fix remaining issues found by tests

connect.go

@@ -377,7 +377,7 @@ func receiveUnaryResponse[T any](conn StreamingClientConn, initializer maybeInit
 	if err := conn.Receive(&msg2); err == nil {
 		return nil, NewError(CodeUnknown, errors.New("unary stream has multiple messages"))
 	} else if err != nil && !errors.Is(err, io.EOF) {
-		return nil, NewError(CodeUnknown, err)
+		return nil, err
 	}
 	return &Response[T]{
 		Msg:     &msg,

duplex_http_call.go

@@ -183,13 +183,15 @@ func (d *duplexHTTPCall) CloseRead() error {
 	if d.response == nil {
 		return nil
 	}
-	if _, err := discard(d.response.Body); err != nil &&
-		!errors.Is(err, context.Canceled) &&
-		!errors.Is(err, context.DeadlineExceeded) {
-		_ = d.response.Body.Close()
-		return wrapIfRSTError(err)
+	_, err := discard(d.response.Body)
+	closeErr := d.response.Body.Close()
+	if err == nil ||
+		errors.Is(err, context.Canceled) ||
+		errors.Is(err, context.DeadlineExceeded) {
+		err = closeErr
 	}
-	return wrapIfRSTError(d.response.Body.Close())
+	err = wrapIfContextError(err)
+	return wrapIfRSTError(err)
 }
 
 // ResponseStatusCode is the response's HTTP status code.

envelope.go

@@ -206,6 +206,10 @@ func (r *envelopeReader) Unmarshal(message any) *Error {
 	if env.Flags != 0 && env.Flags != flagEnvelopeCompressed {
 		// Drain the rest of the stream to ensure there is no extra data.
 		if n, err := discard(r.reader); err != nil {
+			err = wrapIfContextError(err)
+			if connErr, ok := asError(err); ok {
+				return connErr
+			}
 			return errorf(CodeInternal, "corrupt response: I/O error after end-stream message: %w", err)
 		} else if n > 0 {
 			return errorf(CodeInternal, "corrupt response: %d extra bytes after end of stream", n)