Rechannel: error when trying to send empty messages

rechannel/src/channel/block.rs

@@ -193,7 +193,7 @@ impl SendBlockChannel {
 
                     info!(
                         "Generated SliceMessage {} from chunk_id {}. ({}/{})",
-                        message.slice_id, self.chunk_id, message.slice_id, num_slices
+                        message.slice_id, self.chunk_id, message.slice_id + 1, *num_slices
                     );
 
                     slice_messages.push(message);
@@ -294,6 +294,12 @@ impl SendChannel for SendBlockChannel {
             return;
         }
 
+        if payload.is_empty() {
+            log::error!("Tried to send empty block message");
+            self.error = Some(ChannelError::SentEmptyMessage);
+            return;
+        }
+
         if payload.len() as u64 > self.max_message_size {
             log::error!(
                 "Tried to send block message with size above the limit, got {} bytes, expected less than {}",

rechannel/src/channel/reliable.rs

@@ -240,6 +240,12 @@ impl SendChannel for SendReliableChannel {
             return;
         }
 
+        if payload.is_empty() {
+            log::error!("Tried to send empty reliable message");
+            self.error = Some(ChannelError::SentEmptyMessage);
+            return;
+        }
+
         self.send_message_id = self.send_message_id.wrapping_add(1);
 
         let reliable_message = ReliableMessage::new(message_id, payload);

rechannel/src/channel/unreliable.rs

@@ -118,6 +118,12 @@ impl SendChannel for SendUnreliableChannel {
             return;
         }
 
+        if payload.is_empty() {
+            log::error!("Tried to send empty unreliable message");
+            self.error = Some(ChannelError::SentEmptyMessage);
+            return;
+        }
+
         if self.messages_to_send.len() >= self.message_send_queue_size {
             self.error = Some(ChannelError::SendQueueFull);
             log::warn!("Unreliable channel {} has reached the maximum queue size", self.channel_id);

rechannel/src/error.rs

@@ -31,6 +31,8 @@ pub enum ChannelError {
     FailedToSerialize,
     /// Tried to send a message that is above the channel max message size.
     SentMessageAboveMaxSize,
+    /// Tried to send an empty message
+    SentEmptyMessage,
     /// Received a message above above the channel max message size.
     ReceivedMessageAboveMaxSize,
     /// Received an invalid slice message in a block channel.
@@ -46,6 +48,7 @@ impl fmt::Display for ChannelError {
             SendQueueFull => write!(fmt, "send queue was full"),
             FailedToSerialize => write!(fmt, "failed to serialize or deserialize"),
             SentMessageAboveMaxSize => write!(fmt, "sent message above the channel max message size"),
+            SentEmptyMessage => write!(fmt, "sent empty message"),
             ReceivedMessageAboveMaxSize => write!(fmt, "received message above the channel max message size"),
             InvalidSliceMessage => write!(fmt, "received an invalid slice message in a block channel"),
         }