don't send info packet if downgraded

wisp/src/lib.rs

@@ -763,17 +763,20 @@ impl ClientMux {
 			let (supported_extensions, extra_packet, downgraded) =
 				if let Some(builders) = extension_builders {
 					let x = maybe_wisp_v2(&mut read, &write, builders).await?;
-					write
+					// if not downgraded
-						.write_frame(
+					if !x.2 {
-							Packet::new_info(
+						write
-								builders
+							.write_frame(
-									.iter()
+								Packet::new_info(
-									.map(|x| x.build_to_extension(Role::Client))
+									builders
-									.collect(),
+										.iter()
+										.map(|x| x.build_to_extension(Role::Client))
+										.collect(),
+								)
+								.into(),
 							)
-							.into(),
+							.await?;
-						)
+					}
-						.await?;
 					x
 				} else {
 					(Vec::new(), None, true)

wisp/src/stream.rs

@@ -215,7 +215,7 @@ impl MuxStreamWrite {
 		))
 	}
 
-	/// Turn the write half into one that implements futures `Sink`, consuming it. 
+	/// Turn the write half into one that implements futures `Sink`, consuming it.
 	pub fn into_sink(self) -> MuxStreamIoSink {
 		MuxStreamIoSink {
 			tx: self.into_inner_sink(),