From 84592548fa16d630be09f9e063d3678bb1a7831a Mon Sep 17 00:00:00 2001
From: Tesfa Mael <tesfa@wolfssl.com>
Date: Thu, 29 Oct 2020 16:15:55 -0700
Subject: [PATCH] Raise error when wolfSSL_write() returns 0

---
 src/wolfssl/__init__.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/wolfssl/__init__.py b/src/wolfssl/__init__.py
index 8b4098c..27d1f2c 100644
--- a/src/wolfssl/__init__.py
+++ b/src/wolfssl/__init__.py
@@ -543,7 +543,8 @@ class SSLSocket(object):
 
         while sent < length:
             ret = self.write(data[sent:])
-            if (ret < 0):
+            if (ret <= 0):
+                #expect to receive 0 when peer is reset or closed
                 err = _lib.wolfSSL_get_error(self.native_object, 0)
                 if err == _SSL_ERROR_WANT_WRITE:
                     raise SSLWantWriteError()