chore: allow the entiry request or response body to be deleted

Author: Wim Spaargaren

proxywasm/hostcall.go

@@ -130,7 +130,8 @@ func GetHttpRequestBody(start, maxSize int) ([]byte, error) {
 
 func SetHttpRequestBody(body []byte) error {
 	if len(body) == 0 {
-		return types.StatusToError(types.StatusBadArgument)
+		st := rawhostcall.ProxySetBufferBytes(types.BufferTypeHttpRequestBody, 0, len(body), nil, len(body))
+		return types.StatusToError(st)
 	}
 	bufferData := &body[0]
 	st := rawhostcall.ProxySetBufferBytes(types.BufferTypeHttpRequestBody, 0, len(body), bufferData, len(body))
@@ -200,7 +201,8 @@ func GetHttpResponseBody(start, maxSize int) ([]byte, error) {
 
 func SetHttpResponseBody(body []byte) error {
 	if len(body) == 0 {
-		return types.StatusToError(types.StatusBadArgument)
+		st := rawhostcall.ProxySetBufferBytes(types.BufferTypeHttpRequestBody, 0, len(body), nil, len(body))
+		return types.StatusToError(st)
 	}
 	bufferData := &body[0]
 	st := rawhostcall.ProxySetBufferBytes(types.BufferTypeHttpResponseBody, 0, len(body), bufferData, len(body))