Double check that read_buf is properly implemented.

flake.nix

@@ -4,24 +4,38 @@
   inputs = {
     nixpkgs.url = "github:NixOS/nixpkgs/nixpkgs-unstable";
     flake-utils.url = "github:numtide/flake-utils";
+    rust-overlay = {
+      url = "github:oxalica/rust-overlay";
+      inputs.nixpkgs.follows = "nixpkgs";
+    };
   };
 
   outputs =
     {
       self,
       nixpkgs,
       flake-utils,
+      rust-overlay,
+      ...
     }:
     flake-utils.lib.eachDefaultSystem (
       system:
       let
-        pkgs = import nixpkgs { inherit system; };
+        pkgs = import nixpkgs {
+          inherit system;
+          overlays = [ (import rust-overlay) ];
+        };
+
+        rust-toolchain = pkgs.rust-bin.stable.latest.default.override {
+          extensions = [
+            "rust-src"
+            "rust-analyzer"
+          ];
+          targets = [ "wasm32-unknown-unknown" ];
+        };
 
         tools = [
-          pkgs.rustc
-          pkgs.cargo
-          pkgs.rustfmt
-          pkgs.clippy
+          rust-toolchain
           pkgs.cargo-shear
           pkgs.cargo-sort
           pkgs.cargo-edit
@@ -40,7 +54,9 @@
           packages = tools;
 
           shellHook = ''
-            export LD_LIBRARY_PATH=${pkgs.lib.makeLibraryPath [pkgs.llvmPackages.libclang.lib]}:$LD_LIBRARY_PATH
+            export LD_LIBRARY_PATH=${
+              pkgs.lib.makeLibraryPath [ pkgs.llvmPackages.libclang.lib ]
+            }:$LD_LIBRARY_PATH
           '';
         };
       }

web-transport-quiche/src/ez/recv.rs

@@ -282,11 +282,11 @@ impl RecvStream {
             })
             .await?
         {
-            Some(n) => {
+            Some(n) if n > 0 => {
                 unsafe { buf.advance_mut(n) };
                 Ok(Some(n))
             }
-            None => Ok(None),
+            _ => Ok(None),
         }
     }
 

web-transport-trait/src/lib.rs

@@ -195,8 +195,8 @@ pub trait RecvStream: MaybeSend {
                 std::mem::transmute::<&mut bytes::buf::UninitSlice, &mut [u8]>(buf.chunk_mut())
             };
             let size = match self.read(dst).await? {
-                Some(size) => size,
-                None => return Ok(None),
+                Some(size) if size > 0 => size,
+                _ => return Ok(None),
             };
 
             unsafe { buf.advance_mut(size) };
@@ -253,8 +253,8 @@ pub trait RecvStream: MaybeSend {
             let mut size = 0;
             while buf.has_remaining_mut() {
                 match self.read_buf(buf).await? {
-                    Some(n) => size += n,
-                    None => break,
+                    Some(n) if n > 0 => size += n,
+                    _ => break,
                 }
             }
             Ok(size)

web-transport-wasm/src/recv.rs

@@ -55,8 +55,8 @@ impl RecvStream {
     /// Advances the buffer by the number of bytes read.
     pub async fn read_buf<B: BufMut>(&mut self, buf: &mut B) -> Result<Option<usize>, Error> {
         let chunk = match self.read(buf.remaining_mut()).await? {
-            Some(chunk) => chunk,
-            None => return Ok(None),
+            Some(chunk) if !chunk.is_empty() => chunk,
+            _ => return Ok(None),
         };
 
         let size = chunk.len();

web-transport-ws/src/session.rs

@@ -701,12 +701,12 @@ impl generic::RecvStream for RecvStream {
         }
 
         Ok(match self.read_chunk(buf.remaining_mut()).await? {
-            Some(data) => {
+            Some(data) if !data.is_empty() => {
                 let size = data.len();
                 buf.put(data);
                 Some(size)
             }
-            None => None,
+            _ => None,
         })
     }
 

web-transport/src/quinn.rs

@@ -259,8 +259,8 @@ impl RecvStream {
         let dst = unsafe { &mut *(dst as *mut _ as *mut [u8]) };
 
         let size = match self.inner.read(dst).await? {
-            Some(size) => size,
-            None => return Ok(None),
+            Some(size) if size > 0 => size,
+            _ => return Ok(None),
         };
 
         unsafe { buf.advance_mut(size) };