"));
 
-	if (chdir(path.buf) < 0)
-		die_errno(_("could not switch to '%s'"), path.buf);
+	if (enlistment_root) {
+		if (enlistment_is_repo_parent)
+			strbuf_addbuf(enlistment_root, &path);
+		else
+			strbuf_addstr(enlistment_root, the_repository->worktree);
+	}
 
 	strbuf_release(&path);
-	setup_git_directory();
 }
 
 static int run_git(const char *arg, ...)
@@ -431,6 +401,8 @@  static int delete_enlistment(struct strbuf *enlistment)
 {
 #ifdef WIN32
 	struct strbuf parent = STRBUF_INIT;
+	size_t offset;
+	char *path_sep;
 #endif
 
 	if (unregister_dir())
@@ -441,8 +413,10 @@  static int delete_enlistment(struct strbuf *enlistment)
 	 * Change the current directory to one outside of the enlistment so
 	 * that we may delete everything underneath it.
 	 */
-	strbuf_addbuf(&parent, enlistment);
-	strbuf_parent_directory(&parent);
+	offset = offset_1st_component(enlistment->buf);
+	path_sep = find_last_dir_sep(enlistment->buf + offset);
+	strbuf_add(&parent, enlistment->buf,
+		   path_sep ? path_sep - enlistment->buf : offset);
 	if (chdir(parent.buf) < 0)
 		die_errno(_("could not switch to '%s'"), parent.buf);
 	strbuf_release(&parent);
diff --git a/contrib/scalar/t/t9099-scalar.sh b/contrib/scalar/t/t9099-scalar.sh
index 10b1172a8aa..c069cffebfe 100755
--- a/contrib/scalar/t/t9099-scalar.sh
+++ b/contrib/scalar/t/t9099-scalar.sh
@@ -17,6 +17,91 @@  test_expect_success 'scalar shows a usage' '
 	test_expect_code 129 scalar -h
 '
 
+test_expect_success 'scalar invoked on enlistment root' '
+	test_when_finished rm -rf test src deeper &&
+
+	for enlistment_root in test src deeper/test
+	do
+		git init ${enlistment_root}/src &&
+
+		# Register
+		scalar register ${enlistment_root} &&
+		scalar list >out &&
+		grep "$(pwd)/${enlistment_root}/src\$" out &&
+
+		# Delete (including enlistment root)
+		scalar delete $enlistment_root &&
+		test_path_is_missing $enlistment_root &&
+		scalar list >out &&
+		! grep "^$(pwd)/${enlistment_root}/src\$" out || return 1
+	done
+'
+
+test_expect_success 'scalar invoked on enlistment src repo' '
+	test_when_finished rm -rf test src deeper &&
+
+	for enlistment_root in test src deeper/test
+	do
+		git init ${enlistment_root}/src &&
+
+		# Register
+		scalar register ${enlistment_root}/src &&
+		scalar list >out &&
+		grep "$(pwd)/${enlistment_root}/src\$" out &&
+
+		# Delete (will not include enlistment root)
+		scalar delete ${enlistment_root}/src &&
+		test_path_is_dir $enlistment_root &&
+		scalar list >out &&
+		! grep "^$(pwd)/${enlistment_root}/src\$" out || return 1
+	done
+'
+
+test_expect_success 'scalar invoked when enlistment root and repo are the same' '
+	test_when_finished rm -rf test src deeper &&
+
+	for enlistment_root in test src deeper/test
+	do
+		git init ${enlistment_root} &&
+
+		# Register
+		scalar register ${enlistment_root} &&
+		scalar list >out &&
+		grep "$(pwd)/${enlistment_root}\$" out &&
+
+		# Delete (will not include enlistment root)
+		scalar delete ${enlistment_root} &&
+		test_path_is_missing $enlistment_root &&
+		scalar list >out &&
+		! grep "^$(pwd)/${enlistment_root}\$" out &&
+
+		# Make sure we did not accidentally delete the trash dir
+		test_path_is_dir "$TRASH_DIRECTORY" || return 1
+	done
+'
+
+test_expect_success 'scalar repo search respects GIT_CEILING_DIRECTORIES' '
+	test_when_finished rm -rf test &&
+
+	git init test/src &&
+	mkdir -p test/src/deep &&
+	GIT_CEILING_DIRECTORIES="$(pwd)/test/src" &&
+	! scalar register test/src/deep 2>err &&
+	grep "not a git repository" err
+'
+
+test_expect_success 'scalar enlistments need a worktree' '
+	test_when_finished rm -rf bare test &&
+
+	git init --bare bare/src &&
+	! scalar register bare/src 2>err &&
+	grep "Scalar enlistments require a worktree" err &&
+
+	git init test/src &&
+	! scalar register test/src/.git 2>err &&
+	grep "Scalar enlistments require a worktree" err
+'
+
 test_expect_success 'scalar unregister' '
 	git init vanish/src &&
 	scalar register vanish/src &&