From 3d2ac056d6f216e762510beedab795c166df3f8b Mon Sep 17 00:00:00 2001
From: oblique <psyberbits@gmail.com>
Date: Sun, 18 Sep 2022 01:03:14 +0300
Subject: [PATCH] Return error on empty name

---
 src/error.rs |  3 +++
 src/lib.rs   | 32 ++++++++++++++++++++++++++++++--
 2 files changed, 33 insertions(+), 2 deletions(-)

diff --git a/src/error.rs b/src/error.rs
index 1b3c2be..7a1e2d4 100644
--- a/src/error.rs
+++ b/src/error.rs
@@ -9,6 +9,9 @@ pub enum Error {
     #[error("Invalid character in name")]
     InvalidCharacter,
 
+    #[error("Name must not be empty")]
+    EmptyName,
+
     #[error("Failed to create named lock: {0}")]
     CreateFailed(#[source] std::io::Error),
 
diff --git a/src/lib.rs b/src/lib.rs
index c2a8fea..15e5032 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -78,11 +78,19 @@ impl NamedLock {
     ///
     /// This will create/open a [global] mutex with [`CreateMutexW`].
     ///
+    /// # Notes
+    ///
+    /// * `name` must not be empty, otherwise an error is returned.
+    /// * `name` must not contain `\0`, `/`, nor `\`, otherwise an error is returned.
     ///
     /// [`flock`]: https://linux.die.net/man/2/flock
     /// [global]: https://docs.microsoft.com/en-us/windows/win32/termserv/kernel-object-namespaces
     /// [`CreateMutexW`]: https://docs.microsoft.com/en-us/windows/win32/api/synchapi/nf-synchapi-createmutexw
     pub fn create(name: &str) -> Result<NamedLock> {
+        if name.is_empty() {
+            return Err(Error::EmptyName);
+        }
+
         // On UNIX we want to restrict the user on `/tmp` directory,
         // so we block the `/` character.
         //
@@ -112,8 +120,8 @@ impl NamedLock {
     ///
     /// # Notes
     ///
-    /// * This function does not append `.lock` on the path
-    /// * Parent directories must exist
+    /// * This function does not append `.lock` on the path.
+    /// * Parent directories must exist.
     #[cfg(unix)]
     #[cfg_attr(docsrs, doc(cfg(unix)))]
     pub fn with_path<P>(path: P) -> Result<NamedLock>
@@ -263,4 +271,24 @@ mod tests {
 
         Ok(())
     }
+
+    #[test]
+    fn invalid_names() {
+        assert!(matches!(NamedLock::create(""), Err(Error::EmptyName)));
+
+        assert!(matches!(
+            NamedLock::create("abc/"),
+            Err(Error::InvalidCharacter)
+        ));
+
+        assert!(matches!(
+            NamedLock::create("abc\\"),
+            Err(Error::InvalidCharacter)
+        ));
+
+        assert!(matches!(
+            NamedLock::create("abc\0"),
+            Err(Error::InvalidCharacter)
+        ));
+    }
 }