Reject ZST

Author: apfitzge

src/mpmc.rs

@@ -539,6 +539,10 @@ impl SharedQueueHeader {
     }
 
     const fn calculate_buffer_size_in_items<T: Sized>(file_size: usize) -> Result<usize, Error> {
+        if core::mem::size_of::<T>() == 0 {
+            return Err(Error::InvalidBufferSize);
+        }
+
         let buffer_offset = Self::buffer_offset::<T>();
         if file_size < buffer_offset {
             return Err(Error::InvalidBufferSize);
@@ -938,6 +942,17 @@ mod tests {
         }
     }
 
+    #[test]
+    fn test_zero_sized_types_are_rejected() {
+        let file = create_temp_shmem_file().unwrap();
+        let err = match unsafe { Producer::<()>::create(&file, minimum_file_size::<()>(8)) } {
+            Ok(_) => panic!("zst queue creation should fail"),
+            Err(err) => err,
+        };
+
+        assert!(matches!(err, Error::InvalidBufferSize));
+    }
+
     #[test]
     fn test_try_write_slice() {
         let (_file, producer, consumer) = create_test_queue::<Item>(BUFFER_SIZE);

src/spsc.rs

@@ -409,6 +409,10 @@ impl SharedQueueHeader {
     }
 
     const fn calculate_buffer_size_in_items<T: Sized>(file_size: usize) -> Result<usize, Error> {
+        if core::mem::size_of::<T>() == 0 {
+            return Err(Error::InvalidBufferSize);
+        }
+
         let buffer_offset = Self::buffer_offset::<T>();
         if file_size < buffer_offset {
             return Err(Error::InvalidBufferSize);
@@ -623,4 +627,15 @@ mod tests {
 
         assert_eq!(producer.capacity(), 4);
     }
+
+    #[test]
+    fn test_zero_sized_types_are_rejected() {
+        let file = create_temp_shmem_file().unwrap();
+        let err = match unsafe { Producer::<()>::create(&file, minimum_file_size::<()>(8)) } {
+            Ok(_) => panic!("zst queue creation should fail"),
+            Err(err) => err,
+        };
+
+        assert!(matches!(err, Error::InvalidBufferSize));
+    }
 }