commit fc568ff045e6a8956221c3f095ed8e7200fa5f74
Author: zhenhaonong <zhenhaonong@tencent.com>
Date:   2023-03-17 19:53:50 +0800

    Deal with partial writes on SSL write
    
    SSL write may do partial writes in some cases. For example, document
    of mbedtls_ssl_write says:
      If the return value is non-negative but less than length, the function
      must be called again with updated arguments: buf + ret, len - ret
      (if ret is the return value) until it returns a value equal to the
      last 'len' argument.
    
    In case of partial writes, we should continue writing the same chain of
    buffer, not the next chain.

...